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High surface area alumina-supported cobalt oxides and carbides were synthesized using a one-pot reverse microemulsion method (followed by carburization for carbides). Two reverse microemulsion synthesis variations gave fine powders having specific surface areas ranging from 178−272 m2/g, consisting of cobalt oxide or cobalt carbide nanoparticles (5−10 nm) dispersed on γ-alumina (10−13 wt% cobalt loadings). The resulted materials were tested for CO2 hydrogenation. Although all materials (two oxides and two carbides) were catalytically active, only cobalt carbides showed high selectivity to CH4 formation (up to 99 %), while also being significantly more active and stable than corresponding cobalt oxides (up to 89 % CO2 conversion for carbides). Investigation by in situ FTIR has shown significant differences in the reaction intermediates indicating different reaction mechanisms of CO2 hydrogenation on cobalt oxide and cobalt carbide surfaces.

Lithium-sulfur (Li-S) batteries are regarded as a promising next-generation system for advanced energy storage owing to a high theoretical energy density of 2600 Wh kg-1 . However, the practical implementation of Li-S batteries has been thwarted by the detrimental shuttling behavior of polysulfides, and the sluggish kinetics in electrochemical processes. Herein, a novel single atom (SA) catalyst with oversaturated Fe-N5 coordination structure (Fe-N5 -C) is precisely synthesized by an absorption-pyrolysis strategy and introduced as an effective sulfur host material. The experimental characterizations and theoretical calculations reveal synergism between atomically dispersed Fe-N5 active sites and the unique carbon support. The results exhibit that the sulfur composite cathode built on the Fe-N5 -C can not only adsorb polysulfides via chemical interaction, but also boost the redox reaction kinetics, thus mitigating the shuttle effect. Meanwhile, the robust three-dimensional nitrogen doped carbon nanofiber with large surface area, and high porosity enables strong physical confinement and fast electron/ion transfer process. Attributed to such unique features, Li-S batteries with S/Fe-N5 -C composite cathode realize outstanding cyclability and rate capability, as well as high areal capacities under raised sulfur loading, which demonstrates great potential in developing advanced Li-S batteries.

Electromagnetic pollution has become a serious issue with the ever-increasing development of portable technologies and commercialization of 5th generation wireless systems. Polymer composites of emerging nanomaterials such as 2D MXene Ti3C2Tx are promising candidates for manufacturing high-performance electromagnetic wave absorption materials. In this work, heterogeneous nanostructures of SiC-nanowire (SiCnw)/MXene were developed in a poly(vinylidene fluoride) (PVDF) matrix through electrostatic self-assembly, followed by solution casting and hot pressing. The synergism of the 2D MXene nanosheets and 1D SiCnw with numerous stacking faults in the structure created many heterogeneous interfaces in the polymer matrix. The unique nanostructures within the polymer matrix efficiently led to superior electromagnetic wave absorption properties. The SiCnws:MXene ratio and the SiCnw/MXene concentration were optimized to be SiCnw:MXene = 7:1 and 20 wt%, respectively, to achieve an effective bandwidth of 5.0 GHz over the Ku-band. A minimum reflection loss of −75.8 dB was found at the matching thickness from 1.45 mm to 1.5 mm. The excellent electromagnetic wave absorption performance of the flexible PVDF/SiCnw/MXene nanocomposites was attributed to the proper impedance matching, enhanced interfacial polarization and high dielectric loss. Thus, this study introduces a simple approach to develop high-efficiency, flexible and lightweight electromagnetic wave absorption materials with a tailored nanostructure.

The rising demands for efficient regulating the intermittency of renewable energies as well as the rapid spread of portable electronics or electric vehicles have put forward higher requirements on future energy storage systems. Based on the electrochemical reaction difference between lithium and anodes/cathodes, a series of lithium-based energy storage systems, including lithium-ion batteries, lithium-sulfur batteries, lithium-ion capacitors and lithium-oxygen batteries, have been developed and inspired increasing research enthusiasm due to their efficient energy storage features. However, from their current development status, there remains an enormous gap in energy/power density, durability and safety issues between the practical and theoretical performance. Fortunately, 2D nanomaterials, which have been widely applied in lithium-based energy storage systems due to some unique physical/chemical properties, are gradually closing the gap. Therefore, the synthesis approaches for targeting 2D nanomaterials with controlled qualities will be of great significance in this field. On the other hand, for better addressing some stubborn issues during the application, it is necessary to modify 2D nanomaterials by some effective functionalization strategies. In this review, we summarize the general synthesis approaches of 2D nanomaterials as well as functionalization strategies for high-performance lithium-based energy storage systems. Furthermore, the specific role of functionalized 2D nanomaterials in lithium energy storage will be pointed out by presenting the recent achievements in this field. A deep understanding of these works will inspire more ideas for designing 2D nanomaterials with superior performance for advanced electrochemical storage systems, including but not limited to lithium energy storage.

Electrochemical CO2 reduction (CO2RR) using renewable energy sources represents a sustainable means of producing carbon-neutral fuels. Unfortunately, low energy efficiency, poor product selectivity, and rapid deactivation are among the most intractable challenges of CO2RR electrocatalysts. Here, we strategically propose a "two ships in a bottle" design for ternary Zn-Ag-O catalysts, where ZnO and Ag phases are twinned to constitute an individual ultrafine nanoparticle impregnated inside nanopores of an ultrahigh-surface-area carbon matrix. Bimetallic electron configurations are modulated by constructing a Zn-Ag-O interface, where the electron density reconfiguration arising from electron delocalization enhances the stabilization of the *COOH intermediate favorable for CO production, while promoting CO selectivity and suppressing HCOOH generation by altering the rate-limiting step toward a high thermodynamic barrier for forming HCOO*. Moreover, the pore-constriction mechanism restricts the bimetallic particles to nanosized dimensions with abundant Zn-Ag-O heterointerfaces and exposed active sites, meanwhile prohibiting detachment and agglomeration of nanoparticles during CO2RR for enhanced stability. The designed catalysts realize 60.9% energy efficiency and 94.1 ± 4.0% Faradaic efficiency toward CO, together with a remarkable stability over 6 days. Beyond providing a high-performance CO2RR electrocatalyst, this work presents a promising catalyst-design strategy for efficient energy conversion.

