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The LiNi 0.8 0 Co 0.15 Al 0.05 O 2-δ (LNCA) electrode exhibits better catalytic activity in low-temperature solid oxide fuel cells (LT-SOFCs). However, LNCA still faces some challenges in commercialization due to poor stability, scarcity of lithium resources, and high costs. Here, Na-doped LNCA electrode not only enriches oxygen vacancies and prolongs long-term stability, but also maintains a layered structure and reduces costs. At 550 °C, under the optimal ratio of L 0.85 Na 0.15 NCA electrode, the maximum power density (MPD) of a single cell reaches 1147 mW cm−2 with an open circuit voltage (OCV) of 1.13 V and a polarization impedance (R p) of 0.21 Ω cm2, which is 30.6% higher than the single cell power (878 mW cm−2) of the Na-undoped LNCA electrode. The cell maintained long-term stability for 108 h at a constant current density of 156.25 mA cm−2 and a voltage of about 0.9 V. The results indicate that Na-doped LNCA is an effective strategy to improve the electrochemical performance of LNCA and long-term stability of cell. [Display omitted] • The crystal structure of Na-doped NCAL electrode is more stable. • The L 0.85 Na 0.15 NCA electrode can generate more oxygen vacancies. • The MPD of the L 0.85 Na 0.15 NCA symmetrical electrode reached 1147 mW cm−2 at 550 °C. • The L 0.85 Na 0.15 NCA electrode remained stable at 550 °C for 108 h. [ABSTRACT FROM AUTHOR]

Using symmetrical electrodes with the same material compositions can simplify the manufacturing process, reduce cost, and enhance the stability and reliability of solid oxide cells. Herein, we report for the first time the potential application of the La 0.3 Sr 0.7 Fe 0.7 Cr 0.3 O 3-δ (LSFC) perovskite as a symmetrical electrode for reversible protonic ceramic cells (RPCCs). The LSFC exhibits robust chemical stability in oxidizing and reducing environments and favorable chemical compatibility with BaZr 0.4 Ce 0.4 Y 0.15 Zn 0.05 O 3-δ electrolyte below 950 °C. Using LSFC as a symmetrical electrode, the electrolyte-supported RPCC delivers a maximum power density of 76 mW cm−2 in fuel cell (FC) mode at 700 °C, and a maximum current density of 30 mA cm−2 in electrolysis cell (EC) mode at 1.5 V; no significant degradation is shown under both FC and EC modes during 100 h continuous operation. The LSFC shows remarkably low polarization resistances (R p) of 0.06 and 0.07 Ω cm2 at 700 °C in dry and wet air, which allows it to be used directly as an air electrode; while it is 3.46 Ω cm2 at 700 °C in 5%H 2 /Ar, which needs to improve its catalytic activity to enhance the overall performance of symmetrical electrode. These results allow us to propose a feasible strategy for applying symmetrical electrodes in RPCCs. [Display omitted] • LSFC is proposed as a symmetrical electrode for reversible protonic ceramic cells. • LSFC has good chemical compatibility with BZCYZ electrolyte below 950 °C. • LSFC shows favorable stability in both oxidizing and reducing environments. • LSFC electrode exhibits remarkably low polarization resistance in dry and wet air. [ABSTRACT FROM AUTHOR]

The thermal expansion coefficient (TEC) mismatch between the cathode and electrolyte presents significant challenge to the thermo-mechanical stability of commercial solid oxide fuel cells (SOFCs). Here a thermal expansion offset composite cathode designated as Ba 0.5 Sr 0.5 FeO 3-δ (BSF)-xNdMnO 3-δ (NM) (x = 0–40 wt%) is developed to address this issue. For the first time, the phase boundary between heterogeneous oxides and the grain size of composite cathode are quantitatively studied with the electron backscatter diffraction (EBSD) technology. For x = 20 wt%, the TEC of cathode decreases by 41 % while the peeling strength of cathode/electrolyte interface increases by 87 %. The highest peak power density (PPD) is achieved for BSF-20NM cathode (1266 mW cm−2 at 650 °C), which is 81 % higher than that for BSF one. Meanwhile, markedly enhanced long-term and thermal cycling stability is obtained. The comprehensive results suggest that both the increased TPB length by enhanced cathode/electrolyte bonding and grain refinement of composite cathode should be responsible for the markedly improved performance and stability. [ABSTRACT FROM AUTHOR]

Protonic ceramic fuel cells (PCFCs), which are based on proton conducting electrolytes, are a class of power generation devices that can efficiently operate at the intermediate (500–700 °C), even low (450 °C) temperatures, but their development is hindered by sluggish cathodic kinetics at reduced temperatures. At the PCFC cathode, the absorbed oxygen molecules react with oxygen vacancies, protons and electrons to generate water and release electrical energy. Thus, the PCFC cathode materials require percolation network for proton, oxide-ion, and electron carriers simultaneously. In this work, we developed a triple ionic-electronic conductor BaCo 0.4 Fe 0.4 Zr 0.15 W 0.05 O 3-δ as a new cathode material for the PCFCs using BaZr 0.1 Ce 0.7 Y 0.1 Yb 0.1 O 3-δ as the electrolyte. Anode supported cells were fabricated and the performances were investigated. Compared with the parent oxide, tungsten doping can significantly improve the electrochemical reduction kinetic of oxygen. The BaCo 0.4 Fe 0.4 Zr 0.15 W 0.05 O 3-δ based PCFC obtained the peak power density of 688 mW ⋅ cm−2 at 600 °C, which is 1.29 time higher than that of BaCo 0.4 Fe 0.4 Zr 0.2 O 3-δ based PCFC (the peak power density of 534 mW ⋅ cm−2 at 600 °C). Moreover, BaCo 0.4 Fe 0.4 Zr 0.15 W 0.05 O 3-δ has a better thermal expansion matching with the electrolyte material BaZr 0.1 Ce 0.7 Y 0.1 Yb 0.1 O 3-δ. [Display omitted] [ABSTRACT FROM AUTHOR]

Alkaline zinc‐iron flow batteries (ZFBs) have recently attracted renewed attention. However, the critical issues with zinc anodes, such as dendrite formation, side reactions, and labile plating or stripping, have yet to be adequately addressed. Here, an attempt is made to overcome these challenges by designing Boron‐doped carbon‐felt (B–CF) electrodes rich in electron‐deficient sites and defects. The fabricated B–CF provides improved adsorption of negatively charged Zn(OH)42−, robust Zn nucleation sites, and lower Zn nucleation and deposition overpotentials, leading to homogeneous Zn deposition morphology. Uniform Zn deposition enables the prevention of undesirable dendrite growth and parasitic reactions. As a result, the constructed alkaline ZFBs achieve a high average Coulombic efficiency of ≈99.85% and energy efficiency of 88% with uniform Zn deposition during 300 cycles (40 mA cm−2). This work expands the understanding of the electrode design strategy for achieving favorable Zn plating/stripping. [ABSTRACT FROM AUTHOR]

The spin state of transition‐metal compounds in lithium‐sulfur batteries (LSBs) significantly impacts the electronic properties and the kinetics of sulfur redox reactions (SRR). However, accurately designing the spin state remains challenging, which is crucial for understanding the structure‐performance relationship and developing high‐performance electrocatalysts. Herein, the CoF2, specifically the Co2+ with 3d7 electrons in a high‐spin state distribution (t2g5eg2), were tailored predictably for the first time through the weak coordination field effect of the F element. Both DFT calculations and experimental results confirm that the spin state of Co2+ transitions from low‐ to high‐spin configurations and strongly interacts with sulfur species through Co−S and Li−F bonds during the SRR process. This interaction weakens the S−S bond, promoting its facile cleavage from both ends while also facilitating the rapid and uniform nucleation of Li2S2/Li2S, thus resulting in LSBs with a capacity of 447.7 mAh g−1 at 10 C rates and stable cycling for 1000 cycles, with an acceptable practical capacity of 585 mAh g−1 at a high sulfur loading mass of 10 mg cm−2. This work achieves rational control of the active Co2+ d electron state through the field effect and enriches the application of spin control to accelerate SRR in LSBs. [ABSTRACT FROM AUTHOR]

