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High‐performance compact capacitive energy storage is vital for many modern application fields, including grid power buffers, electric vehicles, and portable electronics. However, achieving exceptional volumetric performance in supercapacitors is still challenging and requires effective fabrication of electrode films with high ion‐accessible surface area and fast ion diffusion capability while simultaneously maintaining high density. Herein, a facile, efficient, and scalable method is developed for the fabrication of dense, porous, and disordered graphene through spark‐induced disorderly opening of graphene stacks combined with mechanical compression. The obtained disordered graphene achieves a high density of 1.18 g cm−3, sixfold enhanced ion conductivity compared to common laminar graphene, and an ultrahigh volumetric capacitance of 297 F cm−3 in ionic liquid electrolyte. The fabricated stack cells deliver a volumetric energy density of 94.2 Wh L−1 and a power density of 13.7 kW L−1, representing a critical breakthrough in capacitive energy storage. Moreover, the proposed disordered graphene electrodes are assembled into ionogel‐based all‐solid‐state pouch cells with high mechanical stability and multiple optional outputs, demonstrating great potential for flexible energy storage in practical applications. [ABSTRACT FROM AUTHOR]

The two-phase protection layers induce a reinforcement effect on the Zn anode. Specifically, Sb nanoparticles can act as nucleation sites to promote the uniform Zn deposition and homogenize the electric field around the Zn surface. While ZHS micrometer-size sheets possess sufficient electrolyte wettability, fasting ion transfer kinetics and anti-corrosion, and thus guaranteeing uniform ion flux and suppressing dendrite growth and side reactions. [Display omitted] Rechargeable aqueous zinc ion batteries with abundant resources and high safety have gained extensive attention in energy storage technology. However, the cycle stability is largely limited by notorious Zn dendrite growth and water-induced interfacial side reactions. Here, a uniform and robust protection layer consisting of metal antimony (Sb) nanoparticles and micrometer-size sheets Zn 4 (OH) 6 SO 4 ·5H 2 O (ZHS) is purposely designed to stabilize Zn anode via an in situ chemical reaction strategy. The two-phase protection layers (Sb/ZHS) induce a reinforcement effect on the Zn anode (Zn@Sb/ZHS). Specifically, Sb nanoparticles play the part of nucleation sites to facilitate uniform Zn plating and homogenize the electric field around the Zn surface. ZHS micrometer-size sheets possess sufficient electrolyte wettability, fast ion transfer kinetics, and anti-corrosion, thus guaranteeing uniform ion flux and inhibiting H 2 O decomposition. As expected, the symmetric Zn@Sb/ZHS//Zn@Sb/ZHS cells achieve a minimal voltage hysteresis and a reversible cycle of over 2000 h at 1 mA cm−2. By pairing with the MnO 2 cathode, the full cell exhibits a significantly improved stability (∼94.17 % initial capacity after 1500 cycles). This study provides a new strategy to design artificial protection layers. [ABSTRACT FROM AUTHOR]

The vibrational‐translational (VT) excitation of nitrogen molecules led by collisions with fast ions in subauroral ion drifts (SAID) has been conceived as a potential underlying mechanism contributing to the formation of the Strong Thermal Emission Velocity Enhancement (STEVE) phenomenon (Harding et al., 2020, https://doi.org/10.1029/2020gl087102). In this study, we perform quantum calculations of the VT excitation rates of N2 led by fast‐drifting ions, and evaluate the resulting vibrational distribution of N2 with ionospheric/thermospheric parameters expected under intense SAID condition. We conclude that, while the VT energy transfer led by SAID plays a distinguishable role in the vibrational excitation of N2, it is incapable of populating the high vibrational levels to the required concentration (Harding et al., 2020, https://doi.org/10.1029/2020gl087102) to produce adequate nitric oxide density, and in turn the nitrogen‐dioxide continuum intensity, to account for the STEVE brightness. Plain Language Summary: A night sky phenomenon known as STEVE has captured the attention of scientists and citizen scientists in recent years. It is known that STEVE is inherently related to a special process termed "subauroral ion drifts (SAID)", namely a rapid westward drift of plasma in the Earth's ionosphere. It was thus hypothesized that a collision between fast ions and the nitrogen molecules (N2) may cause the kinetic energy of ions being transferred to the internal energy of N2, which can facilitate the chemical reactions leading to STEVE emissions. In this study, we perform quantum calculations of the energy transfer between fast ions and N2 and conclude that, such energy transfer is inefficient under realistic SAID conditions and incapable of accounting for the STEVE emission. Key Points: We perform quantum calculations of the vibrational‐translational (VT) excitation rates of nitrogen molecules (N2) led by fast‐drifting ionsWe calculate the N2 vibrational distribution including VT excitation with ionospheric/thermospheric parameters expected under SAID conditionWe assess that VT excitation led by SAID is unable to provide adequate high‐level excited N2 population to account for the STEVE brightness [ABSTRACT FROM AUTHOR]

The current driven by neutral beam injection in tokamak is calculated, and the slowing-down distribution function of the fast ion is obtained by the backward Euler iteration method, including the pitch angle scattering collision. This study reveals that when the pitch-angle cosine is small, the trapped fast-ion current significantly contributes to the total driven current, particularly when the neutral beam is injected perpendicularly. In such cases, the current densities of passing and trapped ions are of the same order of magnitude, with the trapped fast-ion current contributing over 10% to the total neutral beam-driven current. This results in a parabolic profile of the total current in the radial direction, promoting the formation of a negative shear equilibrium structure in the core of the tokamak plasma. The numerical approach was validated against the NUBEAM code while considering electron shielding effects and applied to calculate the neutral beam-driven current in multiple tokamaks. The influence of pitch-angle cosine and neutral beam injection power on the driven current was studied at different radial positions. [ABSTRACT FROM AUTHOR]

Tuning interphase chemistry to stabilize high-voltage NaNi 1/3 Fe 1/3 Mn 1/3 O 2 cathode via bonding superionic conductor interface. [Display omitted] • NASICON-type Na 3 V 2 (PO 4) 3 is bonded on NaNi 1/3 Fe 1/3 Mn 1/3 O 2 surface. • The coating layer inhibits surface parasitic reactions and TMs dissolution. • Fast Na+ kinetic and high rate capacity are achieved for the composite electrode. Unstable cathode/electrolyte interphase and severe interfacial side reaction have long been identified as the main cause for the failure of layered oxide cathode during fast charging and long-term cycling for rechargeable sodium-ion batteries. Here, we report a superionic conductor (Na 3 V 2 (PO 4) 3 , NVP) bonding surface strategy for O3-type layered NaNi 1/3 Fe 1/3 Mn 1/3 O 2 (NFM) cathode to suppress electrolyte corrosion and near-surface structure deconstruction, especially at high operating potential. The strong bonding affinity at the NVP/NFM contact interface stabilizes the crystal structure by inhibiting surface parasitic reactions and transition metal dissolution, thus significantly improving the phase change reversibility at high desodiation state and prolonging the lifespan of NFM cathode. Due to the high-electron-conductivity of NFM, the redox activity of NVP is also enhanced to provide additional capacity. Therefore, benefiting from the fast ion transport kinetics and electrochemical Na+-storage activity of NVP, the composite NFM@NVP electrode displays a high initial coulombic efficiency of 95.5 % at 0.1 C and excellent rate capability (100 mAh g−1 at 20 C) within high cutoff voltage of 4.2 V. The optimized cathode also delivers preeminent cyclic stability with ∼80 % capacity retention after 500 cycles at 2 C. This work sheds light on a facile and universal strategy on improving interphase stability to develop fast-charging and sustainable batteries. [ABSTRACT FROM AUTHOR]