In the present study, bifunctional fusion proteins were designed by fusing the kringle 2 and protease domains of tissue-type plasminogen activator (tPA) to the C-terminal fragment of hirudin. The thrombolytic and anticoagulant activities of these recombinant proteins from mammalian cells were investigated using in vitro coagulation models and chromogenic assays. The results showed that all assayed tPA mutants retained catalytic activity. The C-terminal fragment of hirudin may have weak affinity to thrombin and thus was insufficient to suppress thrombin-mediated fibrin agglutination. The strength of the thrombolytic activity only relied on the selected tPA sequences, and the fibrinolytic efficiency of single-chain protein significantly decreased. Our data indicate that truncated tPA combined with a hirudin peptide may provide a framework for the further development of a new antithrombotic agent.

The utilization of mildly acidic electrolyte and corresponding Mn salt pairing unlocked a path toward highly rechargeable Zn-MnO2 batteries, but long-term feasibility of these cathode-preserving strategy under practical conditions is never verified. In this study, in-situ MnO2 electrodeposition occurring in the battery recharging process is discovered to be a side reaction that substantially nullifies the practicality of the strategy. Particularly, it is identified to be responsible for irreversibly converting the electrolyte Mn ions to electrochemically passive species and triggering battery performance deterioration. These newfound recognitions lead to the formulation of a kinetic inhibition strategy, which is executed through an unconventional cathode electrode design. Specifically, graphite nanosheets with limited surface defects are incorporated into MnO2 electrodes to hinder the rate determining Mn adsorption process and thus effectively suppress the electrodeposition reaction. The resulting thin film binder-free MnO2 electrodes achieve near-full one-electron capacity reversibly for over 600 cycles, with an average columbic efficiency of ~99.8%. Overall, this study reveals the importance of suppressing MnO2 electrodeposition in Zn-MnO2 batteries and provides a contrasting view on key factors that dictate the stability of the system.

Polymeric carbon nitride (g-C3N4) has emerged as a promising material for energy-related applications. However, the utilization of g-C3N4 in photoelectrochemical cells is still limited by poor exciton mobility, sluggish hole extraction, and short electron diffusion length. Here, we report a molten-based defect engineering strategy to prepare nitrogen-deficient g-C3N4 quantum dots (SxCNQD) for photoelectrochemical water splitting. This novel strategy requires no chemical etching or secondary treatments like recent state-of-the-art defect introduction methods, and for the first time achieves the in-situ integration of nitrogen-vacancy defects (NVs) during the polymerization of g-C3N4. Theoretical evaluation and experimental validation identified that the involved structural NVs redistribute the electrons on the delocalized π-conjugated networks of g-C3N4 and creates an additional sub-band on the optical bandgap, which can effectively improve carrier separation, facilitate charge transport dynamics, and boost hole extraction. Beneficial from its featured topological structures and electronic properties, the S600CNQD@ZnO photoanode exhibits a markedly high photocurrent density of 193.8 μA cm−2 at 1.23 V vs. RHE, long-term durability, as well as an impressive IPCE value in an alkaline solution in the absence of sacrificial agent under visible light illumination.

The implementation of mixed matrix membranes (MMMs) for sub-angstrom scale gas separations remains a grand challenge. Herein, a series of analogous mixed matrix membrane (AMMMs) were constructed via molecular-level hybridization by utilizing a reactive ionic liquid (RIL) as the continuous phase and graphene quantum dots (GQD) as nanofiller for sub-angstrom scale ethylene/ethane (0.416 nm/0.443 nm) separation. With a small number of GQDs (3.5 wt%) embedded in GQD/RIL AMMMs, ethylene permeability soared by 3.1-fold, and ethylene/ethane selectivity simultaneously boosted by nearly 60 % and reached up to 99.5, which outperformed most previously reported state-of-the-art membranes. Importantly, the interfacial pathway structure was visualized and their self-assembly mechanism was revealed, where the non-covalent interactions between RIL and GQDs induced the local arrangement of IL chains to self-assemble into plenty of compact and superfast interfacial pathways, contributing to the combination of superhigh permeability and selectivity.

The thermal stability of polypropylene (PP) materials containing the PP -grafted -maleic -anhydride (PPMA), plasticized cellulose acetate (CA*) and magnesium hydroxide (MH), was investigated. The thermogravimetric analysis (TGA) conducted under air conditions revealed distinct degradation patterns when CA*, MH or MH/CA* were added to PP*. The addition of MH to PP*/CA* improved the thermal stability by shifting the maximum rate of mass loss to a higher temperature. But the MH addition could not counterbalance the lower temperature for the onset of degrada- tion when CA* was blended with PP*. The improved thermal stability of PP*/CA* when MH was added is supported by the higher activation energy (Ea) of the MH/CA*/PP materials. This study also presents a numerical integration method that is recommended to improve the accuracy of Ea estimates from TGA data at multiple heating rates. The results indicate that the combined use of MH and CA* leads to materials with the highest thermal stability.

Stable solid electrolyte interface (SEI) is highly sought after for lithium metal batteries (LMB) owing to its efficient electrolyte consumption suppression and Li dendrite growth inhibition. However, current design strategies can hardly endow a multifunctional SEI formation due to the non-uniform, low flexible film formation and limited capability to alter Li nucleation/growth orientation, which results in unconstrained dendrite growth and short cycling stability. Herein, we present a novel strategy to employ electrolyte additives containing catechol and acrylic groups to construct a stable multifunctional SEI by in-situ anionic polymerization. This self-smoothing and robust SEI offers multiple sites for Li adsorption and steric repulsion to constrain nucleation/growth process, leading to homogenized Li nanosphere formation. This isotropic nanosphere offers non-preferred Li growth orientation, rendering uniform Li deposition to achieve a dendrite-free anode. Attributed to these superiorities, a remarkable cycling performance can be obtained, i.e., high current density up to 10 mA cm−2, ultra-long cycle life over 8500 hrs operation, high cumulative capacity over 4.25 Ah cm−2 and stable cycling under 60 °C. A prolonged lifespan can also be achieved in Li-S and Li-LiFePO4 cells under lean electrolyte content, low N/P ratio or high temperature conditions. This facile strategy also promotes the practical application of LMB and enlightens the SEI design in related fields., Stable solid electrolyte interface (SEI) is heavily investigated due to its role in improving lithium metal batteries. Here, the authors present a new strategy by employing electrolyte additives to construct stable multifunctional SEI via in situ anionic polymerization.