Sub‐nanoclusters with ultra‐small particle sizes are particularly significant to create advanced energy storage materials. Herein, Sn sub‐nanoclusters encapsulated in nitrogen‐doped multichannel carbon matrix (denoted as Sn‐SCs@MCNF) are designed by a facile and controllable route as flexible anode for high‐performance potassium ion batteries (PIBs). The uniformly dispersed Sn sub‐nanoclusters in multichannel carbon matrix can be precisely identified, which ensure us to clarify the size influence on the electrochemical performance. The sub‐nanoscale effect of Sn‐SCs@MCNF restrains electrode pulverization and enhances the K+ diffusion kinetics, leading to the superior cycling stability and rate performance. As freestanding anode in PIBs, Sn‐SCs@MCNF manifests superior K+ storage properties, such as exceptional cycling stability (around 331 mAh g−1 after 150 cycles at 100 mA g−1) and rate capability. Especially, the Sn‐SCs@MCNF||KFe[Fe(CN)6] full cell demonstrates impressive reversible capacity of around 167 mAh g−1 at 0.4 A g−1 even after 200 cycles. Theoretical calculations clarify that the ultrafine Sn sub‐nanoclusters are beneficial for electron transfer and contribute to the lower energy barriers of the intermediates, thereby resulting in promising electrochemical performance. Comprehensive investigation for the intrinsic K+ storage process of Sn‐SCs@MCNF is revealed by in situ analysis. This work provides vital guidance to design sub‐nanoscale functional materials for high‐performance energy‐storage devices. [ABSTRACT FROM AUTHOR]

Chemical self‐recharging zinc ion batteries (ZIBs), which are capable of auto‐recharging in ambient air, are promising in self‐powered battery systems. Nevertheless, the exclusive reliance on chemical energy from oxygen for ZIBs charging often would bring some obstacles in charging efficiency. Herein, we develop photo‐assisted chemical self‐recharging aqueous ZIBs with a heterojunction of MoS2/SnO2 cathode, which are favorable to enhancing both the charging and discharging efficiency as well as the chemical self‐charging capabilities under illumination. The photo‐assisted process promotes the electron transfer from MoS2/SnO2 to oxygen, accelerating the occurrence of the oxidation reaction during chemical self‐charging. Furthermore, the electrons within the MoS2/SnO2 cathode exhibit a low transfer impedance under illumination, which is beneficial to reducing the migration barrier of Zn2+ within the cathode and thereby facilitating the uniform inserting of Zn2+ into MoS2/SnO2 cathode during discharging. This photo‐assisted chemical self‐recharging mechanism enables ZIBs to attain a maximum self‐charging potential of 0.95 V within 3 hours, a considerable self‐charging capacity of 202.5 mAh g−1 and excellent cycling performance in a self‐charging mode. This work not only provides a route for optimizing chemical self‐charging energy storage, but also broadens the potential application of aqueous ZIBs. [ABSTRACT FROM AUTHOR]

In the present article, facile and novel synthesis of Cu 2 MnSnS 4 /reduced-graphene (CMTS/rGO) nanocomposites is achieved. X-ray diffraction (XRD), Raman analysis, X-ray photoelectron spectroscopy (XPS) were explored to test the supposed formation. CMTS semiconductors grow within a tetragonal symmetry and rGO crystallize into hexagonal phase. CMTS particle size is very small having dimensions around 10–12 nm and corroborates with the average particle size calculated from the SEM. The TEM micrograph of rGO consists ∼10 nm thick nanosheets. The composite materials exhibit 2D morphology with 17 nm thick rGO nanosheets holding CMTS quantum dots (9 nm). Electronic structure modulations with rGO specify the replication of energy band gaps with experimental agreements. Photocatalytic activity against malachite green (MG) enhances from 74 % (CMTS) to 95 % (CMTS/rGO). In addition, the electrochemical measurements demonstrate the specific capacitance for 10 % CMTS/rGO (870 F/g) is about four times larger than that of pure CMTS (268 F/g). Our results prompt the evidence of possible applications and further research in photocatalysis via graphene reduction. [Display omitted] [ABSTRACT FROM AUTHOR]

As a typical special soil, red clay found in Guizhou Province, China, must be improved before it can be used for projects owing to its high plasticity. As a soil curing agent, the Consolid system is applicable to a wide range of soils, has good improvement effects and a simple operation, and is environmentally friendly. The effects of the dosage and curing age of the Consolid system on the unconfined compressive strength and shrinkage properties of the cured red clay–gravel mixture are studied. The results showed that both these properties of the red clay–gravel mixture were significantly improved by the Consolid System, and the higher the dosage of the Consolid system, the better the improvement effect. The thermal methods of thermogravimetric analysis and differential scanning calorimetry were used to determine that the bound water content was related to the amount of Consolid system admixture. With the increase in the dosage of the Consolid system, the weakly bound water content of red clay appeared to be reduced to different degrees, while the strongly bound water content was reduced to a lesser extent. The reduction in the weakly bound water led to an increase in the molecular gravitational force between the soil particles. This promoted the agglomeration of the soil particles to form a stronger agglomerate structure, thereby enhancing its mechanical properties. The physical phase analysis of cured soils with different amounts of Consolid system admixture was carried out by X-ray diffraction analysis. No chemical reaction occurred during improvement, but the crystal spacing was reduced. This phenomenon could be a factor improving the shrinkage properties. In addition, the shrinkage properties of the soil improved because of the low number of exchangeable cations on the mineral surface, allowing the cured soil to enter a charge equilibrium state quickly. [ABSTRACT FROM AUTHOR]

The Rubik's cube PBA frameworks with infinite structural variations have been obtained by a simple coprecipitation method and exhibits enhanced cycling and rate performance when tested as the anode materials in alkali-ion batteries (LIBs, SIBs, and KIBs). More importantly, the storage mechanism of the Co-Zn PBA frameworks have also been explored by DFT, in-situ XRD, and XPS measurements. [Display omitted] • Successfully synthesized Rubik's Co-M PBAs and explored the storage mechanism of the anode in alkali-metal-ion batteries. PBA frameworks have stood out among metal–organic frameworks because of their easy preparation, excellent stability, porous structures, and rich redox properties. Unfortunately, their non-ideal conductivity and significant volume expansion during cycling prevent more widespread application in alkali-metal-ion (Li+, Na+, and K+) batteries. By changing the type and molar ratio of metal ions, Rubik's PBA frameworks with infinite structural variations were obtained in this study, just like the Rubik's cube undergoes infinite changes during the rotation. X-ray adsorption fine structure measurements have documented the existence and determined the coordination environment of the metal ions in the Rubik's PBA framework. Benefiting from the more stable Rubik's cube structures with diverse composition, enhanced conductivity, and greater adsorption capacity, the obtained Rubik's cubes CoM-PBA anodes, especially CoZn-PBA deliver the enhanced cycling and rate performance in all the alkali-metal-ion batteries. The findings are supported by density functional theory calculations. Ex-situ X-ray photoelectron spectroscopy, and in-situ X-ray diffraction measurements were undertaken to explore the storage mechanism of CoZn-PBA anodes. Our results further demonstrate that the Rubik's cube PBA framework-based materials could be widely applied in the field of alkali-metal-ion batteries. [ABSTRACT FROM AUTHOR]