[Display omitted] Transition-metal phosphates/phosphides showcase significant promise for energy-related applications because of their high theoretical electrochemical characteristics. However, sluggish electro/ion transfer rates and kinetically unfavorable reaction sites hinder their application at high mass loading. Herein, a self-supporting electrode based on transition-metal phosphates was successfully fabricated via a one-step electrodeposition process. The nanosheet structure of transition-metal phosphates, formed by interconnecting nanoparticles, effectively mitigates the impact of stress and achieves a high mass-loading (21 mg cm−2) of the electrode. Additionally, the oxygen vacancy-rich and porous nanostructure of transition-metal phosphates endows the as-prepared electrodes with a significantly increased conductivity and fast ion migration rate for enhancing electrochemical kinetics. Consequently, the as-fabricated transition-metal phosphate electrode displays the highest areal specific capacity of 39.2F cm−2. Furthermore, the asymmetric supercapacitor achieves a maximum energy density of 0.79 mWh cm−2 and a high capacity retention of 93.0 % for 10000 cycles under 60 mA cm−2. This work provides an ideal strategy for fabricating flexible electrodes with high mass loading and synthesizing transition-metal phosphate electrodes rich in oxygen vacancies. [ABSTRACT FROM AUTHOR]

[Display omitted] The unique design of the core–shell heterostructure is significant for obtaining electrode materials with excellent electrochemical properties. In this paper, porous carbon nanofibers (NPC@PPZ) embedded with N -doped porous carbon nanoparticles are used to construct flexible electrodes (NPC@PPZ@Bi 2 O 3). Zeolite imidazole skeleton (ZIF)-8 and poly(methyl methacrylate) (PMMA) derived porous carbon fibers and Bi 2 O 3 nanosheets, were utilized as the porous core and multilayer shell, respectively. The unique core and shell result in abundant pores and channels for fast ion transport and storage, high specific surface area, and additional electroactive sites. This perfect structural design enables the NPC@PPZ@Bi 2 O 3 composite electrode to have excellent electrochemical performance. The results show that this electrode can obtain a high specific capacitance of 697 F g−1 at a current density of 1 A g−1 and a stable cycling performance at a high current density of 5 A g−1. The strategy developed in this study provides a new approach for the design and fabrication of flexible supercapacitors by electrostatic spinning combined with hierarchical porous structures. [ABSTRACT FROM AUTHOR]

Nanofluidic energy harvesting from salinity gradients is studied in 2D nanomaterials‐based membranes with promising performance as high ion selectivity and fast ion transport. In addition, moving forward to scalable, feasible systems requires environmentally friendly materials to make the application sustainable. Clay‐based membranes are attractive for being environmentally friendly, non‐hazardous, and easy to manipulate materials. However, achieving underwater stability for clay‐based membranes remains challenging. In this work, the synthetic clay Laponite is used to prepare clay‐based membranes with high stability and excellent performance for osmotic energy harvesting. The Laponite membranes (Lap‐membranes) are stabilized by low‐temperature annealing treatment to effectively reduce the interlayer space, achieving a continuous operation under salinity gradients. Furthermore, the Lap‐membranes conserve integrity while soaking in water for more than one month. The output power density improves from ≈4.97 W m−2 on the pristine membrane to ≈9.89 W m−2 in the membrane treated 12 h at 300 °C from a 30‐fold concentration gradient. Especially, It is found that the presence of interlayer water to be favorable for ion transport. Different mechanisms are proposed in the Lap‐membranes involved for efficient ion selectivity and the states found with varying annealing temperatures. This work demonstrates the potential application of Laponite based nanomaterials for nanofluidic energy harvesting. [ABSTRACT FROM AUTHOR]

The scalable fabrication of cost-efficient bifunctional catalysts with enhanced hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) performance plays a significant role in overall water splitting in hydrogen production fields. MoSe2 is considered to be one of the most promising candidates because of its low cost and high catalytic activity. Herein, hierarchical nitrogen-doped carbon networks were constructed to enhance the catalytic activity of the MoSe2-based materials by scalable free-drying combined with an in situ selenization strategy. The rationally designed carbonaceous network-encapsulated MoSe2 composite (MoSe2/NC) endows a continuous honeycomb-like structure. When utilized as a bifunctional electrocatalyst for both HER and OER, the MoSe2/NC electrode exhibits excellent electrochemical performance. Significantly, the MoSe2/NC‖MoSe2/NC cells require a mere 1.5 V to reach a current density of 10 mA cm−2 for overall water splitting in 1 M KOH. Ex situ characterizations and electrochemical kinetic analysis reveal that the superior catalytic performance of the MoSe2/NC composite is mainly attributed to fast electron and ion transportation and good structural stability, which is derived from the abundant active sites and excellent structural flexibility of the honeycomb-like carbon network. This work offers a promising pathway to the scalable fabrication of advanced non-noble bifunctional electrodes for highly efficient hydrogen evolution. [ABSTRACT FROM AUTHOR]

Porous hard carbon with good cycling durability attracts much attention in the application of sodium ions batteries as anode material, but the commonly used alkali metal ion-activation strategy with complex processes still renders its development. Herein, a simple and scalable method is proposed to synthesize hierarchical porous hard carbon. Benefitting from the efficient self-activation strategy, the hierarchical micro–mesoporous hard carbon (MMHC) with large interlayer distance possesses high specific surface area of 704.1 m2 g−1, which can provide shorter ionic diffusion path and much more accessible electrochemical active sites in the carbonaceous structure and then lead to fast sodium ion diffusivity kinetics (3.5 × 10–9 cm2 s−1). In consequence, MMHC electrode delivers high specific capacity of 214.3 mAh g−1 at 50 mA g−1, 118.3 mAh g−1 at 500 mA g−1 after 1000 cycles and 47.4 mAh g−1 even at 4000 mA g−1. Notably, the capacity contribution ratio from low-voltage range is enhanced with engineering micro–mesoporous structure (from 28.5% for HC to 37.7% for MMHC). Promisingly, the hierarchical micro–mesoporous hard carbon holds great potential in commercial sodium ions batteries. [ABSTRACT FROM AUTHOR]

[Display omitted] • The electrochemical properties of BG are significantly enhanced by the morphology of the constructed wool-like clusters. • The optimized BG-2 exhibits excellent rate performance and cycling stability. • The appropriate iron content in 3D skeletons opens a new possibility for enhancing ammonium ion storage. Prussian blue analogues (PBAs) are regarded as promising cathode materials for ammonium-ion batteries (AIBs) because of their low cost and superb theoretical capacity. However, its inherently poor conductivity and structural collapse can significantly limit the enhancement of rate property and cycling stability. In this work, Berlin Green (BG) electrode materials with similar wool-like clusters were constructed by direct precipitation method to accelerate the kinetic, which realizes outstanding cycling stability. Berlin Green with the appropriate amount of iron (BG-2) has a fast ion transport channel, enhanced structure stability, highly reversible insertion/extraction of NH 4 +, and fine electrochemical reaction activity. Benefiting from the unique architecture and component, the BG-2 electrode shows an excellent rate performance with a discharge/charge specific capacity of 60.1/59.3 mAh g−1 at 5 A g−1. Even at 5 A g−1, BG-2 exhibits remarkable cycling stability with an initial discharge capacity of 59.5 mAh g−1 and a capacity retention rate of approximately 76% after 30,000 cycles. The BG-2 reveals exceedingly good electrochemical reversibility during the process of NH 4 + (de)insertion. BG materials indicate huge potential as a cathode material for the next generation of high-performance aqueous batteries. [ABSTRACT FROM AUTHOR]

Rechargeable multivalent‐ion batteries are attractive alternatives to Li‐ion batteries to mitigate their issues with metal resources and metal anodes. However, many challenges remain before they can be practically used due to the low solid‐state mobility of multivalent ions. In this study, a promising material identified by high‐throughput computational screening is investigated, ε‐VOPO4, as a Mg cathode. The experimental and computational evaluation of ε‐VOPO4 suggests that it may provide an energy density of >200 Wh kg−1 based on the average voltage of a complete cycle, significantly more than that of well‐known Chevrel compounds. Furthermore, this study finds that Mg‐ion diffusion can be enhanced by co‐intercalation of Li or Na, pointing at interesting correlation dynamics of slow and fast ions. [ABSTRACT FROM AUTHOR]