The emerging applications of electrochemical gas sensors (EGSs) in Internet of Things-enabled smart city and personal health electronics bring out a new challenge for common EGSs, such as alcohol fuel cell sensors (AFCSs) to reduce the dependence on a pricy Pt catalyst. Here, for the first time, we propose a low-cost novel N,S-codoped metal catalyst (FeNSC) to accelerate oxygen reduction reaction (ORR) and replace the Pt catalyst in the cathode of an AFCS. The optimal FeNSC shows high ORR activity, stability, and alcohol tolerance. Furthermore, the FeNSC-based AFCS not only demonstrates excellent linearity, low detection limit, high stability, and superior sensitivity to that of the commercial Pt/C-based AFCS but also outperforms commercial Pt/C-based AFCS in the exposed cell regarding great linearity, high sensitivity, and great stability. Such a promising sensor performance not just proves the concept of the FeNSC-based ACFS but enlightens the next-generation designs toward low-cost, highly sensitive, and durable EGSs.

Zinc-iodine redox flow batteries (ZIFBs) have emerged as promising energy storage systems due to their high-energy density. However, their practical use has been limited by their poor stability, low efficiency and high cost. In this work, we implemented a novel strategy to improve the performance and cyclability of ZIFBs, as well as decrease the chemical cost, by developing and utilizing ammonium-based electrolytes. An ammonium chloride supported zinc-iodine redox flow battery (AC-ZIFB) based on the ammonium iodide/triiodide redox couple was designed, and it achieved a high energy density of 137 Wh L -1 , Coulombic efficiency of ~99%, energy efficiency of ~80%, and a cycle-life of 2500 cycles at a 11-times lower chemical cost than conventional ZIFBs. Such improvements are mainly attributed to the multifunctional roles of cost-effective chemicals utilized in a new decoupled electrolyte design, which mitigates zinc dendrite formation, facilitates anodic and cathodic reaction kinetics and unlocks extra capacity with the primary aid of I 2 C l − formation. This straightforward, yet effective strategy, empowers the AC-ZIFB with excellent potential as a robust and practical redox flow battery and more broadly demonstrates a facile strategy of using multifunctional electrolyte chemistry to achieve a reliable, high-performance, and cost-competitive energy storage system.

Summary Polysulfide retention and catalysis are currently among the most important factors toward solving much of the technical challenges of lithium-sulfur (Li-S) batteries. Taking advantage of the electronic structure specific to tantalum, we explore the application of amorphous tantalum oxide with oxygen vacancies embedded inside a microporous carbon matrix as an electrocatalyst for the Li-S system. Through a pore-constriction mechanism, the dimensions of tantalum oxide are controlled to be nanosized with abundant polysulfide-retaining and catalytically active sites. High cycle and rate performances were achieved at practically relevant sulfur loadings and electrolyte content. We believe our identification of tantalum as a new catalyst material for Li-S batteries will incite more investigation into the specific selection of transition metals based on their electronic structures. Meanwhile, the “ship in a bottle” strategy will enlighten the structure design for energy conversion and storage systems.

Pt-based electrocatalysts are considered as one of the most promising choices to facilitate the oxygen reduction reaction (ORR), and the key factor enabling their success is to reduce the required amount of platinum. Herein, we focus on illuminating both the theoretical mechanisms which enable enhanced and sustained ORR activity and the practical methods to achieve them in catalysts. The various multi-step pathways of ORR are firstly reviewed and the rate-determining steps based on the reaction intermediates and their binding energies are analyzed. We then explain the critical aspects of Pt-based electrocatalysts to tune oxygen reduction properties from the viewpoints of active sites exposure and altering the surface electronic structure, and further summarize representative research progress towards practically achieving these activity enhancements with a focus on platinum size reduction, shape control and core Pt elimination methods. We finally outline the remaining challenges and provide our perspectives with regard to further enhancing their activities.

The notorious shuttling behaviors and sluggish conversion kinetics of the intermediate lithium polysulfides (LPS) are hindering the practical application of lithium sulfur (Li-S) batteries. Herein, an ultrafine, amorphous, and oxygen-deficient niobium pentoxide nanocluster embedded in microporous carbon nanospheres (A-Nb2O5-x@MCS) was developed as a multifunctional sulfur immobilizer and promoter toward superior shuttle inhibition and conversion catalyzation of LPS. The A-Nb2O5-x nanocluster implanted framework uniformizes sulfur distribution, exposes vast active interfaces, and offers a reduced ion/electron transportation pathway for expedited redox reaction. Moreover, the low crystallinity feature of A-Nb2O5-x manipulates the LPS chemical affinity, while the defect chemistry enhances the intrinsic conductivity and catalytic activity for rapid electrochemical conversions. Attributed to these superiorities, A-Nb2O5-x@MCS delivers good Li-S battery performances, that is, high areal capacity of 6.62 mAh cm-2 under high sulfur loading and low electrolyte/sulfur ratio, superb rate capability, and cyclability over 1200 cycles with an ultralow capacity fading rate of 0.024% per cycle. This work provides a synergistic regulation on crystallinity and oxygen deficiency toward rapid and durable sulfur electrochemistry, holding a great promise in developing practically viable Li-S batteries and enlightening material engineering in related energy storage and conversion areas.

In this study, three types of amine-functionalized graphene oxide (f-GO) have been synthesized and their polyurethane (PU) composites have been fabricated. Mechanical properties and the anticorrosion performance of as-prepared composites were thoroughly investigated. The amine groups (two aliphatic groups and one aromatic group) on GO influenced the dispersion of the fillers and the properties of the composites. Among the f-GO series, GO functionalized with 2-naphthyl amine (2NA-GO) indicated higher mechanical properties and corrosion resistance than other PU composites. Specifically, the incorporation of 0.5 wt % of 2NA-GO in the PU matrix showed a 2.2 times higher tensile modulus than the neat PU and the highest protection efficiency of 99.94%. This synergetic effect of 2NA-GO was due to the aromatic structure and relatively low molecular weight of 2NA. The aromatic structure developed π–π interfacial interactions between the amine group and phenyl groups of the hard segments in the PU backbone. Furthermore, the lower molecular weight contributed to the uniform dispersion of the filler. Based on the results, molecular structure and molecular weight could be a critical factor in designing the f-GO to improve the mechanical and corrosion properties of PU composites. Additionally, this fact can be contributed to PU industries, which require a high anticorrosion performance as well as enhanced mechanical properties.