Lithium‐sulfur batteries are emerging as sustainable replacements for current lithium‐ion batteries. The commercial viability of this novel type of battery is still under debate due to the extensive use of highly reactive lithium‐metal anodes and the complex electrochemistry of the sulfur cathode. In this research, a novel sulfur‐based battery has been proposed that eliminates the need for metallic lithium anodes and other critical raw materials like cobalt and graphite, replacing them with biomass‐derived materials. This approach presents numerous benefits, encompassing ample availability, cost‐effectiveness, safety, and environmental friendliness. In particular, two types of biochar‐based anode electrodes (non‐activated and activated biochar) derived from spent common ivy have been investigated as alternatives to metallic lithium. We compared their structural and electrochemical properties, both of which exhibited good compatibility with the typical electrolytes used in sulfur batteries. Surprisingly, while steam activation results in an increased specific surface area, the non‐activated ivy biochar demonstrates better performance than the activated biochar, achieving a stable capacity of 400 mA h g−1 at 0.1 A g−1 and a long lifespan (>400 cycles at 0.5 A g−1). Our results demonstrate that the presence of heteroatoms, such as oxygen and nitrogen positively affects the capacity and cycling performance of the electrodes. This led to increased d‐spacing in the graphitic layer, a strong interaction with the solid electrolyte interphase layer, and improved ion transportation. Finally, the non‐activated biochar was successfully coupled with a sulfur cathode to fabricate lithium‐metal‐free sulfur batteries, delivering a specific energy density of ~600 Wh kg−1. [ABSTRACT FROM AUTHOR]

Ba0.9Sr0.1Ce0.4Zr0.6−xYbxO3−δ(x = 0.05, 0.1, 0.15, 0.2) proton-conducting electrolyte powders were synthesized by the nitrate combustion method. The effects of co-doping of Sr and Yb on the phase composition and electrochemical performance were studied. X-ray diffraction (XRD) results indicate that Sr and Yb were successfully doped into the lattice of BaCe0.4Zr0.6O3, forming a single perovskite phase. The AC impedance technique was used to investigate the total conductivity of the materials under air and water vapor atmospheres at 400–800°C. The results show that BSCZY20 demonstrated the highest electrical conductivity of 0.033 S cm−1 at 800°C in water vapor. This suggests that the co-doping strategy can effectively enhance the conductivity of BaCe0.4Zr0.6O3 proton-conducting material, which provides valuable insight for the development of high-performance proton-conducting solid oxide fuel cells. [ABSTRACT FROM AUTHOR]

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The discharge capacities and rate capability of TiNb2O7 powders were enhanced through the additional postreduction treatment. X‐ray photoelectron spectroscopy and electron paramagnetic resonance results confirmed the formation of oxygen vacancies in TiNb2O7 powders after a reduction treatment. The appearance of oxygen vacancies in TiNb2O7 powders formed the impurity level in the forbidden gap and decreased the bandgap values of TiNb2O7. Compared with the pristine TiNb2O7 powders, when TiNb2O7 powders were reduced at 400°C for 40 min, the charge transfer resistance of prepared samples was reduced from 43.67 to 19.35 Ω, and the pseudocapacitive contribution of TiNb2O7 was increased from 44% to 59%. In addition, the discharge capacities at 0.1 and 20 C of prepared batteries were increased by 10.84% and 105.85%, respectively. On the other hand, increasing the temperature in the reduction treatment caused the formation of Ti4+/Ti3+ and Nb5+/Nb4+ pairs and decreased the amounts of available redox couples, thereby deteriorating the electrochemical performance of prepared batteries. The results in the present study revealed that the discharge capacities and rate capability of TiNb2O7 powders were enhanced through a postreduction treatment. [ABSTRACT FROM AUTHOR]

Silicon, as the most promising advanced anode material for lithium‐ion batteries, faces challenges in large‐scale industrial production due to the significant volume expansion effect. In this investigation, Si/CNTs/C composite materials were effectively produced through high‐temperature carbonization utilizing asphalt, silicon, hexahydrate ferric chloride, and melamine as primary elements. The distinctive dual‐carbon framework of asphalt‐derived carbon and carbon nanotubes alleviates the volume expansion of silicon, thereby stabilizing the composite material's structure. Testing the electrochemical performance reveals that the Si/CNTs/C composite material exhibits a reversible specific capacity of 1187 mAh g−1 with a capacity retention rate of 92.6 % after 150 cycles at a current density of 0.2 A g−1. Even after 500 cycles at a current density of 1 A g−1, it sustains a specific capacity of 879.4 mAh g−1 with a capacity retention rate of 87.9 %, showcasing outstanding electrochemical performance. [ABSTRACT FROM AUTHOR]

The commercialization of high‐capacity silicon materials in lithium‐ion batteries is hindered by significant volume changes. Composite anodes made from silicon and graphite, which increase battery capacity and maintain electrode structural stability, are receiving considerable attention. However, the spatial configuration of the active particles in the electrode is few investigated due to the complexity of experiments at the microscopic scale. Herein, this work focuses on electrochemical, mass transport, and stress coupling mechanisms by considering different spatial configurations of silicon and graphite. In situ electrochemical and stress measurements are first conducted to demonstrate the impact of the active material arrangement. Then, a 2D electrochemical‐mechanical model is developed considering the heterogeneity of electrochemical processes at the particle‐electrolyte interface. The results show that placing silicon in the upper active layer significantly reduces the ion transport resistance, while the graphite layer near the current collector provides a good conductive network for electron transport in the silicon layer, enhancing the performance of the composite electrode structure. By combining electrochemical and mechanical field models with experimental verification, this study deepens the understanding of composite electrode structure design, offering practical guidance for optimizing the spatial configuration of electrode materials to significantly improve battery performance. [ABSTRACT FROM AUTHOR]

Molybdenum trioxide (MoO3) is a promising positive electrode material for aqueous aluminum‐ion batteries (AAIBs) due to its high theoretical capacity. However, MoO3 faces several challenges in an aqueous electrolyte, such as easy dissolution of reaction products, volume expansion, and low conductivity, which severely limit its application in aqueous batteries. In this work, we effectively increased the overall conductivity of the electrode by in situ growing MoO3 on the Mo2C MXene layer. MXene can effectively inhibit the dissolution and structural loss of MoO3 reaction products. Additionally, the coordination effect of Mo2C and MoO3 achieves a stable near‐surface reaction on the MXene laminates, resulting in the Mo2C/MoO3 composite exhibiting excellent aluminum storage properties (123.5 mAh/g after 200 cycles at 0.4 A/g). The energy storage mechanism of H+/Al3+ co‐insertion/extraction was elucidated through ex situ characterization, and the promotion effect of Mo2C on MoO3 reaction kinetics was verified by density functional theory (DFT) calculations. This work provides new insights into improving the stability of AAIBs cathodes and extends the application of Mo‐based MXene in aqueous batteries. [ABSTRACT FROM AUTHOR]

Aqueous zinc ion batteries (AZIBs) are considered one of the most prospective new‐generation electrochemical energy storage devices with the advantages of high specific capacity, good safety, and high economic efficiency. Nevertheless, the enduring problems of low Coulombic efficiency (CE) and inadequate cycling stability of zinc anodes, originating from dendrites, hydrogen precipitation and passivation, are closely tied to their thermodynamic instability in aqueous electrolytes, which significantly shortens the cycle life of the battery. Electrolyte additives can solve the above difficulties and are important for the advancement of affordable and reliable AZIBs. Organic electrolyte additives have attracted widespread attention due to their unique properties, however, there is a lack of systematic discussion on the performance and mechanism of action of organic electrolyte additives. In this review, a comprehensive overview of the application of organic electrolyte additives in AZIBs is presented. The role of organic electrolyte additives in stabilizing zinc anodes is described and evaluated. Finally, further potential directions and prospects for improving and directing organic electrolyte additives for AZIBs are presented. [ABSTRACT FROM AUTHOR]