Zinc-ion capacitors (ZICs), combining the merits of both high-energy zinc-ion batteries and high-power supercapacitors, are known as high-potential electrochemical energy storage (EES) devices. However, the research on ZICs still faces many challenges because of the lack of appropriate cathode materials with robust crystal structures and rich channels for stable and fast Zn2+ ion transport. In this study, we synthesized a robust, conductive, two-dimensional metal–organic framework (MOF) material, zinc-benzenehexathiolate (Zn-BHT), and investigated its electrochemical performance for zinc storage. Zn2+ ions could insert into/extricate from the host structure with a high diffusion rate, enabling the Zn-BHT cathode to exhibit a surface-controlled charge storage mechanism. Due to its unique structure, Zn-BHT exhibited a good reversible discharge capacity approaching 90.4 mAh g−1 at 0.1 A g−1, as well as a desirable rate capability and good cycling performance. In addition, a ZIC device was fabricated using the Zn-BHT cathode and a polyaniline-derived porous carbon (PC) anode, which depicted a high working voltage of up to 1.8 V and a high energy density of ~37.2 Wh kg−1. This work shows that conductive MOFs are high-potential electrode materials for ZICs and provide new enlightenment for the development of electrode materials for EES devices. [ABSTRACT FROM AUTHOR]

This work reviews the progression of chemical analysis via Cherenkov emissions, i.e., Cherenkov Photometry and Cherenkov Emission Spectroscopy, from its introduction in the literature up to modern developments. In presenting the history of this field, we aim to consolidate the literature, both for reference and contextualization. We present an argument aiming to untangle why this corner of research has seen little progress while so many other directly related aspects of Cherenkov research have flourished, as well as speak to the progress of the field in recent years and prospective direction in years to come. [ABSTRACT FROM AUTHOR]

Designing innovative anode materials that exhibit excellent ion diffusion kinetics, enhanced structural stability, and superior electrical conductivity is imperative for advancing the rapid charge–discharge performance and widespread application of sodium-ion batteries. Hollow-structured materials have received significant attention in electrode design due to their rapid ion diffusion kinetics. Building upon this, we present a high-performance, free-standing MoO2@hollow carbon nanofiber (MoO2@HCNF) electrode, fabricated through facile coaxial electrospinning and subsequent heat treatment. In comparison to MoO2@carbon nanofibers (MoO2@CNFs), the MoO2@HCNF electrode demonstrates superior rate capability, attributed to its larger specific surface area, its higher pseudocapacitance contribution, and the enhanced diffusion kinetics of sodium ions. The discharge capacities of the MoO2@HCNF (MoO2@CNF) electrode at current densities of 0.1, 0.2, 0.5, 1.0, 2.0 and 5.0 A g−1 are 195.55 (155.49), 180.98 (135.20), 163.81 (109.71), 144.05 (90.46), 121.16 (71.21) and 88.90 (44.68) mAh g−1, respectively. Additionally, the diffusion coefficients of sodium ions in the MoO2@HCNFs are 8.74 × 10−12 to 1.37 × 10−12 cm2 s−1, which surpass those of the MoO2@CNFs (6.49 × 10−12 to 9.30 × 10−13 cm2 s−1) during the discharging process. In addition, these prepared electrode materials exhibit outstanding flexibility, which is crucial to the power storage industry and smart wearable devices. [ABSTRACT FROM AUTHOR]

Fast transport of monovalent ions is imperative in selective monovalent ion separation based on membranes. Here, we report the in situ growth of crown ether@UiO-66 membranes at a mild condition, where dibenzo-18-crown-6 (DB18C6) or dibenzo-15-crown-5 is perfectly confined in the UiO-66 cavity. Crown ether@UiO-66 membranes exhibit enhanced monovalent ion transport rates and mono-/divalent ion selectivity, due to the combination of size sieving and interaction screening effects toward the complete monovalent ion dehydration. Specifically, the DB18C6@UiO-66 membrane shows a permeation rate (e.g., K+) of 1.2 mol per square meter per hour and a mono-/ divalent ion selectivity (e.g., K+/Mg2+) of 57. Theoretical calculations and simulations illustrate that, presumably, ions are completely dehydrated while transporting through the DB18C6@UiO-66 cavity with a lower energy barrier than that of the UiO-66 cavity. This work provides a strategy to develop efficient ion separation membranes via integrating size sieving and interaction screening and to illuminate the effect of ion dehydration on fast ion transport. [ABSTRACT FROM AUTHOR]

The toroidal single-fluid magnetohydrodynamic (MHD) code MARS-F (Liu et al 2000 Phys. Plasmas 7 3681) and the MHD-kinetic hybrid code MARS-K (Liu et al 2008 Phys. Plasmas 15 112503) are utilized to study the plasma response to the n = 1 (n is the toroidal mode number) resonant magnetic perturbation (RMP), applied to suppress the type-I edge localized mode (ELM) in a KSTAR discharge. Both the resistive-rotating and ideal-static plasma models identify strong screening of the resonant radial field harmonics of the applied RMP due to the plasma response, and predict a strong edge-peeling response of the plasma which is consistent with the optimal ELM control coil current configuration adopted in experiment. The RMP-induced radial displacement of the plasma, computed by the resistive-rotating plasma model, agrees reasonably well with that reconstructed from the measured data in the plasma core. Taking into account the drift kinetic response of fast ions, MARS-K hybrid modeling also finds quantitative agreement of the plasma core fluid pressure perturbation with experiment. Based on the MARS-F computed plasma response, a guiding-center orbit-tracing simulation finds about 0.3% of fast ion losses due the n = 1 RMP in the KSTAR ELM control experiment considered. Most losses are associated with counter-current fast ions located near the plasma edge. [ABSTRACT FROM AUTHOR]

Conventionally, neutral beam injection (NBI) in tokamaks is controlled via engineering parameters such as injection voltage and power. Recently, the high-fidelity real-time NBI code RABBIT has been coupled to the discharge control system of ASDEX Upgrade. It allows to calculate the NBI fast-ion distribution and hence the properties of NBI in real-time, making it possible to control them directly. We successfully demonstrate control of driven current, ion heating and stored fast-ion energy by modifying the injected beam power. A combined ECRH and NBI controller is also successfully tested, which is able to adjust the heating mix between ECRH and NBI to match a certain desired ion heating fraction at given total power. Further experiments have been carried out towards control of the ion heat flux (i.e. ion heating plus collisional heat transfer between ions and electrons). They show good initial success, but also leave room for future improvements as the controller runs into instabilities at too high requests. [ABSTRACT FROM AUTHOR]

Observational data at heliocentric distances of tens of solar radii suggest that fast magnetosonic modes make up a considerable fraction of the solar wind fluctuations. Furthermore, this fraction appears to increase closer to the Sun. We carry out three-dimensional kinetic simulations with particle ions and fluid electrons to evaluate the proton and alpha-particle heating produced by the damping of the fast waves in the solar corona. Realistic parameters at 5 solar radii, including the fluctuation amplitude, are used. We show that, due to the cyclotron resonance, the alphas are heated preferentially perpendicularly to the magnetic field and much more strongly than the protons. The presence of the alpha particles alters the energy partition by reducing the heating of the protons. Nevertheless, the proton heating is sufficient to account for the solar wind acceleration. [ABSTRACT FROM AUTHOR]

Since the 1980s, the paddlewheel effect has been suggested as a mechanism to boost lithium- ion diffusion in inorganic materials via the rotation of rotor- like anion groups. However, it remains unclear whether the paddlewheel effect, defined as large- angle anion group rotations assisting Li hopping, indeed exists; furthermore, the physical mechanism by which the anion- group dynamics affect lithium- ion diffusion has not yet been established. In this work, we differentiate various types of rotational motions of anion groups and develop quaternion- based algorithms to detect, quantify, and relate them to lithium- ion motion in ab initio molecular dynamics simulations. Our analysis demonstrates that, in fact, the paddlewheel effect, where an anion group makes a large angle rotation to assist a lithium- ion hop, does not exist and thus is not responsible for the fast lithium- ion diffusion in superionic conductors, as historically claimed. Instead, we find that materials with topologically isolated anion groups can enhance lithium- ion diffusivity via a more classic nondynamic soft- cradle mechanism, where the anion groups tilt to provide optimal coordination to a lithium ion throughout the hopping process to lower the migration barrier. This anion- group disorder is static in nature, rather than dynamic and can explain most of the experimental observations. Our work substantiates the nonexistence of the long- debated paddlewheel effect and clarifies any correlation that may exist between anion- group rotations and fast ionic diffusion in inorganic materials. [ABSTRACT FROM AUTHOR]