Rational regulation on polysulfide behaviors is of great significance in pursuit of reliable solution-based lithium-sulfur (Li-S) battery chemistry. Herein, we develop a unique polymeric zwitterion (PZI) to establish a smart polysulfide regulation in Li-S batteries. The zwitterionic nature of PZI integrates sulfophilicity and lithiophilicity in the matrix, fostering an ionic environment for selective ion transfer through the chemical interactions with lithium polysulfides (LiPS). When implemented as a functional interlayer in the cell configuration, PZI empowers strong obstruction against polysulfide permeation but simultaneously allows fast Li+ conduction, thus contributing to significant shuttle inhibition as well as the resultant facile and stable sulfur electrochemistry. The PZI-based cells realize excellent cyclability over 1000 cycles with a minimum capacity fading rate of 0.012% per cycle and favorable rate capability up to 5 C. Moreover, a high areal capacity retention of 5.3 mAh cm-2 after 300 cycles can be also obtained under raised sulfur loading and limited electrolyte, demonstrating great promise in developing high-efficiency and long-lasting Li-S batteries.

Worldwide trends in mobile electrification, largely driven by the popularity of electric vehicles (EVs) will skyrocket demands for lithium‐ion battery (LIB) production. As such, up to four million metric tons of LIB waste from EV battery packs could be generated from 2015 to 2040. LIB recycling directly addresses concerns over long‐term economic strains due to the uneven geographic distribution of resources (especially for Co and Li) and environmental issues associated with both landfilling and raw material extraction. However, LIB recycling infrastructure has not been widely adopted, and current facilities are mostly focused on Co recovery for economic gains. This incentive will decline due to shifting market trends from LiCoO2 toward cobalt‐deficient and mixed‐metal cathodes (eg, LiNi1/3Mn1/3Co1/3O2). Thus, this review covers recycling strategies to recover metals in mixed‐metal LIB cathodes and comingled scrap comprising different chemistries. As such, hydrometallurgical processes can meet this criterion, while also requiring a low environmental footprint and energy consumption compared to pyrometallurgy. Following pretreatment to separate the cathode from other battery components, the active material is dissolved entirely by reductive acid leaching. A complex leachate is generated, comprising cathode metals (Li+, Ni2+, Mn2+, and Co2+) and impurities (Fe3+, Al3+, and Cu2+) from the current collectors and battery casing, which can be separated and purified using a series of selective precipitation and/or solvent extraction steps. Alternatively, the cathode can be resynthesized directly from the leachate.

The development of robust and cost-effective bifunctional oxygen electrocatalysts is of significant importance for the widespread implementation of Zn–air batteries yet remains an immense challenge, which calls for the molecular-level manipulation of active species as well as morphology engineering to accelerate the reversible oxygen reaction dynamics. Herein, a “trimurti” heterostructured cobalt-based hybrid is designed by a facile, one-step phosphorization of layered Co-hexamine metal–organic frameworks. The synergistic effect between cobalt phosphides (Co2P and CoP) and cobalt oxide significantly boosts the electrocatalytic activity of the oxygen redox reaction. Besides, the hierarchically porous structure promotes the accessibility of active species and smooth electron/reactant transportation. Due to these attributes, the as-developed electrocatalyst outperforms the state-of-art non-noble metal catalysts and even noble metal benchmarks with a half-wave potential of 0.86 V for the ORR and an overpotential of 0.37 V at 10 mA cm−2 for the OER. Furthermore, an appealing catalytic performance is also demonstrated in an assembled Zn–air battery, which displays a lower voltage gap of 0.86 V and improved cyclability of 202 h. This work not only affords a competitive bifunctional oxygen electrocatalyst for Zn–air batteries but also highlights the synergetic effect from heterointerfaces in electrocatalysis.

Hollow porous prismatic graphitic carbon nitride with nitrogen vacancies and oxygen doping was successfully constructed using dicyandiamidine as the only raw material via a facile two-step strategy of a low-temperature hydrothermal method followed by a subsequent calcination process. The as-obtained graphitic carbon nitride showed a hollow prismatic morphology with loose spongy-like walls, a hierarchical pore structure, and a specific surface area of 220.16 m2 g-1. Such graphitic carbon nitride exhibited an ultrahigh nitrogen fixation rate of 118.8 mg L-1 h-1 gcat-1 under visible light irradiation and showed excellent stability during the reactions. A possible mechanism for photocatalytic nitrogen fixation on the catalyst was proposed as follows: under visible-light irradiation, graphitic carbon nitride with nitrogen vacancies and oxygen doping underwent charge separation to generate electron-hole pairs, and then the photogenerated electrons on the conduction band were quickly transferred to the nitrogen vacancy induced mid-gap state; consequently, the trapped electrons reacted with the activated nitrogen on the nitrogen vacancies to produce ammonia. The significant enhancement in the photocatalytic nitrogen fixation performance of graphitic carbon nitride can be attributed to its unique hollow prismatic morphology with a loose porous structure, fully exposed active sites of nitrogen vacancies, more negative conduction band, suitable visible-light response and the efficient separation of photogenerated electron-hole pairs.

A unique zinc–hexamethylenetetramine coordination complex (ZnHMT) has been developed through a facile and fast solution-based method. The ZnHMT complex delivers an exquisite flower-like nanoarchitecture assembled by ultrathin nanosheets, which not only facilitates the electrolyte infiltration and ion transfer, but also implements efficient exposure of active interfaces. Meanwhile, the strong chemical interactions between ZnHMT and polysulfides render potent sulfur immobilizations, contributing to effective inhibition of the shuttling behavior. As a result, Li–S cells with a ZnHMT-based interlayer achieve excellent cyclability over 1000 cycles, superb rate capability up to 5C and a high areal capacity of 5.9 mA h cm−2 under raised sulfur loading.

Structure engineering is an effective way to substantially adjust the chemical and physical properties of materials. However, the effects of structure engineering of carbon hosts on the catalytic p...