Lithium‐ion batteries (LIBs) with ternary oxide cathode materials are the prevalent energy storage devices for electric vehicles, and the huge amounts of spent LIBs pose severe challenges in terms of environmental impact and resource management. Particularly, the proper handling of degraded cathode materials is of central importance for the sustainable and closed‐loop development of LIBs industry. In this context, direct regeneration of degraded ternary oxides toward reusable high‐performance cathode materials is environmentally and economically favorable in contrast to present metallurgical recycling methods. In this work, a simple and effective two‐step method is demonstrated to regenerate the degraded NCM 622 (LiNi0.6Co0.2Mn0.2O2) materials by elemental compensation and structural restoration. Moreover, a multi‐functional LTO (Li4Ti5O12) surface coating is simultaneously designed to guarantee rapid Li+ diffusion and stable surface of the regenerated product. Therefore, the regenerated LTO‐coated NCM materials show excellent electrochemical performance; specifically, the initial discharge capacity (183.0 mAh g−1 at 0.1 C), rate capability (90.0 mAh g−1 at 10 C), and cycling stability (79.3% capacity retention after 200 cycles) are even comparable with those of fresh materials. The as‐established upcycling strategy may shed light on the value‐added recycling of degraded cathode materials and thereby a virtuous cycle of LIBs. [ABSTRACT FROM AUTHOR]

Highlights Manganese oxides have emerged as promising electrode materials for supercapacitors. Despite extensive efforts to improve their conductivity and structural stability through various manganese oxide/conductor nanocomposites, achieving efficient and reliable energy storage electrode materials has remained challenging. In this study, we propose a meticulous “dual enhancement” strategy, where three‐dimensional (3D) nanostructured polyaniline/manganese oxide composites (PM) are synthesized via an in situ method and further integrated with graphene wrapping to form polyaniline/manganese oxide/graphene nanocomposites (PMG). Electrochemical characterization reveals that PMG exhibits a remarkable specific capacitance of up to 403 F g−1 (at 1 A g−1), with a favorable capacitance retention of 80.2% after 5000 cycles, along with a wide potential window. This enhancement is attributed to the synergistic effects of polyaniline, which provides a supportive framework and electron transport pathways, and graphene, which offers external protection and enhances conductivity pathways. Assembled symmetrical supercapacitors demonstrate outstanding energy density (32.7–23.3 Wh kg−1) and power density (720–4500 W kg−1) at a high operating voltage of 1.8 V, surpassing the performance of many reported high‐performance supercapacitors. This study provides valuable insights for advancing manganese oxide electrode materials and is expected to catalyze their widespread adoption in energy storage applications. “Dual enhancement” is implemented by PANI supporting and rGO wrapping. The conductivity and structural stability of composite electrode is greatly enhanced. Improved capacitance (403 F g−1, 1 A g−1) and cycling stability (80.2%) is achieved. The symmetrical supercapacitor has high voltage and energy density (32.7 Wh kg−1). [ABSTRACT FROM AUTHOR]

This study presents a novel approach to the development of high-performance supercapacitors through 3D printing technology. We synthesized a composite material consisting of silver-doped reduced graphene oxide (rGO) and dodecylbenzenesulfonic acid (DBSA)-doped polyaniline (PANI), which was further blended with polylactic acid (PLA) for additive manufacturing. The composite was extruded into filaments and printed into circular disc electrodes using fused deposition modeling (FDM). These electrodes were assembled into symmetric supercapacitor devices with a solid-state electrolyte. Electrochemical characterization, including cyclic voltammetry (CV) and galvanostatic charge–discharge (GCD) tests, demonstrated considerable mass-specific capacitance values of 136.2 F/g and 133 F/g at 20 mV/s and 1 A/g, respectively. The devices showed excellent stability, retaining 91% of their initial capacitance after 5000 cycles. The incorporation of silver nanoparticles enhanced the conductivity of rGO, while PANI-DBSA improved electrochemical stability and performance. This study highlights the potential of combining advanced materials with 3D printing to optimize energy storage devices, offering a significant advancement over traditional manufacturing methods. [ABSTRACT FROM AUTHOR]

This work vividly demonstrates the rational design of VSe 2-x O x -SS cathode as an effective strategy to achieve fast and highly aqueous zinc ion storage. [Display omitted] • A simple and fast surface oxygen implantation strategy was designed to adjust the electronic structure of VSe 2 and form a surface protective film. • The VSe 2-x O x -SS-30 electrode showed higher specific capacity, better rate performance and more satisfactory cycling stability. • The zinc (de)intercalation and transformation reactions mechanism was revealed by some ex-situ/in-situ techniques. Interfacial chemical modification is an effective strategy to adjust the strong Coulombic ion-lattice interactions with high valence cations experienced by electrode materials, facilitating the reaction kinetic. In this paper, a simple and fast surface oxygen implantation strategy was designed to adjust the electronic structure of stainless steel (SS) supported vanadium diselenide (VSe 2) nanosheets and form a surface protective film, which effectively accelerates the reaction kinetics of Zn2+ and extends the cycle life of the battery. It is demonstrated that the conductivity, pseudocapacitance and specific capacity can be tuned by selectively introducing oxygen species to the surface, which provides an important reference for the design of electrodes with controlled surface chemistry. Density functional theory (DFT) calculations also confirm that the electronic structure can be adjusted by surface oxygen injection strategy, which not only improves the conductivity, but also adjusts the adsorption energy, thus providing favorable conditions for zinc ion storage. Benefiting from the selenium vacancies and pores generated by the removal of part of selenium, and the oxide film formed on the surfaces, the VSe 2-x O x -SS-30 electrode showed higher specific capacity (188.4 mAh/g at 0.5 A g−1 after 50 cycles), better rate performance (107.1 mAh/g at 4 A g−1) and more satisfactory cycling stability (83.1 mAh/g at 5 A g−1 after 1800 cycles) than VSe 2 -SS electrode. Importantly, the flexible quasi-solid-state VSe 2-x O x -SS-30//Zn battery also exhibits high specific capacity and excellent environmental adaptability. Furthermore, the zinc (de)intercalation and transformation reactions mechanism was revealed by some ex-situ/in-situ techniques. [ABSTRACT FROM AUTHOR]

Layered double hydroxides (LDHs) represent a category of two-dimensional layered intercalation materials, showing significant potential as electrode materials for the production of high-energy-density supercapacitors due to their tunable composition, ease of synthetic modification, and low cost. Here, we constructed alkali-etched NiAl LDH-OH nanosheets/Ag nanoparticles (NPs) composite material (Ag@NiAl LDH-OH) for high-performance supercapacitors through a simple solvent-thermal reaction. The alkali treatment is employed to selectively etch some Al3+ ions, generating cation vacancies as active sites for energy storage. Additionally, under the simultaneous influence of strong alkalis and vacancies, the interlayer spacing of LDHs expands, aiding in the promotion of interlayer ion mobility. Meanwhile, the decoration of silver nanoparticles ensures excellent electron conductivity in the NiAl-LDH-OH nanosheets, thereby facilitating improved utilization of the active substance and achieving outstanding rate performance. The Ag@NiAl LDH-OH electrode, when prepared, demonstrates a significant increase in specific capacitance, reaching 1790 F g−1 at a current density of 1 A g−1. This represents approximately 7 times the specific capacitance of the pristine NiAl LDH electrode, with a capacity retention of 79 % even under a high current density of 20 A g−1. Moreover, the assembled asymmetric supercapacitor (ASC) attains a maximum energy density of 138.25 Wh kg−1 at a power density of 700 W kg−1, maintaining 81 % of its initial specific capacitance after 20000 cycles. This research introduces novel pathways for advancing high-energy-density SCs. [ABSTRACT FROM AUTHOR]