The phenomenon known as strong thermal emission velocity enhancement (STEVE) is a purple/mauve arc-shaped atmospheric glow observed at lower latitudes of the auroral oval on the duskside. Simultaneous observations using a ground-based camera and a low-altitude satellite have shown that STEVE is accompanied by rapid westward ion flows. Such fast ion flows are termed the subauroral ion drift (SAID) or subauroral polarization stream (SAPS). Similarly, an eastward fast ion flow known as the dawnside auroral polarization stream (DAPS) is observed within the Region 1 current on the dawnside. If the optical phenomenon triggered by SAID/SAPS corresponds to STEVE, a comparable optical phenomenon should be driven by DAPS. Thus far, however, such a phenomenon has not been reported. This study discovers, for the first time, a purple-colored optical phenomenon characterized by the fast eastward ion flows, a possible signature of DAPS, occurring poleward of the bright green arc in the post-midnight sector. We present color all-sky images obtained by a ground-based commercial digital camera, along with wide-coverage optical measurements and in-situ data from low-altitude satellites. The results imply that this glow requires not only a high-speed ion flow but also its sharp latitudinal gradient at the boundary between the Region 1 and 2. [ABSTRACT FROM AUTHOR]

Rechargeable aqueous zinc-ion batteries have attracted a lot of attention owing to their cost effectiveness and plentiful resources, but less research has been conducted on the aspect of high volumetric energy density, which is crucial to the space available for the batteries in practical applications. In this work, highly crystalline V2O5 microspheres were self-assembled from one-dimensional V2O5 nanorod structures by a template-free solvothermal method, which were used as cathode materials for zinc-ion batteries with high performance, enabling fast ion transport, outstanding cycle stability and excellent rate capability, as well as a significant increase in tap density. Specifically, the V2O5 microspheres achieve a reversible specific capacity of 414.7 mAh g−1 at 0.1 A g−1, and show a long-term cycling stability retaining 76.5% after 3000 cycles at 2 A g−1. This work provides an efficient route for the synthesis of three-dimensional materials with stable structures, excellent electrochemical performance and high tap density. [ABSTRACT FROM AUTHOR]

[Display omitted] NASICON-structured Ti-based polyanion compounds benefit from a stable structural framework, large ion channels, and fast ion mobility. However, the large radius of potassium and its poor electronic conductivity restrict its use in potassium-ion batteries. Herein, hierarchical mesoporous Mn 0.5 Ti 2 (PO 4) 3 @C microspheres have been successfully synthesized using a simple electrospraying method. These microspheres consist of Mn 0.5 Ti 2 (PO 4) 3 nanoparticles evenly embedded in three-dimensional mesoporous carbon microspheres. The hierarchical mesoporous micro/nanostructure facilitates the rapid insertion and extraction of K+, while the three-dimensional carbon microspheres matrix enhances electrical conductivity and prevents active materials from collapsing during cycling. So the hierarchical mesoporous Mn 0.5 Ti 2 (PO 4) 3 @C microspheres exhibit a high reversible discharge specific capacity (306 mA h g−1 at 20 mA g−1), a notable rate capability (123 mA h g−1 at 5000 mA g−1), and exceptional cycle performance (148 mA h g−1 at 500 mA g−1 after 1000 cycles). The results show that electrosprayed Mn 0.5 Ti 2 (PO 4) 3 @C microspheres are a promising anode for PIBs. [ABSTRACT FROM AUTHOR]

Highlights: A molecular-sieving electrode coating towards low-concentrated aqueous sodium-ion batteries is constructed by applying a composite of NaX zeolite and NaOH-neutralized Nafion. Resulting from a molecular sieving effect of zeolite channels and size-shrunken ionic domains in Nafion, the as-prepared coating layer reject hydrated Na+ ions and allow fast dehydrated Na+ permeance. 200 cycles of Na2MnFe(CN)6//NaTi2(PO4)3 full cells can be achieved in a practically feasible 2 m aqueous electrolyte. Aqueous sodium-ion batteries are known for poor rechargeability because of the competitive water decomposition reactions and the high electrode solubility. Improvements have been reported by salt-concentrated and organic-hybridized electrolyte designs, however, at the expense of cost and safety. Here, we report the prolonged cycling of ASIBs in routine dilute electrolytes by employing artificial electrode coatings consisting of NaX zeolite and NaOH-neutralized perfluorinated sulfonic polymer. The as-formed composite interphase exhibits a molecular-sieving effect jointly played by zeolite channels and size-shrunken ionic domains in the polymer matrix, which enables high rejection of hydrated Na+ ions while allowing fast dehydrated Na+ permeance. Applying this coating to electrode surfaces expands the electrochemical window of a practically feasible 2 mol kg–1 sodium trifluoromethanesulfonate aqueous electrolyte to 2.70 V and affords Na2MnFe(CN)6//NaTi2(PO4)3 full cells with an unprecedented cycling stability of 94.9% capacity retention after 200 cycles at 1 C. Combined with emerging electrolyte modifications, this molecular-sieving interphase brings amplified benefits in long-term operation of ASIBs. [ABSTRACT FROM AUTHOR]

Numerous endeavors have been dedicated to the development of composite polymer electrolyte (CPE) membranes for all-solid-state batteries (SSBs). However, insufficient ionic conductivity and mechanical properties still pose great challenges in practical applications. In this study, a flexible composite electrolyte membrane (FCPE) with fast ion transport channels was prepared using a phase conversion process combined with in situ polymerization. The polyvinylidene fluoride-hexafluoro propylene (PVDF-HFP) polymer matrix incorporated with lithium lanthanum zirconate (LLZTO) formed a 3D net-like structure, and the in situ polymerized polyvinyl ethylene carbonate (PVEC) enhanced the interface connection. This 3D network, with multiple rapid pathways for Li+ that effectively control Li+ flux, led to uniform lithium deposition. Moreover, the symmetrical lithium cells that used FCPE exhibited high stability after 1200 h of cycling at 0.1 mA cm−2. Specifically, all-solid-state lithium batteries coupled with LiFePO4 cathodes can stably cycle for over 100 cycles at room temperature with high Coulombic efficiencies. Furthermore, after 100 cycles, the infrared spectrum shows that the structure of FCPE remains stable. This work demonstrates a novel insight for designing a flexible composite electrolyte for highly safe SSBs. [ABSTRACT FROM AUTHOR]

[Display omitted] • Hard carbon in the PC/EC-based electrolyte can achieve excellent cycle performance and rate performance for sodium-ion batteries. • For the first time, the differences of the ion solvation/desolvation behavior in the electrolytes are proposed to uncover the underlying mechanisms of the distinct electrochemical performance of HC in the PC/EC-based electrolyte and the PC-based electrolyte. • A SEI film with a higher percentage of organic composition is formed in the PC/EC-based electrolyte. • The PC/EC-based electrolyte exhibits a faster ion desolvation process compared to the PC-based electrolyte. Although hard carbon in propylene carbonate / ethylene carbonate (PC/EC)–based electrolytes possesses favorable electrochemical characteristics in rechargeable sodium–ion batteries, the underlying mechanism is still vague. Numerous hypotheses have been proposed to solve the puzzle, but none of them have satisfactorily unraveled the reason at the molecular–level. In this study, we firstly attempted to address this mystery through a profound insight into the disparity of the ion solvation/desolvation behavior in electrolyte. Combining the results of density functional theory (DFT) calculations and experiments, the work explains that compared to the sole PC–based electrolyte, Na+–EC 4 molecules in the PC/EC–based electrolyte preferentially undergo reduction and contribute to the emergence of a more stable protective film on the surface of hard carbon, leading to the preferable durability and rate capability of the cell. Nevertheless, applying the ion solvation/desolvation model, it also reveals that Na+–(solvent) n molecules in the PC/EC–based electrolyte can achieve faster Na+ desolvation processes than in the PC–based electrolyte alone, contributing to the enhancement of charge transfer kinetics. This research holds great importance in uncovering the possible mechanism of the remarkable electrochemical– properties of hard carbon in PC/EC–based electrolytes, and advancing its practical utilization in future sodium–ion batteries. [ABSTRACT FROM AUTHOR]