Lithium anode‐based batteries (LBs) are highly demanded in society owing to the high theoretical capacity and low reduction potential of metallic lithium. They are expected to see increasing deployment in performance critical areas including electric vehicles, grid storage, space, and sea vehicle operations. Unfortunately, competitive performance cannot be achieved when LBs operating under extreme temperature conditions where the lithium‐ion chemistry fail to perform optimally. In this review, a brief overview of the challenges in developing LBs for low temperature (60 °C) operation are provided followed by electrolyte design strategies involving Li salt modification, solvation structure optimization, additive introduction, and solid‐state electrolyte utilization for LBs are introduced. Specifically, the prospects of using lithium metal batteries (LMBs), lithium sulfur (Li‐S) batteries, and lithium oxygen (Li‐O2) batteries for performance under low and high temperature applications are evaluated. These three chemistries are presented as prototypical examples of how the conventional low temperature charge transfer resistances and high temperature side reactions can be overcome. This review also points out the research direction of extreme temperature electrolyte design toward practical applications., This review introduces current progress of electrolyte design in lithium metal batteries to realize improved performance under extremely low and high temperature applications. By reviewing the scientific issues related to the current electrolyte design strategy, including Li salt modification, solvent component optimization, electrolyte additive introduction and solid‐state electrolyte utilization, this review points out the research direction toward practical applications.

A BN membrane with a distinct nanoconfinement effect toward efficient ethylene/ethane separation is presented. The horizontal and inclined self-assembly of 2D BN nanosheets endow the BN membrane with abundant percolating nanochannels, and these nanochannels are further decorated by reactive ionic liquids (RILs) to tailor their sizes as well as to achieve nanoconfinement effect. The noncovalent interactions between RIL and BN nanosheets favor the ordered alignment of the cations and anions of RIL within BN nanochannels, which contributes to a fast and selective ethylene transport. The resultant membranes exhibit an unprecedented separation performance with superhigh C2 H4 permeance of 138 GPU and C2 H4 /C2 H6 selectivity of 128 as well as remarkably improved long-term stability for 180 h, outperforming reported state-of-the-art membranes.

Currently, most catalysts for hydrogenation of p-nitrophenol employ the size- and shape-controlled noble metal (Au, Ag, Pd and Pt, etc.) nanomaterials or which supported on appropriate supports. Nevertheless, their high prices and low reserves severely limit the industrial application. Here we report a metal-free catalyst of porous crimped graphitic carbon nitride, which is prepared by calcining dicyandiamidine (a new precursor). This catalyst possesses abundant amino groups on the terminal edges of in-planar tri-s-triazine ring and large specific surface area, thus exhibits extremely high catalytic activity for catalytic hydrogenation of p-nitrophenol in the presence of NaBH4, which can be equivalent to (or even higher than) those of the previously reported noble metal-based catalysts. Interestingly, the kinetics analysis of hydrogenation of p-nitrophenol to p-aminophenol shows that the reaction follows the zero-order kinetics, different from the pseudo-first-order kinetics for the hydrogenation over the noble metal-based catalysts. In fact during reaction process, the catalytic oxidation of BH4− and the generation of hydride ion (H−) occur on the catalyst surface, while the hydrogenation process of p-nitrophenol proceeds in the bulk solution. This work establishes a new understanding of the hydrogenation process of p-nitrophenol using the metal-free catalyst based on graphitic carbon nitride.

Batteries with conversion-type electrodes exhibit higher energy storage density but suffer much severer capacity fading than those with the intercalation-type electrodes. The capacity fading has been considered as the result of contact failure between the active material and the current collector, or the breakdown of solid electrolyte interphase layer. Here, using a combination of synchrotron X-ray absorption spectroscopy and in situ transmission electron microscopy, we investigate the capacity fading issue of conversion-type materials by studying phase evolution of iron oxide composited structure during later-stage cycles, which is found completely different from its initial lithiation. The accumulative internal passivation phase and the surface layer over cycling enforce a rate−limiting diffusion barrier for the electron transport, which is responsible for the capacity degradation and poor rate capability. This work directly links the performance with the microscopic phase evolution in cycled electrode materials and provides insights into designing conversion-type electrode materials for applications., Conversion electrodes possess high energy density but suffer a rapid capacity loss over cycling compared to their intercalation equivalents. Here the authors reveal the microscopic origin of the fading behavior, showing that the formation and augmentation of passivation layers are responsible.

Efficient energy storage systems based on rechargeable lithium-ion batteries (LIBs) represent the most leading technology in the field of portable devices market. Nanostructured electrode materials possess compelling opportunities for high-performance LIBs, but it's still the main challenge to ensure the structural integrity of the electrodes over harsh discharge-recharge cycles. Here, we present a general approach, combining self-assembly process, in-situ substitution, and thermal annealing, for the fabrication of a 3D heteroarchitecture built from nanosized spinel ferrites (MFO, denoted as MFe2O4, M = Mn, Ni, Cu, Co) and graphitic carbon nitride covalently functionalized nitrogen-doped graphene (CN-NG). This typical 3D architecture could possess a series of distinctive structural advantages, including: (i) sufficient hierarchical pores and channels for the rapid access of electrolytes, (ii) plentiful topological defects introduced by lamellar g-C3N4 nanoflakelets for the ultrafast absorption and diffusion of lithium ions, (iii) incorporation of structural nitrogen in graphene to modulate the electronic structure for boosting the electron transport and providing extra mechanism for lithium storage, (iv) uniformly distributed MFO nanoparticles with large amounts of active centers and high reversible capacities, (v) strong covalent C-N bonding and metal-support interaction for guaranteeing the long-term electrochemical cyclability, all of which are conducive to accelerating the improvement of lithium storage properties. As a consequence, significantly high reversible capacities of 1032, 919, 1008, and 1105 mAh g−1 are obtained for 3D MnFe2O4/CN-NG(0.4), 3D NiFe2O4/CN-NG(0.4), 3D CoFe2O4/CN-NG(0.4), and 3D CuFe2O4/CN-NG(0.4), respectively, at a current density of 0.1 A g−1. Especially, 3D MnFe2O4/CN-NG(0.4) presents a capacity retention of 73% at a high current density of 1 A g−1 even after 800 cycles, as well as excellent rate capability and reliable long-term cycling stability. It is anticipated that the synthetic strategy present here can be further extended to the construction of various 3D heteroatom-doped carbonaceous nanomaterials that contain metals or metal oxides, which offers new possibilities in the fabrication of advanced supports for maximum utilization, alleviating volume variation and the particle fracture of active materials in LIBs.