Silicon (Si) anode is of considerable interest in Li‐ion batteries due to its high theoretical capacity (4200 mAh g−1), abundant reserves in the earth, and environmentally friendly nature. Although Si anode has significant advantages, the electrode is prone to cracks due to large volume changes in its structure during discharge cycles in Li‐ion batteries. Rapid capacity degradation occurs as a result of deterioration of the structural integrity of the electrode. Although binders are known to contribute to improving the electrochemical performance of anode materials, polyvinylidene fluoride (PVdF) used in commercial Li‐ion batteries cannot maintain the mechanical stability of the Si anode during cycles due to weak Van der Waals interactions, which also dissolves in the flammable, explosive and volatile solvent N‐Methyl‐2‐pyrrolidone (NMP). In this study, low cost, sustainable and environmentally green psyllium gum (PG) was extracted from psyllium husk and tested for the first time as a water‐soluble binder for Si anode. According to galvanostatic charge/discharge tests, the Si‐PG anode exhibits a capacity of 1415 mAh g−1 after 100 cycles at a voltage range of 0.01–1.5 V and current density of C/2, which is almost 3 times higher than the Si‐PVdF anode (494 mAh g−1). [ABSTRACT FROM AUTHOR]

Microtubular (MT) geometry of solid oxide cells have a number of distinctive properties, such as high volumetric power density, thermocycling stability and fast start-up capability. In this study, we evaluate the performance of the MT cell with LNO-SDC as air electrode under both fuel cell and electrolysis cell mode operation. While working in the fuel cell mode, the maximum power densities of MT cell reached 533, 740 and 792 mW cm−2 at 750, 800 and 850 °C, respectively. Moreover, the MT cell exhibit excellent long-term stability with no critical performance degradation operating at 750 °C. In the electrolysis mode, current density at 800 °C reached value of 780 mA cm−2 under applied voltage of 1.3 V with fuel gas containing 30 % H 2 O. The results on CO 2 electrolysis indicate remarkable efficiency of studied MT cell with current density of 854 mA cm−2 at an applied voltage of 1.5 V. • Microtubular solid oxide cells with LNO-SDC air electrode were fabricated. • Maximum power density reached 792 mW cm−2 in H 2 (3% H 2 O). • Under steam electrolysis condition, current density of 780 mA cm−2 was obtained at 1.3 V with 30 % H 2 O in fuel gas at 800 °C. • MT cell demonstrated great performance under CO 2 electrolysis condition. • Long-term stability is investigated. [ABSTRACT FROM AUTHOR]

Large volume changes and low electronic conductivity limit the advancement of mixed metal vanadate oxides as anode materials in lithium-ion batteries. Herein, ultrafine Co3V2O8 nanoparticles with a diameter of 7–9 nm are embedded in situ within the walls of hollow carbon combination spheres (HCCSs) through spray drying and calcination process. Each unit sphere of HCCS has an internal cavity of 170 nm and a wall thickness of 12 nm. When tested in lithium-ion half-cells, Co3V2O8/HCCS sustains a high reversible capacity of 1043 mAh g–1 at 0.2 A g–1 after 120 cycles, 832 mAh g–1 at 0.5 A g–1 after 580 cycles, and 759 mAh g–1 at 1.0 A g–1 after 800 cycles. Kinetics investigation uncovers a noticeable pseudocapacitive effect. Li+ diffusion coefficient ranges from 1.12 × 10–12 to 6.62 × 10–14 cm2 s–1. Electrochemical impedance spectroscopy revealed low Ohmic resistance and charge transfer resistance, confirming efficient Li+ diffusion. The full cell also exhibits excellent cycling performance and rate capability. The exceptional electrochemical performance is associated with the unique hollow carbon combination sphere and the embedded structure of ultrafine Co3V2O8 nanoparticles. The former improves the structural strength, facilitates ion transport and electronic conduction, and prevents Co3V2O8 detachment from the composite. The latter further suppresses the volume variation of Co3V2O8 and enhances its electrochemical activity. [ABSTRACT FROM AUTHOR]

Silicon oxides (SiOx) have received extensive attention as a promising anode candidate for next‐generation lithium‐ion batteries (LIBs). However, their commercial applications have been seriously hindered by low conductivity, large volume expansion, and unstable solid‐electrolyte interface (SEI) layer, which result in low initial coulombic efficiency, poor rate performance, and short cycling lifespan. In this work, we demonstrated a simple way to prepare a series of SiOx materials with lithium fluoride (LiF) modified. When the mass ratio of SiOx and LiF equaled 1 : 0.15, the long‐term cycling capacity retention could be greatly improved from 30.1 % to 76.5 % after 300 cycles. The result was primarily because of the enhancement of electrons and Li+‐ions transport and the stability of the SEI layer due to LiF addition. However, excess LiF addition could hinder the diffusion of Li+‐ions. This study presented the great potential of LiF modified on SiOx anode materials for LIBs. [ABSTRACT FROM AUTHOR]

The photo‐assisted strategy is regarded as a crucial approach to enhance the conversion kinetics of polysulfides in lithium–sulfur (Li–S) batteries. However, the development of photo‐assisted Li–S batteries still faces important challenges, such as the rapid recombination of photogenerated electron−holes on cathode and more severe shuttle effect. Herein, a breakthrough in overcoming the challenges has been made by constructing a promising photo‐assisted Li−S battery based on semiconducted metal−organic frameworks. During the discharging progress, the photoexcited electrons generated by H2BPDC ligand based on ligand‐to‐metal charge transfer (LMCT) effect, are injected into the Ti‐oxo clusters in Ti‐MOF, thereby facilitating the sulfur reduction to Li2S. And photoexcited holes are capable of promoting the decomposition kinetics of Li2S during charging. More importantly, the stronger chemical interaction between Ti‐BPDC‐d and polysulfides under light inhibits the polysulfides dissolution and shuttling, which fundamentally addresses the issue of light‐accelerated shuttling. As a result, the photo‐assisted Li–S batteries deliver a reversible capability of 1090.21 mAh g−1 at 0.2 C with a capacity retention of 82.91% over 150 cycles, and a superior rate capability of 673.58 mAh g−1 at 5 C. The findings are promising in advancing the design principles for photo‐rechargeable Li−S batteries. [ABSTRACT FROM AUTHOR]

Highlights: Optimization strategies for high-performance Na3V2(PO4)3 (NVP) cathode material are well summarized and discussed, including carbon coating or modification, foreign-ion doping or substitution and nanostructure and morphology design. The foreign-ion doping or substitution is highlighted, involving the Na, V, and PO43− sites, which include single-site doping, multiple-site doping, single-ion doping and multiple-ion doping. Challenges and future perspectives for high-performance NVP cathode material are presented. Na3V2(PO4)3 (NVP) has garnered great attentions as a prospective cathode material for sodium-ion batteries (SIBs) by virtue of its decent theoretical capacity, superior ion conductivity and high structural stability. However, the inherently poor electronic conductivity and sluggish sodium-ion diffusion kinetics of NVP material give rise to inferior rate performance and unsatisfactory energy density, which strictly confine its further application in SIBs. Thus, it is of significance to boost the sodium storage performance of NVP cathode material. Up to now, many methods have been developed to optimize the electrochemical performance of NVP cathode material. In this review, the latest advances in optimization strategies for improving the electrochemical performance of NVP cathode material are well summarized and discussed, including carbon coating or modification, foreign-ion doping or substitution and nanostructure and morphology design. The foreign-ion doping or substitution is highlighted, involving Na, V, and PO43− sites, which include single-site doping, multiple-site doping, single-ion doping, multiple-ion doping and so on. Furthermore, the challenges and prospects of high-performance NVP cathode material are also put forward. It is believed that this review can provide a useful reference for designing and developing high-performance NVP cathode material toward the large-scale application in SIBs. [ABSTRACT FROM AUTHOR]