[Display omitted] Novel structural designs for metal organic frameworks (MOFs) are expected to improve ion-transport behavior in composite solid electrolytes. Herein, upper-dimensional MIL-53(Al) nanofibers (MNFs, MIL-53 belongs to the MIL (Material Institute Lavoisier) group) with flower-like nanoflake structures have been designed and constructed via modified hydrothermal coordination. The optimized MNFs with high surface area and porosity can form abundant interfaces with poly(ethylene oxide) (PEO) matrix. The plasticization of MNFs to the PEO matrix will facilitate segmental movement of PEO chains to facilitate Li+ conduction. The unsaturated open metal centers of MNFs can effectively capture bis(trifluoromethanesulfonyl)imide anions (TFSI−) to deliver more free lithium ions for transfer. Moreover, the upper-dimensional nanofiber structure endows lithium ions with a long-range and consecutive transport pathway. The obtained composite solid electrolyte (MNFs@PEO) presents a high ionic conductivity of 4.1 × 10−4 S cm−1 and a great Li+ transference number of 0.4 at 60 °C. The electrolyte also exhibits a stable Li plating/stripping behavior over 1000 h at 0.1 mA cm−1 with inhibited Li dendrite growth. Furthermore, the Li/LiFePO 4 and Li/LiNi 0.8 Mn 0.1 Co 0.1 O 2 batteries with MNFs@PEO as electrolytes both display great cycling stabilities with high-capacity retention, indicating their potential applications in lithium metal batteries. The study will put forward new inspirations for designing advanced MOF-based composite solid electrolytes. [ABSTRACT FROM AUTHOR]

The CuO anode prepared by the traditional slurry coating method still suffers from limited lithium-ion transport kinetics due to the long diffusion lengths and tortuous transport paths resulting from the addition of conductive agents and binders. In this study, we have prepared the integrated CuO@Cu electrode with the porous CuO nanosheets in situ vertically grown on Cu current collector using a chemical etching method. The integrated electrode design improves the electrical conductivity of the electrode, and the porous nanosheets increase the contact area of the electrolyte and buffer the volume variation of CuO during cycling. Moreover, the vertically grown CuO nanosheets can shorten the lithium ion diffusion path and reduce the tortuosity of lithium ion transport pathways, thus realizing fast lithium ion storage kinetics. While the slurry coating CuO powder electrode shows a capacity of 13.3 mAh g−1 at 20 A g−1, our integrated CuO@Cu electrode still delivers a capacity of 181.6 mAh g−1 at 20 A g−1. This study demonstrates that rational structural design can significantly improve Li-ion storage kinetics. [ABSTRACT FROM AUTHOR]

The phenol–formaldehyde resin (PF) coating regulates Zn ion transfer and interfacial behavior in AZIBs through the dual effect of fast desolvation and ion confinement, thus achieving stable zinc metal anodes. [Display omitted] • PF coating anodes were constructed to regulate the deposition of Zn ions. • Zn@PF anodes has the dual effect of fast desolvation and ion confinement. • Hydroxyl group in PF can promote the desolvation of [Zn(H 2 O) 6 ]2+, thus reducing side reactions. • The pore structure of PF provides ion confinement to uniform ions flux. • Zn@PF||MnO 2 cell can be stably cycled for 1500 cycles at 1.5 A/g. Aqueous Zn ion batteries (AZIBs) are considered to be highly promising rechargeable secondary batteries. However, the growth of zinc dendrites and irreversible side reactions hinder its further application. In this paper, an artificial interfacial protective layer of phenol–formaldehyde resin (PF) was constructed to achieve high-performance zinc anode. There is a strong interaction between hydroxyl groups in PF and Zn ions. This interaction modulates the solvation sheath of Zn ions and promotes the desolvation of [Zn(H 2 O) 6 ]2+, which reduces the side reactions induced by reactive H 2 O. Furthermore, the pore structure of PF provides ion-confinement effect to regulate the Zn ions flux, thus reducing the growth of dendrites caused by inhomogeneous deposition. Thus, the PF coating has the dual effect of fast desolvation and ion confinement, which is beneficial to the uniform Zn ions deposition and achieves highly stable zinc anodes. Consequently, the Zn@PF||MnO 2 full cell can be stably cycled for 1500 cycles at 1.5 A/g and the capacity retention remains 82.4 %. This method provides a convenient and practical approach to tackle the problems of zinc anodes, and establishes the foundation for their further application. [ABSTRACT FROM AUTHOR]

Hard carbon, which features recyclability, low costs, and environmental friendliness, is an attractive anode material for K+ storage. Nevertheless, the state-of-the-art hard carbon is still unsatisfactory due to its poor multiplication performance and unclear energy storage mechanism. In this study, a one-pot carbonisation method using coconut solid waste biomass is applied to obtain high-performance hard-carbon (CHC) anode materials. The microstructure and electrochemical properties of the CHC are investigated at different carbonisation temperatures (1100–1500 °C). The CHC materials prepared at 1300 °C (CHC1300) have a high capacity of 265.8 mAh g−1 at a current density of 25 mA g−1 and a superior cyclability of 1000 cycles at 1.0 A g−1 with a capacity retention of 96.6%. This approach, referred to as the "biomass-to-application" strategy, holds promise for advancing the development of cost-effective and sustainable KIBs. [ABSTRACT FROM AUTHOR]

Ion transport in crystalline solids is an essential process for many electrochemical energy converters such as solid‐state batteries and fuel cells. Empirical data have shown that ion transport in crystal lattices obeys the Meyer‐Neldel Rule (MNR). For similar, closely related materials, when the material properties are changed by doping or by strain, the measured ionic conductivities showing different activation energies intersect on the Arrhenius plot, at an isokinetic temperature. Therefore, the isokinetic temperature is a critical parameter for improving the ionic conductivity. However, a comprehensive understanding of the fundamental mechanism of MNR in ion transport is lacking. Here the physical significance and applicability of MNR is discussed, that is, of activation entropy‐enthalpy compensation, in crystalline fast ionic conductors, and the methods for determining the isokinetic temperature. Lattice vibrations provide the excitation energy for the ions to overcome the activation barrier. The multi‐excitation entropy model suggests that isokinetic temperature can be tuned by modulating the excitation phonon frequency. The relationship between isokinetic temperature and isokinetic prefactor can provide information concerning conductivity mechanisms. The need to effectively determine the isokinetic temperature for accelerating the design of new fast ionic conductors with high conductivity is highlighted. [ABSTRACT FROM AUTHOR]

Aqueous zinc-ion batteries (ZIBs) have significant potential for large energy storage systems because of their high energy density, cost-effectiveness and environmental friendliness. However, the limited voltage window, poor reaction kinetics and structural instability of cathode materials are current bottlenecks which contain the further development of ZIBs. In this work, we rationally design a Ni-doped V2O5@3D Ni core/shell composite on a carbon cloth electrode (Ni-V2O5@3D Ni@CC) by growing Ni-V2O5 on free-standing 3D Ni metal nanonets for high-voltage and high-capacity ZIBs. Impressively, embedded Ni doping increases the interlayer spacing of V2O5, extending the working voltage and improving the zinc-ion (Zn302+) reaction kinetics of the cathode materials; at the same time, the 3D structure, with its high specific surface area and superior electronic conductivity, aids in fast Zn302+ transport. Consequently, the as-designed Ni-V2O5@3D Ni@CC cathodes can operate within a wide voltage window from 0.3 to 1.8 V vs. Zn30/Zn302+ and deliver a high capacity of 270 mAh g−1 (~1050 mAh cm−3) at a high current density of 0.8 A g−1. In addition, reversible Zn2+ (de)incorporation reaction mechanisms in the Ni-V2O5@3D Ni@CC cathodes are investigated through multiple characterization methods (SEM, TEM, XRD, XPS, etc.). As a result, we achieved significant progress toward practical applications of ZIBs. [ABSTRACT FROM AUTHOR]

Herein, the effects of the precursor solution's acidity level on the crystal structure, morphology, nucleation, and growth of WO3·nH2O and WO3 nanostructures are reported. Structural investigations on WO3·nH2O using X-ray diffraction and Fourier–transform infrared spectroscopy confirm that the quantity of hydrate groups increases due to the interaction between H+ and water molecules with increasing HCl volume. Surface analysis results support our claim that the evolution of grain size, surface roughness, and growth direction on WO3·nH2O and WO3 nanostructures rely on the precursor solution's pH value. Consequently, the photocurrent density of a WO3 photoanode using a HCl-5 mL sample achieves the best results with 0.9 mA/cm2 at 1.23 V vs. a reversible hydrogen electrode (RHE). We suggest that the improved photocurrent density of the HCl-5 mL sample is due to the efficient light absorption from the densely grown WO3 nanoplates on a substrate and that its excellent charge transport kinetics originate from the large surface area, low charge transfer resistance, and fast ion diffusion through the photoanode/electrolyte interface. [ABSTRACT FROM AUTHOR]