Achieving an optimal surface structure and adequate carbon distribution is an important criterion for transition metal oxide/carbon composites targeted for supercapacitor applications. In this study, a one-step hydrothermal reaction is developed to incorporate graphene quantum dots (GQDs) and MnCo2O4.5 with GQDs serving as both a conductive filling material and structure inducing agent. The process is fine-tuned based on GQD quantities to generate various morphologies including nanospheres, nanoneedles and nanoarrays. And a mechanism is proposed to explain the roles of GQDs in triggering the structural transformation. Among the different structures, the nanoneedle composites (denoted as MCO-40 GQDs) exhibit an apparent porous structure and even GQD distribution, which establishes a conductive network that provides excellent charge transfer capability for optimal electrochemical performances. As a result, the MCO-40 GQD nanoneedle electrode delivers the largest capacitance of 1625 F g−1 at 1 A g−1, which is four times higher than the capacitance of a pure MnCo2O4.5 nanosphere electrode (368 F g−1 at 1 A g−1). Moreover, the asymmetric supercapacitor fabricated with MCO-40 GQDs and reduced graphene oxide exhibits long cycle stability and a high energy density of 46 Wh kg−1 at a power density of 66 W kg−1, surpassing all previously reported capacitive devices based on MnCo2O4.5. Overall, this study illustrates the exciting roles of GQDs in material synthesis as a structure inducing agent and provides for the first time a reference for constructing MnCo2O4.5 based advanced nanomaterials with various shapes for energy storage applications.

In this work, three-dimensional ordered mesoporous titanium nitride (3DOM-TiN) has been synthesized via a templating method as a novel high-performance non-carbon capacitive deionization (CDI) electrode material. The dual ion electrosorption mechanisms, fast ion diffusion and rapid charge transfer enabled by the multiple advantageous features of the 3DOM-TiN electrode facilitate an outstanding CDI salt adsorption capacity (SAC) as high as 23.6 mg g−1 and a record-breaking maximum salt adsorption rate (SAR) of 3.2 mg g−1 min−1 in 500 mg L−1 NaCl solution at an applied voltage of 1.2 V. Such excellent CDI performance in addition to excellent cycling stability not only ranks the 3DOM-TiN electrode as one of the most promising electrodes for future CDI applications but also confirms the great potential of nanoengineered non-carbon electrodes for next-generation CDI cells.

A graphene oxide (GO) membrane is an ideal separator for multiple applications due to its morphology, selectivity, controllable oxidation, and high aspect ratio of the 2D nanosheet. However, the anisotropic ion conducting nature caused by its morphology is not favorable toward through-plane conductivity, which is vital for solid-state electrolytes in electrochemical devices. Here, we present a strategy to selectively enhance the through-plane proton conductivity of a GO membrane by reducing its degree of anisotropy with pore formation on the nanosheets through the sonication-assisted Fenton reaction. The obtained porous GO (pGO) membrane is a near-isotropic, proton-conducting GO membrane, showing a degree of anisotropy as low as 2.77 and 47% enhancement of through-plane proton conductivity as opposed to the pristine GO membrane at 25 °C and 100% relative humidity. The anisotropic behavior shows an Arrhenius relationship with temperature, while the water interlayer formation between nanosheets plays a pivotal role in the anisotropic behavior under different values of relative humidity (RH); that is, as low RH increases, water molecules tend to orient in a bimodal distribution clinching the nanosheets and forming a subnanometer, high-aspect-ratio, water interlayer, resulting in its peak anisotropy. Further increase in RH fills the interlayer gap, resulting in behaviors akin to near-isotropic, bulk water. Lastly, implementation of the pGO membrane, as the solid proton-conductive electrolyte, in an alcohol fuel cell sensor has been demonstrated, showcasing the excellent selectivity and response, exceptional linearity, and ethanol detection limits as low as 25 ppm. The amalgamation of excellent performance, high customizability, facile scalability, low cost, and environmental friendliness in the present method holds considerable potential for transforming anisotropic GO membranes into near-isotropic ion conductors to further membrane development and sensing applications.

All-solid-state lithium ion batteries (ASSLBs) are considered next-generation devices for energy storage due to their advantages in safety and potentially high energy density. As the key component in ASSLBs, solid-state electrolytes (SSEs) with non-flammability and good adaptability to lithium metal anodes have attracted extensive attention in recent years. Among the current SSEs, composite solid-state electrolytes (CSSEs) with multiple phases have greater flexibility to customize and combine the advantages of single-phase electrolytes, which have been widely investigated recently and regarded as promising candidates for commercial ASSLBs. Based on existing investigations, herein, we present a comprehensive overview of the recent developments in CSSEs. Initially, we introduce the historical development from solid-state ionic conductors to CSSEs, and then summarize the fundamentals including mechanisms of lithium ion transport, key evaluation parameters, design principles, and key materials. Four main types of advanced structures for CSSEs are classified and highlighted according to the recent progress. Moreover, advanced characterization and computational simulation techniques including machine learning are reviewed for the first time, and the main challenges and perspectives of CSSEs are also provided for their future development.

The practical application of lithium-sulfur (Li-S) batteries is hindered by the "shuttle" of lithium polysulfides (LiPS) and sluggish Li-S kinetics issues. Herein, a synergistic strategy combining mesoporous architecture design and defect engineering is proposed to synthesize multifunctional defective 3D ordered mesoporous cobalt sulfide (3DOM N-Co9 S8- x ) to address the shuttling and sluggish reaction kinetics of polysulfide in Li-S batteries. The unique 3DOM design provides abundant voids for sulfur storage and enlarged active interfaces that reduce electron/ion diffusion pathways. Meanwhile, X-ray absorption spectroscopy shows that the surface defect engineering tunes the CoS4 tetrahedra to CoS6 octahedra on Co9 S8 , endowing abundance of S vacancies on the Co9 S8 octahedral sites. The ever-increasing S vacancies over the course of electrochemical process further promotes the chemical trapping of LiPS and its conversion kinetics, rendering fast and durable Li-S chemistry. Benefiting from these features, the as-developed 3DOM N-Co9 S8- x /S cathode delivers high areal capacity, superb rate capability, and excellent cyclic stability with ultralow capacity fading rate under raised sulfur loading and low electrolyte content. This design strategy promotes the development of practically viable Li-S batteries and sheds lights on the material engineering in related energy storage application.