In this research, two electrocatalysts (Ni–Co–Cu/NG-1 and Ni–Co–Cu/NG-2) were synthesized by combined use of nitrogen-doped graphene (NG) and cobalt, copper and nickel with different metallic content. The synthesis procedure was optimized such that nickel and cobalt are composed in hydroxide form and the copper is formed as copper oxide. The electrocatalytic performance of the electrocatalysts studied by cyclic voltammetry for glucose oxidation and the eletrocatalyst with higher metal content displayed a larger current density (30.22 mA/cm2) in comparison to the other electrocatalyst (22.72 mA/cm2). This enhancement stems from the synergistic effects of the composite materials in the electrocatalysts. Moreover, graphene oxide plays a key role in improving the movement of electrons on the electrocatalysts surface, which leads to improving the catalytic performance of the catalyst. The durability of the catalysts was evaluated and the results showed that the current decline of the Ni–Co–Cu/NG-1 catalyst was larger than the Ni–Co–Cu/NG-2 electrocatalyst. [Display omitted] • Preparation electrocatalysts by use of N-doped graphene oxide and Ni, Co and Cu. • The electrocatalyst with higher metal content displays superior catalytic activity. • The synergistic effect of Co, Cu, and Ni improved electrochemical performance. [ABSTRACT FROM AUTHOR]

This review comprehensively introduces and summarizes the roles of various pore structures and the research progress on different hierarchical porous carbon (HPC) materials used as capacitive deionization (CDI) electrodes・ The study also highlights the challenges faced by HPC as a CDI electrode material in practical applications, such as the limited development and utilization of environmentally friendly activators, the necessity for a deeper understanding of the structure-performance relationship between HPC and pseudocapacitive materials, and the lack of research on system design. Furthermore, it outlines the future development directions in the capacitive deionization field, offering valuable insights for researchers aiming to create environmentally friendly, low・carbon, and high-performance CDI electrode materials. [ABSTRACT FROM AUTHOR]

Cobalt-vanadium layered bimetallic hydroxide (CoV-LDH) is rich in electrochemically active sites, but still suffers from the problems of expensive low-priced vanadium sources, difficult preparation, and vanadium dissolution. In this study, three-dimensional porous CoV-LDH electrode materials were prepared by electrochemical cathodic reduction, and in order to improve the stability of CoV-LDH in alkaline electrolyte, the core-shell structure CoV-LDH@NiCo-LDH composites were constructed by secondary electrodeposition, which have the microscopic morphology of nanosphere-coated nanosheets and the uniform distribution of the three elements of Ni, Co, and V. This increased the contact area of the material's active sites and the electrolyte, and reduced the contact area of vanadium. With the uniform distribution of Ni, Co and V elements, the contact area between the active sites and the electrolyte is increased, the interfacial impedance of the material is reduced, and the pseudocapacitive energy storage performance is greatly improved. Under the current density of 1 A/g, the specific capacitance of CoV-LDH@NiCo-LDH reaches 995.8 F/g, which is much better than that of CoV-LDH (575.2 F/g), with a significant increase of 73.1% in the specific capacitance, and it has excellent multiplicative performance, and the pseudocapacitance accounts for 85% of the total capacitance under the sweeping speed of 50 mV/s. The cycling stability reaches 85% after 2 000 cycles. Analyzing the reaction kinetics and energy storage mechanism of the NiCo-LDH@CoV-LDH electrode material, it exhibits not only the battery-type Faraday behavior but also the capacitive properties. The anode material was assembled with an activated carbon (AC) negative electrode to form a CoV-LDH@NiCo-LDH:||AC asymmetric supercapacitor, with a specific capacitance of up to 222.2 F/g at a current density of 1 A/g, and an energy density of 30.86 Wh/kg at a power density of 222.2 W/kg. This work lays the foundation for the vanadium-based bimetallic hydroxide material, preparation of vanadium-based bimetallic hydroxide materials and energy storage applications. [ABSTRACT FROM AUTHOR]

As the negative electrode material of lithium-ion battery, silicon will produce huge volume expansion when it is removed/embedded in lithium, so that it will pulverize itself, resulting in rapid capacity decay. Existing studies have shown that Si nanocrystallization and alloying can alleviate the crushing effect caused by volume deformation. In order to efficiently prepare nano-sized Si-Sn powder materials, plasma arc was used as a heat source to nano-size Si, and then nano-alloying of Si-Sn powder materials was realized by plasma arc. The effects of plasma current on the preparation characteristics of Si and Si-Sn nano-powder materials were studied. The prepared phase was detected by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The electrochemical properties of silicon nanowires as anode materials were detected by battery test system and electrochemical workstation. The results show that the use of plasma arc can achieve efficient preparation of silicon nanowires, and the addition of low melting point Sn is beneficial to the homogenization of the diameter scale of silicon nanowires. The efficiency of the two groups of silicon nanowires can be maintained at about 90% after the third charge-discharge cycle. The addition of Sn can further improve the conductivity and stability of the silicon anode. After 60 cycles, the specific capacity of the battery is 117.5 mAh/g. [ABSTRACT FROM AUTHOR]

Aluminum‐ion batteries (AIBs) are promising electrochemical energy storage sources because of their high theoretical specific capacity, light weight, zero pollution, safety, inexpensiveness, and abundant resources. These theoretical advantages have recently made AIBs a research hotspot. However, electrolyte‐related issues significantly limit their commercialization. The electrolyte choices for AIBs are significantly limited, and most of the available options do not facilitate the Al3+/Al three‐electron transfer reaction. Thus, this review presents an overview of recent advances in electrolytes and modification strategies for AIBs to clarify the limitations of existing AIB electrolytes and offer guidance for improving their performance. Furthermore, herein, the advantages, limitations and possible solutions for each electrolyte are discussed, after which the future of AIB electrolytes is envisioned. [ABSTRACT FROM AUTHOR]

A series of Ni3S2 electrocatalysts were successfully prepared using nickel foam precursor as substrate and thiourea, sodium thiosulfate pentahydrate, sodium sulfide nonahydrate and sodium diethyldithiocarbamate as sulfur sources, and their performances in electrocatalytic hydrogen evolution (HER) were further compared. The results exhibited that the Ni3S2 catalyst prepared with sodium thiosulfate pentahydrate as the sulfur source showed the best performance in HER. At a current density of 10 mA cm−2, the overpotential was only 178 mV, and the Tafel slope was 70.4 mV dec−1. In addition, through the double-layer capacitance test, it was found that the catalyst had the highest electrochemical active area, and the capacitance reached 41.33 mF cm−2, which was consistent with its excellent HER performance. In this work, the influence mechanism of different sulfur sources on the sulfurization process of Ni3S2 catalyst and the further impact of these effects on the performance of HER were also discussed in detail. These results provide a solid theoretical and experimental basis for optimizing the application of Ni3S2 catalyst in the field of electrocatalytic hydrogen production. [ABSTRACT FROM AUTHOR]