Li metal batteries using Li metal as negative electrode and LiNi1-x-yMnxCoyO2 as positive electrode represent the next generation high-energy batteries. A major challenge facing these batteries is finding electrolytes capable of forming good interphases. Conventionally, electrolyte is fluorinated to generate anion-derived LiF-rich interphases. However, their low ionic conductivities forbid fast-charging. Here, we use CsNO3 as a dual-functional additive to form stable interphases on both electrodes. Such strategy allows the use of 1,2-dimethoxyethane as the single solvent, promising superior ion transport and fast charging. LiNi1-x-yMnxCoyO2 is protected by the nitrate-derived species. On the Li metal side, large Cs+ has weak interactions with the solvent, leading to presence of anions in the solvation sheath and an anion-derived interphase. The interphase is surprisingly dominated by cesium bis(fluorosulfonyl)imide, a component not reported before. Its presence suggests that Cs+ is doing more than just electrostatic shielding as commonly believed. The interphase is free of LiF but still promises high performance as cells with high LiNi0.8Mn0.1Co0.1O2 loading (21 mg/cm2) and low N/P ratio (~2) can be cycled at 2C (~8 mA/cm2) with above 80% capacity retention after 200 cycles. These results suggest the role of LiF and Cs-containing additives need to be revisited. Fluorinated interphases are often pursued as a design strategy for Li metal batteries. In contrast, here the authors show that an electrolyte with a non-fluorinated solvent and CsNO3 additive results in an LiF-free but inorganic-rich interphase that enables fast-charging of Li metal batteries. [ABSTRACT FROM AUTHOR]

Regulating S doping sites in mesoporous carbon spheres is achieved by annealing with selected precursors. The experimental and theoretical results demonstrate that S doping between the carbon layers enlarges interlayer spacing and facilitates potassium ion adsorption, which is favorable for fast potassium ion storage. [Display omitted] • Sulfur-doped mesoporous carbon spheres with abundant internal surfaces are synthesized. • The sulfur doping sites are controlled by the sulfurization of different precursors. • The optimized sample shows excellent rate capability for potassium storage. • The good electrochemical performance is ascribed to the controlled sulfur doping sites. Mesoporous carbon spheres (MCSs) show great potential for using as high-performance anodes in potassium-ion batteries (PIBs). Design and synthesis of MCSs with suitable multiscale structures and heteroatom doping or co-doping in MCSs are successfully employed to optimize the ion and electron transportation, however, it is still a challenge to explore MCS-based anodes with satisfactory potassium storage performance. In this work, we report novel S-doped MCS samples with abundant internal surfaces for potassium storage. The S doping sites are controlled during the synthesis, and the effect of different doping sites on the potassium storage is systematically studied. It is found that S doping between the carbon layers enlarges interlayer spacing and facilitates potassium ion adsorption. Consequently, the optimized sample shows an excellent rate capability of 144 mAh/g at 5.0 A/g, and a high reversible specific capacity of 325 mAh/g after 100 cycles at 0.1 A/g with a capacity retention of 91.2%. The important role of element doping sites on ion adsorption and ion storage performance is confirmed by theoretical investigations. Controlling the doping sites in MCSs provides a new approach to designing high-performance electrodes for energy storage and conversion applications. [ABSTRACT FROM AUTHOR]

(1) Background: Radioprotective agents have garnered considerable interest due to their prospective applications in radiotherapy, public health medicine, and situations of large-scale accidental radiation exposure or impending radiological emergencies. Cystamine, an organic diamino–disulfide compound, is recognized for its radiation-protective and antioxidant properties. This study aims to utilize the aqueous ferrous sulfate (Fricke) dosimeter to measure the free-radical scavenging capabilities of cystamine during irradiation by fast carbon ions. This analysis spans an energy range from 6 to 500 MeV per nucleon, which correlates with "linear energy transfer" (LET) values ranging from approximately 248 keV/μm down to 9.3 keV/μm. (2) Methods: Monte Carlo track chemistry calculations were used to simulate the radiation-induced chemistry of aerated Fricke–cystamine solutions across a broad spectrum of cystamine concentrations, ranging from 10−6 to 1 M. (3) Results: In irradiated Fricke solutions containing cystamine, cystamine is observed to hinder the oxidation of Fe2+ ions, an effect triggered by oxidizing agents from the radiolysis of acidic water, resulting in reduced Fe3+ ion production. Our simulations, conducted both with and without accounting for the multiple ionization of water, confirm cystamine's ability to capture free radicals, highlighting its strong antioxidant properties. Aligning with prior research, our simulations also indicate that the protective and antioxidant efficiency of cystamine diminishes with increasing LET of the radiation. This result can be attributed to the changes in the geometry of the track structures when transitioning from lower to higher LETs. (4) Conclusions: If we can apply these fundamental research findings to biological systems at a physiological pH, the use of cystamine alongside carbon-ion hadrontherapy could present a promising approach to further improve the therapeutic ratio in cancer treatments. [ABSTRACT FROM AUTHOR]

Ion transport plays an important role in various biological processes because of the ability of ions to move rapidly in biological ion channel‐confined spaces. For example, rapid proton transport in ATPases is attributed to confined channel spaces and conjugated sites. According to molecular dynamics simulations, the confined spaces and conjugated sites in nanochannels can enhance ion transport. Herein, it is demonstrated that the ATPase‐like structures of sulfonic acid‐modified covalent organic framework nanochannels, which promote the formation of highly ordered and continuous water molecular chains and confined spaces, can support ion (H+, Li+, Na+, and K+) transport rates that are an order of magnitude higher than those of bulk water. The ion transport rates in the nanochannel are superior to those in other artificial channels. Moreover, the selectivity of cations in the nanochannel is evaluated using the diffusion potential with a concentration gradient. The simulations and experimental results demonstrate that confined spaces and conjugated sites are crucial for efficient ion transport in nanochannels modified by sulfonic acid groups as cation conductor materials. [ABSTRACT FROM AUTHOR]

2LiX-GaF3 (X = Cl, Br, I) electrolytes offer favorable features for solid-state batteries: mechanical pliability and high conductivities. However, understanding the origin of fast ion transport in 2LiX-GaF3 has been challenging. The ionic conductivity order of 2LiCl-GaF3 (3.20 mS/cm) > 2LiBr-GaF3 (0.84 mS/cm) > 2LiI-GaF3 (0.03 mS/cm) contradicts binary LiCl (10-12 S/cm) < LiBr (10-10 S/cm) < LiI (10-7 S/cm). Using multinuclear 7Li, 71Ga, 19F solid-state nuclear magnetic resonance and density functional theory simulations, we found that Ga(F,X)n polyanions boost Li+-ion transport by weakening Li+-X- interactions via charge clustering. In 2LiBr-GaF3 and 2LiIGaF3, Ga-X coordination is reduced with decreased F participation, compared to 2LiCl-GaF3. These insights will inform electrolyte design based on charge clustering, applicable to various ion conductors. This strategy could prove effective for producing highly conductive multivalent cation conductors such as Ca2+ and Mg2+, as charge clustering of carboxylates in proteins is found to decrease their binding to Ca2+ and Mg2+. [ABSTRACT FROM AUTHOR]

