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Perovskites have shown tremendous promise as functional materials for several energy conversion and storage technologies, including rechargeable batteries, (electro)catalysts, fuel cells, and solar cells. Due to their excellent operational stability and performance, high‐entropy perovskites (HEPs) have emerged as a new type of perovskite framework. Herein, this work reviews the recent progress in the development of HEPs, including synthesis methods and applications. Effective strategies for the design of HEPs through atomistic computations are also surveyed. Finally, an outlook of this field provides guidance for the development of new and improved HEPs. [ABSTRACT FROM AUTHOR]

Featuring high theoretical capacity, environmental friendliness and low cost, lithium‐sulfur (Li‐S) batteries become promising alternatives to satisfy the growing demand for energy storage. To boost their energy density for practical application, modified separators are needed to suppress shuttle effects resulting from the solubility of lithium polysulfides (LiPSs). Herein, we modified traditional polypropylene (PP) separators with functional WS2@C nanoflower composites (WS2@C‐PP). They can effectively adsorb LiPSs and catalyze their conversion on the edge sites of the WS2. Also, the unique construction of a carbon layer coating on the WS2 nanoflowers combines active sites and conducting properties. The material benefits the reversibility of redox reactions and reutilization of active materials. With the WS2@C‐PP separator, the cell displays improved cycling stability and rate performance. When cycling at 0.1 C, the cell discharges a capacity of up to 1475 mAh g−1, and it contributes 943 mAh g−1 originally at 1 C, with a decay rate of only 0.07 % after 500 cycles. Our work highlights the potential of functional separators to advance the properties of Li‐S batteries. [ABSTRACT FROM AUTHOR]

Solid‐state batteries (SSBs) are an emerging technology for safe and high‐energy‐density electrochemical energy storage. Unfortunately, SSBs suffer from inadequate ionic conductivity and sluggish interfacial transport at subzero temperatures, which limit their widespread application. Herein, a flexible, stable, and highly conductive quasi‐solid polymer electrolyte (QSPE) for SSBs is developed that allows low‐temperature (LT) operation. The in situ polymerized QSPE has an integrated battery structure, outstanding ionic conductivity (e.g., 1.0 mS cm−1 at −30 °C), and exhibits favorable compatibility with Li metal (>2000 h in Li|QSPE|Li). Li|QSPE|LiFePO4 and high‐voltage Li|QSPE|LiNi0.8Mn0.1Co0.1O2 batteries demonstrate excellent long‐term stability (>2000 cycles at room temperature) and can operate effectively at LT (e.g., −30 °C). Furthermore, pouch cells with a LiNi0.8Mn0.1Co0.1O2 (14.5 mg cm−2) cathode show flexibility, safety, and high capacity. The high performance of this QSPE is ascribed to its unique multilayer solvation structure that provides fast Li+ transport and excellent interfacial stability. Thus, the newly developed electrolyte chemistry enables practical high‐voltage, LT solid‐state Li batteries. [ABSTRACT FROM AUTHOR]

Li‐ion batteries (LIBs) are the energy storage systems of choice for portable electronics and electric vehicles. Due to the growing deployment of energy storage solutions, LIBs are increasingly required to function safely and steadily over a broad range of operational conditions. However, the conventional electrolytes used in LIBs will malfunction when the temperatures fall below zero or elevate above 60 °C. Further, conventional electrolytes are toxic and flammable, leading to severe safety risks, especially in the case of an accident or overheating. Therefore, an ever‐growing body of research has been dedicated to the development of electrolytes characterized by high ionic conductivity, excellent electrochemical stability, and operability over a wide temperature range. In this Progress Report, the optimization of liquid‐based electrolytes achieved by controlling Li salts, functional additives, and solvents is discussed first. Next, gel‐polymer and all‐solid‐state electrolytes (i.e., ceramics, polymers, and their composites) are presented. Examples of advanced batteries (Li/Na/Zn‐ion batteries and Li‐metal batteries) capable of working over a broad temperature window are highlighted. Morever, recent computational studies aimed at designing and understanding electrolytes are reviewed. Finally, challenges and perspectives regarding emerging electrolyte materials are proposed with the goal of triggering the further development of high‐performance, safe, and wide‐temperature‐operating electrolytes. [ABSTRACT FROM AUTHOR]