The implementation of pristine metal-organic frameworks as air electrode may spark fresh vitality to rechargeable zinc-air batteries, but successful employment is rare due to the challenges in regulating their electronic states and structural porosity. Here we conquer these issues by incorporating ligand vacancies and hierarchical pores into cobalt-zinc heterometal imidazole frameworks. Systematic characterization and theoretical modeling disclose that the ligand editing eases surmountable energy barrier for *OH deprotonation by its efficacy to steer metal d-orbital electron occupancy. As a stride forward, the selected cobalt-zinc heterometallic alliance lifts the energy level of unsaturated d-orbitals and optimizes their adsorption/desorption process with oxygenated intermediates. With these merits, cobalt-zinc heterometal imidazole frameworks, as a conceptually unique electrode, empowers zinc-air battery with a discharge-charge voltage gap of 0.8 V and a cyclability of 1250 h at 15 mA cm–2, outperforming the noble-metal benchmarks., Low intrinsic activity and accessibility of active sites limit the application of metal-organic framework as catalyst for Zn-air battery. Here, authors present a cation substitution strategy to regulate the electronic state of metal sites and modify its porosity, which enables battery operation.

Carbon materials possessing porous structure as well as high heteroatom doping content gradually become critical components in various electrochemical storage applications. Here, a facile route based on boric acid catalysis synthesis process was proposed to prepare hierarchical boron-doped graphene sponge. The hydrolyzed intermediate B(OH)+4 from boric acid acts as porous forming agent precisely making contribution to the macro-porous structure of graphene. Benefiting from unique structure and boron doping (2.4%), the obtained graphene sponge exhibits a significant improvement in capacitance (369.2 F g−1 at 2 A g−1) and maintains an outstanding rate capability (174.9 F g−1 at 30 A g−1). After 1500 cycles at 5 A g−1, the sponge electrode still possesses 91.7% of capacitance retention, revealing the promising future as a high-performance electrode material for supercapacitors.

Polypropylene (PP) is incorporated with four different grades (H100, M25, M5, and C300) of graphene nanoplatelets (GnPs) via twin screw extrusion followed by injection moulding. The composites’ thermal stability, crystallization behaviour, tensile strength, and electrical property are carefully examined. The thermal stability is significantly enhanced with the incorporation of small-sized GnPs as shown by the 11.2% improvement in T5% (the temperature at which 5 wt% of the mass loss occurs) and 5.1% improvement in Tmax (the temperature at which the maximum loss rate occurs). The thermal stabilizing effect of fillers can be significantly enhanced when they are well distributed with less aggregation as is the case for small-sized GnPs. The GnPs show a considerable nucleating effect on PP by increasing the crystallization temperature (Tc). The greatest improvement in tensile property is achieved with the use of small-sized GnPs. A 33.0% enhancement in tensile strength and 59.1% improvement of tensile modulus are obtained with the use of C300 and M5, respectively. The significantly increased thermal stability and mechanical property with small-sized GnPs are due to the fact that these smallsized fillers achieve a high degree of dispersion with less agglomeration as shown in the scanning electron microscope (SEM) images. However, the fillers with a large sheet size are still beneficial for purposes concerning electrical conductivity since the lowest percolation is obtained with H100. The greater the size of the GnPs, the smaller the percolation threshold of composites is exhibited.

In this work, Ni-Co chalcogenides with controllable amorphous structure were successfully grown on carbon cloth via a facile surfactant-assisted hydrothermal route. The interacted reaction between NiCo2(OH)6 precursor and thioacetamide plays a critical role in altering the morphology and crystal structure of Ni-Co chalcogenides. The varying active sites in NiCo2(OH)6 and the H2S gas decomposed from thioacetamide are found to be the key factors for the formation of amorphous Ni-Co chalcogenides. By benefiting from the amorphous structure and hybrid nanosheet morphology, the as-prepared Ni-Co chalcogenides delivers a specific capacitance of 2361.5 F g−1 while retaining 75.8% of its highest capacitance over 2000 cycles at 20 A g−1. The crystallized NiCo2S4 possesses excellent cycling stability but low specific capacitance. This work paves a promising and simple way for precise synthesis amorphous/crystal metal chalcogenides as active materials in aqueous supercapacitors and other high-performance energy storage devices.

In order to improve the mechanical properties of single-base propellant with high nitrogen content, 3% by weight of n-butyl acetate was added as an auxiliary solvent to the alcohol ketone mixed solvent to plasticize the high-nitrogen nitrocellulose in the propellant preparation. The test results of mechanical properties and combustion performance showed that the addition of n-butyl acetate significantly improved the mechanical properties of highnitrogen single-base propellant, but reduced some energy. Therefore, 3%wt of RDX was then added to compensate for this energy loss. The test results showed that the propellant finally obtained maintained its energy, and its impact strength at -40℃ was increased by 10.29% compared with the original sample.

Intermittent, fluctuational, and unpredictable features of renewable energy require grid-level energy storage (GES). Among various types of GES, aqueous electrochemical storage is undoubtedly the most promising method due to its high round-trip efficiency, long cycle life, low cost and high safety. As the most encouraging candidate for aqueous electrochemical storage, aqueous rocking-chair batteries have been heavily investigated. Recently, intercalation-type aqueous batteries beyond the limits of Li+ and Na+ have caught researchers’ attention due to potentially higher capacity and better cyclability, and the number of publications in this nascent field since 2015 has dramatically increased. Therefore, it is highly demanded to summarize what have been learned in this field. In this first comprehensive review paper, we summarize these novel intercalation-type electrode materials and provide perspectives of opportunities and challenges for future research.

International audience; Phosphorus incorporation into carbon can greatly modify its chemical, electronic, and thermal stability properties. To date this has been limited to low levels of phosphorus. Now a simple, large‐scale synthesis of carbon–nitrogen–phosphorus (CNP) materials is reported with tunable elemental composition, leading to excellent thermal stability to oxidation and fire‐retardant properties. The synthesis consists of using monomers that are liquid at high temperatures as the reaction precursors. The molten‐state stage leads to good monomer miscibility and enhanced reactivity at high temperatures and formation of CNP materials with up to 32 wt % phosphorus incorporation. The CNP composition and fire‐retardant properties can be tuned by modifying the starting monomers ratio and the final calcination temperature. The CNP materials demonstrate great resistance to oxidation and excellent fire‐retardant properties, with up to 90 % of the materials preserved upon heating to 800 °C in air.