Large-scale application of MFCs is limited by the high cost of electrode and low power density. In this study, the electrochemical structure and power output performance of three novel straw-derived biochar are discussed and characterized by scanning electron microscope, specific surface area, cyclic voltammetry, Raman spectrum, electrochemical impedance spectroscopy etc. Compared with the common carbon felt electrode, the optimal electricity generation ability and electrochemical affinity are obtained in corn straw biochar electrode: the rough surface with macroporous structure and high degree of graphitization facilitates the attachment of electroactive bacteria; the maximum output voltage, open circuit voltage, power density and coulombic efficiency reach 662.64±4.03 mV, 798.24±3.65 mV, 1.54±0.18 W m−2 and 50.39±1.68 %, respectively; the maximum COD removal efficiency of 77.45±1.69 % is achieved; exchange current density (4.6142×10−4 A cm−2) in corn straw electrode presents the better electrochemical activity than that of carbon felt electrode. These implies that corn straw-derived biochar is a competitive raw material for MFC anode. [Display omitted] • Biochar is equipped with natural macroporous structure and excellent conductivity. • Straw biochar electrode is economical and environmentally friendly. • Corn straw biochar electrode is superior in electrochemical performance and pollutant removal effect. [ABSTRACT FROM AUTHOR]

One-dimensional copper sulfide (CuS) wires were realized by the acrylamide-assisted hydrothermal process using Cu(NO3)2 and thiourea (NH2CSNH2) as reactants at 100 °C. A copper sulfide/carbon nanotube (CNTs) composite was fabricated as a similar method with the addition of CNTs. The samples are characterized by XRD, SEM, TEM, and Raman scattering spectra, respectively. The influence of reaction temperature and amine on the morphologies of CuS nanocrystals was investigated. As anode materials for sodium-ion batteries, the electrochemical studies show that the CuS/CNT composite electrode delivers a higher reversible capacity of 428.1 mA h g−1 at 0.1 A g−1 for the 100th cycle, because CNTs can be a conductive agent to provide a fast path for electron transportation, compared with the bare CuS wires (280 mAh·g−1 after 100 cycles). The synthesis results indicate that the amine-directed synthesis strategy of copper sulfide could be extended for the preparation of other metal sulfide nanostructures. Further, the incorporation of the CNT matrix into the copper sulfide is an effective approach to enhance the electrochemical performance of CuS. [ABSTRACT FROM AUTHOR]

Polythiophene (PTh) was modified with tin oxide (SnO2) and tin sulphide (SnS2) nanoparticles to enhance its electrochemical performance. The resulting PTh/SnO2/SnS2 material was characterized to understand its surface influence, crystalline structure, and electrochemical behavior, and the results were compared with those of pristine PTh. The study revealed that surface modification improved the structural stability of PTh while maintaining its specific capacitance. Electrochemical properties were assessed using cyclic voltammetry (CV) and AC impedance techniques in a 3 M KOH electrolyte, yielding specific capacitances of 226 F g− 1 for PTh, 571 F g− 1 for PTh/SnO2, 625 F g− 1 for PTh/SnS2, and 946 F g− 1 for PTh/SnO2/SnS2 at 5 A g− 1. This enhancement was attributed to the synergistic effect of the Sn4+ ions in the PTh/SnO2/SnS2 electrode material. In the KOH electrolyte, the PTh/SnO2/SnS2 electrode demonstrated an average specific energy and specific power density of 681 Wh kg− 1 and 5273 W kg− 1, respectively. Remarkably, only 7% of the initial capacitance was lost after 10,000 cycles. The resulting PTh/SnO2/SnS2 nanocomposite exhibited stable and porous layered structures, indicating its potential for supercapacitor applications. The integration of SnO2 and SnS2 nanoparticles enhances the structural stability of polythiophene films. This improved stability ensures that the films can maintain their integrity and functionality over multiple charge-discharge cycles, leading to a longer lifespan in supercapacitor devices. This study demonstrated that PTh/SnO2/SnS2 nanomaterials offer good structural stability and electrochemical performance, making them promising materials for supercapacitors. [ABSTRACT FROM AUTHOR]

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Graphene-based aerogels have garnered significant attention due to their combined advantages derived from both graphene and aerogels. Nevertheless, a key limitation in their practical applications arises from their relatively modest specific surface area and pore volume. In this study, porous graphene materials with high porosity are synthesized through the physical and chemical activation of nitrogen-doped graphene aerogel (NGA) using carbon dioxide and KOH as activating agents. The carbon dioxide-activated NGA (CNGA) maintains the spongy aerogel structure and exhibits a hierarchical porous structure encompassing micropores, mesopores, and macropores. Notably, CNGA exhibits a high specific surface area (2030 m2 g–1) and pore volume (5.4 cm3 g–1). Given its intriguing properties, the CNGA porous material shows exceptional adsorption capabilities for toluene (2625 mg g–1) and methanol (2091 mg g–1) under saturated vapor pressure conditions, making it possible to serve as an efficient gas adsorbent. Furthermore, the CNGA as a sulfur host for lithium–sulfur battery demonstrates good cycling performance, retaining a discharge specific capacity of 719.6 mA h g–1 even after 200 cycles at a rate of 0.5 C. [ABSTRACT FROM AUTHOR]

The poor structural stability and cyclability restrict the wide application of natural graphite (NG) in Li-ion batteries (LIBs). Herein, NG was hydrothermally modified with KCl at 200 °C for 12 h. The NG modified with 1.0 wt% KCl exhibits excellent rate performance (revealing average lithiation capacities of 407.7 mAh g−1 at 0.1 C and 341.2 mAh g−1 at 0.5 C) and cyclability. The roles of K+ and Cl− in promoting the electrochemical performance of NG was revealed via systematic characterizations. In the hydrothermal process, K+ entered into graphene interlayers to enhance electronic conductivity and introduce lattice distortion in NG to facilitate Li-ion transport during lithiation and delithiation, while Cl− interacted with the NG surface to create C‒Cl bonds which are partially converted into Li-conductive LiCl during lithiation to function as the component of solid electrolyte interphase. Both the residual C‒Cl bonds and in situ formed LiCl with high stability could stabilize the structure and performance of the NG anode. This simple hydrothermal modification with KCl might promote the wide utilization of the NG anode in LIBs. [ABSTRACT FROM AUTHOR]

With the continuous development of new energy application technology, there is an increasingly urgent need for the safety and affordability of new energy storage products. In recent years, aqueous zinc-ion batteries based on mild aqueous electrolytes have garnered widespread attention as a potential replacement for traditional lithium-ion batteries. However, the limited capacity and low operating voltage of aqueous zinc-ion batteries restrict their widespread application. For this reason, sulfuric acid was added to the electrolyte, which effectively promotes the two-electron conversion of MnO2/Mn2+ during the discharge process. This enhancement results in the high voltage segment of the batteries' discharge phase offering a higher reversible specific capacity. The results showed that the batteries with 0.1 M H2SO4 added to the electrolyte had a reversible discharge-specific capacity of up to 536.07 mAh·g−1 at a current density of 100 mA·g−1. The activated batteries exhibited a reversible specific capacity of 85.11 mAh·g−1 even at a high current density of 1 A·g−1. Furthermore, the capacity retention rate after 1000 cycles was 88.3%. Moreover, the activation rate of the batteries was faster with the addition of H2SO4, and the average operating potential increased compared to the batteries without H2SO4 in the electrolyte. This provides an effective solution for the practical application of aqueous zinc-ion batteries in power grids. [ABSTRACT FROM AUTHOR]