The reference ion cyclotron resonance frequency (ICRF) heating schemes for ITER deuterium–tritium (D-T) plasmas at the full magnetic field of 5.3 T are second harmonic heating of T and 3He minority heating. The wave-particle resonance location for these schemes coincide and are central at a wave frequency of 53 MHz at 5.3 T. Experiments have been carried out in the second major D-T campaign (DTE2) at JET, and in its prior D campaigns, to integrate these ICRF scenarios in JET high-performance plasmas and to compare their performance with the commonly used hydrogen (H) minority heating. In 50:50 D:T plasmas, up to 35% and 5% larger fusion power and diamagnetic energy content, respectively, were obtained with second harmonic heating of T as compared to H minority heating at comparable total input powers and gas injection rates. The core ion temperature was up to 30% and 20% higher with second harmonic T and 3He minority heating, respectively, with respect to H minority heating. These are favourable results for the use of these scenarios in ITER and future fusion reactors. According to modelling, adding ICRF heating to neutral beam injection using D and T beams resulted in a 10%–20% increase of on-axis bulk ion heating in the D-T plasmas due to its localisation in the plasma core. Central power deposition was confirmed with the break-in-slope and fast Fourier transform analysis of ion and electron temperature in response to ICRF modulation. The tail temperature of fast ICRF-accelerated tritons, their enhancement of the fusion yield and time behaviour as measured by an upgraded magnetic proton recoil spectrometer and neutral particle analyser were found in agreement with theoretical predictions. No losses of ICRF-accelerated ions were observed by fast ion detectors, which was as expected given the high plasma density of n e ≈ 7–8 × 1019 m−3 in the main heating phase that limited the formation of ICRF-accelerated fast ion tails. 3He was introduced in the machine by 3He gas injection, and the 3He concentration was measured by a high-resolution optical penning gauge in the sub-divertor region. The DTE2 experiments with 3He minority heating were carried with a low 3He concentration in the range of 2%–4% given the fact that the highest neutron rates with 3He minority heating in D plasmas were obtained at low 3He concentrations of ∼2%, which also coincided with the highest plasma diamagnetic energy content. In addition to 3He introduced by 3He gas injection, an intrinsic concentration of 3He of the order of 0.2%–0.4% was measured in D-T plasmas before 3He was introduced in the device, which is attributed to the radioactive decay of tritium to 3He. According to modelling, even such low intrinsic concentrations of 3He lead to significant changes in ICRF power partitioning during second harmonic heating of T due to absorption of up to 30% of the wave power by 3He. [ABSTRACT FROM AUTHOR]

In JET deuterium-tritium (D-T) plasmas, the fusion power is produced through thermonuclear reactions and reactions between thermal ions and fast particles generated by neutral beam injection (NBI) heating or accelerated by electromagnetic wave heating in the ion cyclotron range of frequencies (ICRFs). To complement the experiments with 50/50 D/T mixtures maximizing thermonuclear reactivity, a scenario with dominant non-thermal reactivity has been developed and successfully demonstrated during the second JET deuterium-tritium campaign DTE2, as it was predicted to generate the highest fusion power in JET with a Be/W wall. It was performed in a 15/85 D/T mixture with pure D-NBI heating combined with ICRF heating at the fundamental deuterium resonance. In steady plasma conditions, a record 59 MJ of fusion energy has been achieved in a single pulse, of which 50.5 MJ were produced in a 5 s time window (P fus = 10.1 MW) with average Q = 0.33, confirming predictive modelling in preparation of the experiment. The highest fusion power in these experiments, P fus = 12.5 MW with average Q = 0.38, was achieved over a shorter 2 s time window, with the period of sustainment limited by high-Z impurity accumulation. This scenario provides unique data for the validation of physics-based models used to predict D-T fusion power. [ABSTRACT FROM AUTHOR]

[Display omitted] Development of multitudinous heteroatoms co-doped carbon nanomaterials with pleasurable electrochemical behavior for sodium ion batteries is still an enormous challenge. Herein, high dispersion cobalt nanodots encapsulating into N, P, S tri-doped hexapod carbon (H-Co@NPSC) have been victoriously synthesized via H-ZIF67@polymer template strategy with using poly (hexachlorocyclophos-phazene and 4,4′-sulfonyldiphenol) as both carbon source and N, P, S multiple heteroatom doping sources. The uniform distribution of cobalt nanodots and the Co-N bonds are conducive to form a high conductive network, which synergistically increase a lot adsorption sites and lessens the diffusion energy barrier, thereby improving the fast Na+ ions diffusion kinetics. Consequently, H-Co@NPSC delivers the reversible capacity of 311.1 mAh g−1 at 1 A g−1 after 450 cycles with 70% capacity storage rate, while obtains the capacity of 237.1 mAh g- 1 after 200 cycles at the elevated current densities of 5 A g−1 as an excellent anode material for SIBs. These interesting results pave a generous avenue for the exploitation of promising carbon anode materials for Na+ storage. [ABSTRACT FROM AUTHOR]

Two‐dimensional (2D) transition metal carbonitrides/nitrides (MXene) materials have proven to be promising alternatives as novel capacitor‐type electrodes for aqueous Zn‐ion hybrid microsupercapacitors (ZHMSCs). However, during self‐assembly processes, serious restacking between 2D MXene nanosheets induced by strong van der Waals forces makes ion transport channels narrow within the compact MXene film electrodes, which would result in poor energy output of ZHMSCs. Herein, interlayer transport channel engineering is designed by intercalating bacterial cellulose (BC) between MXene interlayers to develop MXene/BC electrodes with fast ion transport channels in contrast to pure MXene electrodes. Benefiting from fast anion intercalation/deintercalation on MXene/BC capacitor‐type cathode and reversible Zn stripping/plating on Zn foil anode, the fabricated ZHMSCs exhibit wide working potential windows (1.36 V), high areal capacitance (404 mF cm−2), and landmark areal energy density (94 µWh cm−2 at 1 mA cm−2). The areal capacitance and energy density of the developed ZHMSCs are much higher than those of the ZHMSCs based on pure MXene capacitor‐type cathode (239 mF cm−2/57 µWh cm−2 at 1 mA cm−2). Besides, the developed ZHMSCs can perform more than 10,000 cycles, showing outstanding capacity retention. In general, our work provides a novel strategy to break through the performance bottlenecks afflicting MXene‐based ZHMSCs. [ABSTRACT FROM AUTHOR]

Through the sacrificial template manners, series of sphere-like FeSe 2 @C samples are successfully prepared, displaying uniform carbon coating and interfacial chemical Fe O C bonds. Utilized as SIBs anodes, the optimized sample displays considerable capacity, which could reach up to 462.9 mAh g−1 with 88.75% coulombic efficiency at 1.0 A g−1. [Display omitted] Due to their low cost and high stability, sodium-ion batteries have been increasingly studied. However, their further development is limited by the relative energy density, resulting in the search for high-capacity anodes. FeSe 2 displays high conductivity and capacity but still suffers from sluggish kinetics and serious volume expansion. Herein, through sacrificial template methods, a series of sphere-like FeSe 2 -carbon composites are successfully prepared, displaying uniform carbon coatings and interfacial chemical Fe O C bonds. Moreover, benefiting from the unique traits of precursor and acid treatment, rich structural voids are prepared, effectively alleviating volume expansion. Utilized as anodes of sodium-ion batteries, the optimized sample displays considerable capacity, achieving 462.9 mAh g−1, with 88.75% coulombic efficiency at 1.0 A g−1. Even at 5.0 A g−1, their capacity can be kept at approximately 318.8 mAh g−1, while the stable cycling can be prolonged to 200 cycles above. Supported by the detailed kinetic analysis, it can be noted that the existing chemical bonds facilitate the fast shuttling of ions at the interface, and the enhanced surface/near-surface properties are further vitrified. Given this, the work is expected to offer valuable insights for the rational design of metal-based samples toward advanced sodium-storage materials. [ABSTRACT FROM AUTHOR]

Porous materials occupy an important place among the materials of electronic equipment. Nanopores, which are obtained by ion irradiation of materials, have a complex internal structure that depends on the interaction of fast ions with the substance. Obtaining such structures is important, in particular, in the manufacture of biosensor devices based on them. The most effective methods of studying their properties are computer simulations. However, effective computer models of track structures, necessary for the development and improvement of modern biosensors, are not being created actively enough. The approach proposed here involves a detailed study of the interaction of ion flows with the inner surface of the nanotrack. This approach takes into account the structural features of the inner surface of the track as well as the role of adsorption and scattering centers and other local centers. In the existing approaches, the processes mentioned above are mainly described phenomenologically, which does not indicate the ways of modifying the characteristics of the material that is necessary for the device improvement. [ABSTRACT FROM AUTHOR]