In this work, a compressible melamine-based carbon/reduced graphene oxide foam was synthesized using a simple one-step process. The nitrogen-rich melamine allows the final composite material to be rich in nitrogen, resulting in a higher conductivity and performance. The synergistic combination of nitrogen-doped carbon foam and reduced graphene oxide results in a compressible, free-standing, binder-free electrode with a capacity of 330 mAh g−1 at 0.1 mA g−1 that can be used in both Lithium-ion Hybrid Supercapacitors (LIHSs) and Lithium-ion Batteries (LIBs). The composite electrode can also be used as a current collector and scaffolding for other active materials. As a proof of concept, a LIHS was fabricated using the composite foam as a free-standing electrode in the anode and a current collector for activated carbon in the cathode. The resulting device has an energy density of 40 Wh kg−1 at 1 A that can be maintained for 800 charge and discharge cycles.

Lithium–sulfur battery possesses high energy density but suffers from severe capacity fading due to the dissolution of lithium polysulfides. Novel design and mechanisms to encapsulate lithium polysulfides are greatly desired by high-performance lithium–sulfur batteries towards practical applications. Herein, we report a strategy of utilizing anthraquinone, a natural abundant organic molecule, to suppress dissolution and diffusion of polysulfides species through redox reactions during cycling. The keto groups of anthraquinone play a critical role in forming strong Lewis acid-based chemical bonding. This mechanism leads to a long cycling stability of sulfur-based electrodes. With a high sulfur content of ~73%, a low capacity decay of 0.019% per cycle for 300 cycles and retention of 81.7% over 500 cycles at 0.5 C rate can be achieved. This finding and understanding paves an alternative avenue for the future design of sulfur–based cathodes toward the practical application of lithium–sulfur batteries., Novel cathode design holds the key to enabling high performance lithium-sulfur batteries. Here the authors utilize anthraquinone to chemically stabilize polysulfides, revealing that the keto groups of anthraquinone play a critical role in forming strong Lewis acid-based chemical bonding.

The rational design of cathode host materials is significant in fulfilling high-efficiency sulfur electrochemistry as well as boosting the energy density of lithium–sulfur (Li–S) batteries. Herein, we develop a stringed “tube on cube” nanohybrid (CPZC) with a ternary hierarchical architecture, which contains a fibrous carbon skeleton, highly porous carbon cube filler, and abundant CNT tentacles as an advanced matrix for sulfur electrodes. The as-developed CPZC delivers excellent conductivity, abundant active interfaces, and strong confinement to polysulfide, and thus is capable of significantly expediting the sulfur redox kinetics and promoting battery durability. The fabricated sulfur electrode achieves a superb rate capability up to 10C, outstanding cyclability over 2000 cycles, and more importantly, excellent performance under high a sulfur loading and sparing electrolyte with a high energy density of 348.8 W h kg−1 and 327.6 W h L−1 at the system level, which reveals its potential in promoting the practical application of Li–S batteries.

Background/Aims: This study aims to predict the pro-angiogenic functions of monocytic-type myeloid-derived suppressor cells (M-MDSCs) derived from mice infected with Echinococcus granulosus. Methods: M-MDSCs were collected from Balb/c mice infected with E. granulosus and normal mice (control) and cultured in vitro. Human umbilical vein endothelial cells (HUVECs) were stimulated with the cell supernatant, and angiogenesis was investigated and analysed by the Angiogenesis module of the software NIH Image J. RNA was extracted from fresh isolated M-MDSCs and analysed with miRNA microarray; differentially expressed miRNAs and their potential functions were analysed through several bioinformatics tools. Finally, quantitative PCR was used to confirm the results of microarray analysis. Results: M-MDSCs from mice infected with E. granulosus could promote the formation of tubes from HUVECs in vitro. Moreover, vascular endothelial growth factor (VEGF) showed significantly high expression, whereas soluble fms-like tyrosine kinase-1 (sFlt-1) showed low expression at the transcriptional level in M-MDSCs from mice infected with E. granulosus. Microarray analysis of miRNAs showed that 28 miRNAs were differentially expressed in M-MDSCs from the two experimental mice groups, and 272 target genes were predicted using the microRNA databases TargetScan, PITA and microRNAorg. These target genes were mainly involved in the biological processes of intracellular protein transport, protein targeting to the lysosome and protein transport, and mainly located in the cytoplasm, neuronal cell body and membrane. Moreover, they were mainly involved in the molecular functions of protein binding, metal ion binding and SH3 domain binding. Further, the differentially expressed miRNAs were mainly enriched in the endocytosis, Wnt and axon guidance pathways, as well as the MAPK, focal adhesion, PI3K-Akt, cAMP, mTOR and TGF-β signalling pathways, which are linked to immunoregulation and angiogenesis based on the results of bioinformatics analysis with DIANA-miRPath 3.0. In addition, the expression of eight miRNAs was randomly verified by quantitative PCR independently in three mice infected with E. granulosus and three normal mice. Conclusion: M-MDSCs have a potential angiogenic role during E. granulosus infection, and miRNAs may play a role in the immune response and angiogenesis functions of M-MDSCs through regulation of the identified signalling pathways.

Development of metal-free carbon-based electrocatalysts with high-efficiency and excellent durability towards both oxygen and hydrogen evolution reactions (OER and HER) in a single electrolyte system is crucial yet challenging for sustainable energy generation. In this work, we report a facile and scalable strategy for fabricating self-supporting boron carbon oxynitride nanofibrous (BCNONF) mats with controllable boron contents via electrospinning and subsequent thermal treatment. Notably, the optimal BCNONF mat affords outstanding OER performance in alkaline electrolyte with low overpotential of 403 mV at 10 mA·cm−2, small Tafel slop of 72.9 mV·dec−1, and high stability (88.1% current density retention after 10 h), outperforming the commercial Ir/C benchmark. Moreover, it can serve as a remarkable HER catalyst with better stability than that of the commercial Pt/C counterpart in the same electrolyte, indicating its bifunctional characteristics. When employed as both anode and cathode of an electrolyzer, the self-supporting BCNONF mats exhibit superior activities with a potential of only 1.79 V at 10 mA·cm−2 and high long-term durability (90.6% current density retention after 50 h) for overall water splitting. Furthermore, density functional theory (DFT) calculations reveal that the remarkable OER and HER bifunctional performance of the BCNONF catalyst are originated from the reduced adsorption strength of O atom and the stronger H* adsorption on the BCNO surface as compared to those on CNO surface, which in turn facilitate efficient interfacial charge transfer between the electrocatalytic intermediates and the BCNONF catalyst.