Solid-state lithium batteries (SSBs) have attracted attention as the next-generation high-safety lithium batteries due to their high energy density, excellent security, and electrochemical stability. Currently, polyvinylidene fluoride (PVDF) is considered one of the most crucial materials in solid polymer electrolytes because of its flexibility and workability. However, PVDF-based solid electrolytes encounter challenges such as low electrical conductivity and high internal resistance. The electrochemical properties of these solid electrolytes can be effectively enhanced through composite design and molecular structure modification. This review specifically focuses on the impact of nano-fillers with different structures (zero-dimensional nanoparticles, one-dimensional nanofibers, two-dimensional nanosheets, and three-dimensional nanoskeleton structures) on the key properties of PVDF-based solid electrolytes. The specific focus is on optimizing ion conductivity, improving lithium-ion migration efficiency, expanding the electrochemical stability window, extending battery life, enhancing electrical performance stability, and increasing battery capacity. The goal is to explore innovative filler design and modification technology application strategies in order to effectively enhance the performance of PVDF-based solid electrolytes in the field of solid lithium-ion batteries. [ABSTRACT FROM AUTHOR]

Three different ionic surfactants (CTAB, SDS, and PEG) were capped synthesized ZnO-NiO nanocomposites via co-precipitation method. The primary goal of the present work is tuning the crystallite size, morphology, particle size, energy gap, and luminescence of ZnO-NiO nanocomposites under the influence of surfactant agents through powder XRD, SEM, UV–visible, and fluorescence measurements. The bi-phase crystalline structure has been identified in synthesized ZnO-NiO samples with the assistance of powder XRD analysis. The TEM image of the CTAB-capped ZnO-NiO composite revealed a uniformly dispersed spherical-like structure of the particles. Further, formations of zinc oxide–nickel oxide have also been supported by the EDX study. The optical band gap values are relatively higher (3.17 eV) in CTAB-capped ZnO-NiO composites than SDS-capped (3.12 eV), and PEG-capped (3.10 eV) through identified as UV–visible spectra. From the fluorescence spectra, strong visible emission peaks were detected at 632 nm in all synthesized ZnO-NiO nanocomposites. The second aim of the present work, in terms of the better size and optical properties of CTAB-capped ZnO-NiO composites, has been taken to further investigate photocatalytic and electrochemical properties through photocatalytic experiments and cyclic voltammetry measurements. Orange Gelb (OG), Amidoblack 10B (AB10B), and Direct Blue 71 (DB71) dyes, along with CTAB-capped ZnO-NiO nanocomposites, were employed as photocatalyst in a photocatalytic experiment under visible light illumination to test the photodegradation efficiency. Photodegradation efficiency of AB10B to be 99.145% is relatively higher than 95.92% (OG) and 94.88% (DB71) which is due to the photo absorption wavelengths of the chromophore and aromatic part of the dyes. In addition, the electrochemical oxidation peaks, current response, and corresponding potential of CTAB-capped ZnO-NiO were shifted under the influence of various scan rates using cyclic voltammetry (CV) analysis, which exhibits pseudocapacitance behavior. This work will pave the way for the synthesized sample's use in waste-water treatment and supercapacitor applications. [ABSTRACT FROM AUTHOR]

Double-perovskite oxide PrBaFe2O5+δ (PBF) is considered as a potential electrode material because of its superior oxygen reduction reaction (ORR) activity in air and excellent stability in wet hydrogen atmospheres. However, the electrochemical activities of Fe-based electrode materials are constrained by the oxygen vacancy concentration and oxy-ion transport properties. Herein, PrBaFe2-xNbxO5+δ (PBFNx, x = 0, 0.05, 0.1, 0.15) oxides are synthesized and evaluated as electrodes for symmetrical solid oxide fuel cell (SSOFC). X-ray diffraction (XRD) indicates that PBFNx samples have an orthorhombic structure and good chemical compatibility with electrolyte. Among all the samples, the PBFN0.1 symmetrical half-cell shows the lowest polarization resistance at 800 °C, which decreases by 29.2% compared with that of PBF in air and decreases by 59.9% compared with that of PBF in wet hydrogen atmospheres. The output performance of the single cell with PBFN0.1 as symmetrical electrodes achieves 197.10 mW cm−2 in wet hydrogen atmospheres at 800 °C, which is an improvement of 31.97% compared with that of PBF. The enhanced electrochemical performance can be attributed to an increase in oxygen vacancy concentrations. The results suggest that the PBFN0.1 material is a potential candidate for SSOFC. [ABSTRACT FROM AUTHOR]

In this work, rutile-phase Ti0.95Nb0.95O4/C (TNO/C) composites with different carbon contents were obtained through solvothermal method and subsequent calcination. The effect of carbon component on the microstructure and electrochemical performances of TNO/C composites were investigated. The results indicate more oxygen vacancies, and higher contents of Nb4+ and Ti3+ can be obtained under higher carbon content, leading to enhanced conductivity. Besides serving as conductive agent, carbon component in TNO/C composites also acts as an active component for Li+ storage, and pseudocapacitance provided by carbon component increases with the increasing of its relative content. Therefore, TNO/C-27.0 composites with the highest carbon content in the as-prepared composites deliver the highest reversible capacities at different current densities and excellent cycling capability of 488 mAh·g−1 at 0.3 A·g−1 after 300 cycles and 331 mAh·g−1 at 1.0 A·g−1 after 500 cycles. [ABSTRACT FROM AUTHOR]

MXenes are a kind of novel and interesting new materials, and carbon dots (CDs) are also concerned because of their processability, versatility, environmental protection, and low cost. Both MXenes and CDs are chemically stable and have a large surface area and high electrical conductivity, which are promising alternative electrode materials for supercapacitors. Moreover, MnO2 can also improve the energy density of the electrode materials. In this paper, Ti3C2Tx/CDs and Ti3C2Tx/CDs@MnO2 were prepared by a hydrothermal method and their supercapacitor performance were also investigated by a series of electrochemical methods. From the CV profile in a three-electrode system, Ti3C2Tx/CDs@MnO2 electrode exhibited a high specific capacitance of 281.3 F g−1 at a scan rate of 5 mV s−1, which was higher than that of Ti3C2Tx/CDs (160.3 F g−1). Ti3C2Tx/CDs showed a good cycling stability with a capacitance retention of 82.38% after 10,000 cycles. Meanwhile, a symmetric supercapacitor was successfully assembled using Ti3C2Tx/CDs@MnO2 as electrodes, with an energy density of 5.77 Wh kg−1 at a corresponding power density of 120 W kg−1. This work offers a theoretical foundation and a technological path for synthesizing highly effective ternary composite of MXene-based as energy storage materials. [ABSTRACT FROM AUTHOR]

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Series of PO43−/Fe3+ co-doped samples of LiNi0.5Mn1.5-5/3xFexP2/3xO4 (x = 0.01, 0.02, 0.03, 0.04, 0.05) have been synthesized by the coprecipitation–hydrothermal method, along with high-temperature calcination using FeSO4 and NaH2PO4 as Fe3+ and PO43− sources, respectively. The effects of the PO43−/Fe3+ co-doping amount on the crystal structure, particle morphology and electrochemical performance of LiNi0.5Mn1.5O4 are intensively studied. The results show that the PO43−/Fe3+ co-doping amount exerts a significant influence on the crystal structure and particle morphology, including increased crystallinity, lowered Mn3+ content, smaller primary particle size with decreased agglomeration and the exposure of high-energy (110) and (311) crystal surfaces in primary particles. The synergy of the above factors contributes to the obviously ameliorated electrochemical performance of the co-doped samples. The LiNi0.5Mn1.45Fe0.03P0.02O4 sample exhibits the best cycling stability, and the LiNi0.5Mn1.4333Fe0.04P0.0267O4 sample displays the best rate performance. The electrochemical properties of LiNi0.5Mn1.5-5/3xFexP2/3xO4 can be regulated by adjusting the PO43−/Fe3+ co-doping amount. [ABSTRACT FROM AUTHOR]