The templating method holds great promise for fabricating surface nanopatterns. To enhance the manufacturing capabilities of complex surface nanopatterns, it is important to explore new modes of the templates beyond their conventional masking and molding modes. Here, we employed the metal-organic framework (MOF) microparticles assembled monolayer films as templates for metal electrodeposition and revealed a previously unidentified guiding growth mode enabling the precise growth of metallic films exclusively underneath the MOF microparticles. The guiding growth mode was induced by the fast ion transportation within the nanochannels of the MOF templates. The MOF template could be repeatedly used, allowing for the creation of identical metallic surface nanopatterns for multiple times on different substrates. The MOF template-guided electrochemical growth mode provided a robust route towards cost-effective fabrication of complex metallic surface nanopatterns with promising applications in metamaterials, plasmonics, and surface-enhanced Raman spectroscopy (SERS) sensing fields. Templating method holds great promise for fabricating surface nanopatterns. Here authors present a guiding growth mode using metal-organic framework microparticles as templates during metal electrodeposition, where metals exclusively grow underneath the microparticles. [ABSTRACT FROM AUTHOR]

[Display omitted] Aqueous Zn-ion battery is expected to become a substitute for Li-ion battery due to its inherent safety, low cost, and environmental friendliness. Dendrite growth and side reaction problems during electroplating lead to its low Coulombic efficiency and unsatisfactory life, which greatly limits its practical application. Here, we propose a dual-salts hybrid electrolyte, which alleviates the above issues by mixing Zn(OTf) 2 to ZnSO 4 solution. Extensive tests and MD simulations have shown that the dual-salts hybrid electrolyte can regulate the solvation structure of Zn2+, facilitating uniform Zn deposition, and inhibiting side reactions and dendrite growth. Hence, the dual-salts hybrid electrolyte exhibits good reversibility in Zn//Zn batteries, which can provide a lifetime of more than 880 h at 1 mA cm−2 and 1 mAh cm−2. Moreover, the average Coulombic efficiency of Zn//Cu cells in hybrid system can reach 98.2% after 520 h, much better than that of 90.7% in pure ZnSO 4 electrolyte and 92.0% in pure Zn(OTf) 2 electrolyte. Benefiting from the fast ion exchange rate and high ion conductivity, Zn-ion hybrid capacitor in hybrid electrolyte also displays excellent stability and capacitive performance. This effective strategy for dual-salts hybrid electrolytes provides a promising direction for designing aqueous electrolytes for Zn-ion batteries. [ABSTRACT FROM AUTHOR]

[Display omitted] Nickel-based sulfides are considered promising materials for sodium-ion batteries (SIBs) anodes due to their abundant resources and attractive theoretical capacity. However, their application is limited by slow diffusion kinetics and severe volume changes during cycling. Herein, we demonstrate a facile strategy for the synthesis of nitrogen-doped reduced graphene oxide (N -rGO) wrapped Ni 3 S 2 nanocrystals composites (Ni 3 S 2 - N -rGO-700 °C) through the cubic NiS 2 precursor under high temperature (700 ℃). Benefitting from the variation in crystal phase structure and robust coupling effect between the Ni 3 S 2 nanocrystals and N -rGO matrix, the Ni 3 S 2 - N -rGO-700 °C exhibits enhanced conductivity, fast ion diffusion kinetics and outstanding structural stability. As a result, the Ni 3 S 2 - N -rGO-700 °C delivers excellent rate capability (345.17 mAh g−1 at a high current density of 5 A g−1) and long-term cyclic stability over 400 cycles at 2 A g−1 with a high reversible capacity of 377 mAh g−1 when evaluated as anodes for SIBs. This study open a promising avenue to realize advanced metal sulfide materials with desirable electrochemical activity and stability for energy storage applications. [ABSTRACT FROM AUTHOR]

The VO 2 nanobelts with oxygen vacancies that were dispersed on interconnected nitrogen doped carbon nanosheets were fabricated (VO 2-x /NC), which exhibits impressive performance in sodium ion battery and sodium ion hybrid capacitors. [Display omitted] • The VO 2 nanobelts with oxygen vacancies are dispersed on interconnected ultrathin NC nanosheets (VO 2-x /NC). • VO 2-x /NC exhibits comprehensive performance including high storage capacity, fast ion/electron diffusion kinetics and ultralong cycle life in SIBs. • DFT indicates that the incorporating of oxygen vacancies provides extra surface capacitance and electronic conductivity, thus favoring fast kinetics. • SIHCs exhibits high energy/power density with ultralong lifespan and practical applications. Developing anode materials with high reversible capacity, fast redox kinetics, and stable cycling life for Na+ storage remains a great challenge. Herein, the VO 2 nanobelts with oxygen vacancies supported on nitrogen-doped carbon nanosheets (VO 2-x /NC) were developed. Benefitting from the enhanced electrical conductivity, the accelerated kinetics, the increased active sites as well as the constructed 2D heterostructure, the VO 2-x /NC delivered extraordinary Na+ storage performance in half/full battery. Theoretical calculations (DFT) demonstrated that oxygen vacancies could regulate the adsorption ability for Na+, enhance electronic conductivity, as well as achieve rapid and reversible Na+ adsorption/desorption. The VO 2-x /NC exhibited high Na+ storage capacity of 270 mAh g−1 at 0.2 A g−1, and impressive cyclic stability with 258 mAh g−1 after 1800 cycles at 10 A g−1. The assembled sodium-ion hybrid capacitors (SIHCs) could achieve maximum energy density/power output of 122 Wh kg−1/9985 W kg−1, ultralong cycling life with 88.4% capacity retention after 25,000 cycles at 2 A g−1, and practical applications (55 LEDs could be actuated for 10 min), promising to be utilized in a practicable Na+ storage. [ABSTRACT FROM AUTHOR]

In situ formation of a stable interphase layer on zinc surface is an effective solution to suppress dendrite growth. However, the fast transport of bivalent Zn-ions within the solid interlayer remains very challenging. Herein, we engineer the SEI components and enable superior kinetics of Zn metal batteries under harsh conditions through regulating the sequence of interfacial chemical reaction. With the differences in chemical reactivity of trimethyl phosphate co-solvent and trifluoromethanesulfonate anions in the Zn2+-solvation shell, Zn3(PO4)2 and ZnF2 are successively generated on Zn metal surface to form a gradient ZnF2–Zn3(PO4)2 interphase. Mechanistic studies reveal the outer ZnF2 facilitates Zn2+ desolvation and inner Zn3(PO4)2 serves as channels for fast Zn2+ transport, contributing to long-term cycling at subzero temperatures. Impressively, the gradient SEI enables a high lifespan over 7000 hours in Zn symmetric cell and a capacity retention of 86.1% after 12000 cycles in Zn–KVOH full cell at –50 °C. Zinc batteries have received intense attentions but suffer from inferior low-temperature performance. Here, the authors constructed a gradient phosphatized interphase in situ on zinc surface to accelerate zinc-ion desolvation and transport, greatly enhancing the cycling performance at subzero temperatures. [ABSTRACT FROM AUTHOR]

Neutral beam injection (NBI) systems based on negative hydrogen ion sources—rather than the positive ion sources that have typically been used to date—will be used in the future magnetically confined nuclear fusion experiments to heat the plasma. The collisions between the fast negative ions and neutral background gas result in a significant number of high-energy positive ions being produced in the acceleration area, and for the high-power long-pulse operation of NBI systems, this acceleration of positive ions back to the ion source creates heat load and material sputtering on the source backplate. This difficulty cannot be ignored, with the neutral gas density in the acceleration region having a significant impact on the flux density of the backstreaming positive ions. In the work reported here, the pressure gradient in the acceleration region was estimated using an ionization gauge and a straightforward 1D computation, and it was found that once gas traveled through the acceleration region, the pressure dropped by nearly one order of magnitude, with the largest pressure drop occurring at the plasma grid. The computation also revealed that the pressure drop in the grid gaps was substantially smaller than that in the grid apertures. Highlights: • A simple 1D calculation is used to predict the pressure gradient in a high-power negative ion source accelerator. • The calculation has the primary pressure drop occurring in the aperture, whereas experiments show that it occurs mainly in the grid gaps. • The pressure decreases linearly when the pumping speed is neglected, whereas experiments indicate that it actually decreases exponentially. [ABSTRACT FROM AUTHOR]