Oxygen evolution reaction (OER) is a key reaction for many renewable energy storage and conversion techniques. Developing efficient non‐precious metal‐based electrocatalysts for OER has attracted increasing attention. Herein is reported a strategy to fabricate hierarchical cobalt borate/Ti3C2Tx MXene (Co‐Bi/Ti3C2Tx) hybrid through fast chemical reactions at room temperature. This interesting hierarchical structure of Co‐Bi/Ti3C2Tx hybrid is beneficial for exposing more active sites, improving mass diffusion, and charge‐transfer pathways for electrochemical reaction. Moreover, a strong interaction between Co‐Bi and Ti3C2Tx ensures efficient charge transfer and facilitates the electrostatic attraction of more anionic intermediates for a fast redox process. Consequently, the hierarchical Co‐Bi/Ti3C2Tx hybrid shows extraordinary OER catalytic activity to deliver a current density of 10 mA cm−2 at an overpotential of 250 mV, and a Tafel slope of about 53 mV dec−1. Pushing to the edge: Two‐dimensional Ti3C2Tx supported cobalt borate (Co‐Bi) is a potential catalyst for oxygen evolution reaction in alkaline medium. The Co‐Bi/Ti3C2Tx hybrid displays a hierarchical structure enabling improved exposure of active surface sites, mass diffusion, and charge‐transfer characteristics. Consequently, the hybrid material can deliver a stable current density (10 mA cm−2) at a low overpotential (250 mV). [ABSTRACT FROM AUTHOR]

• Vertically aligned 1 T phase MoS 2 nanosheet array was prepared by a simple method. • Synergistic effect of 1 T phase and unique structure endows outstanding properties. • The cathode shows excellent specific capacity and outstanding cycling stability. • The mechanism was clarified by combining characterizations and DFT calculations. Recently, low-cost and environment-friendly rechargeable aqueous Zn-ion batteries have attracted extensive attention. However, the development of excellent performance cathode is still one of major challenge. Herein, for the first time, we successfully fabricated a free-standing cathode with vertically aligned 1 T phase MoS 2 nanosheet array on carbon cloth and comprehensively investigated its rechargeable aqueous Zn-ion batteries performance. Benefiting from the synergistic effect of vertically aligned 1 T phase MoS 2 nanosheet array and free-standing structure, the free-standing cathode displays a outstanding specific capacity of 198 mA h g−1 at the current density of 100 mA g−1. Impressively, it exhibits distinguished cycling stability, even when cycled at current density of 2000 mA g−1, that the specific capacity retention of 97.2% and 87.8% can be obtained after 1000 and 2000 cycles, respectively. Furthermore, the mechanisms involved were clarfied by combining systematical characterizations and density functional theory calculations. This work will bring new insights for preparing high-performance rechargeable aqueous Zn-ion batteries cathode materials for large-scale energy storage. [ABSTRACT FROM AUTHOR]

Electrochemical impedance spectroscopy (EIS) is one of the most widely used experimental tools in electrochemistry and has applications ranging from energy storage and power generation to medicine. Considering the broad applicability of the EIS technique, it is critical to validate the EIS data against the Hilbert transform (HT) or, equivalently, the Kramers–Kronig relations. These mathematical relations allow one to assess the self-consistency of obtained spectra. However, the use of validation tests is still uncommon. In the present article, we aim at bridging this gap by reformulating the HT under a Bayesian framework. In particular, we developed the Bayesian Hilbert transform (BHT) method that interprets the HT probabilistically. Leveraging the BHT, we proposed several scores that provide quick metrics for the evaluation of the EIS data quality. [ABSTRACT FROM AUTHOR]

Two-dimensional/three-dimensional hierarchical self-supporting potassium ammonium vanadate@MXene hybrid films exhibit excellent electrochemical performance. [Display omitted] Currently, aqueous zinc ion batteries (AZIBs) have grown to be a good choice for large-scale energy storage systems due to their high theoretical specific capacity, low redox potential, low cost, and non-toxicity of the aqueous electrolyte. However, it is still challenging to obtain high specific capacity and stability suitable cathodes. Herein, hierarchical self-supporting potassium ammonium vanadate@MXene (KNVO@MXene) hybrid films were prepared by vacuum filtration method. Due to the three-dimensional nanoflower structure of KNVO with dual ions intercalation, high conductivity of two-dimensional Ti 3 C 2 T x MXene, and the hierarchical self-supporting structure, the AZIB based on the KNVO@MXene hybrid film cathode possessed superior specific capacity (481 mAh/g at 0.3 A/g) and cycling stability (retaining 125 mAh/g after 1000 cycles at a high current density of 10 A/g). In addition, the storage mechanism was revealed by various ex-situ characterizations. Hence, a new viewpoint for the preparation of AZIB self-supporting cathode materials is presented. [ABSTRACT FROM AUTHOR]

Few-layered Ti 3 C 2 T x MXene with abundant −O terminations and low oxidation degree is synthesized through a green etching method at near-ambient temperature. [Display omitted] MXene has drawn considerable attention in energy storage due to particular physicochemical properties. At present, among most near-ambient temperature preparation methods, water is usually served as the main solvent. However, MXene is usually subjected to fast structural degradation on account of water molecules attacking in aqueous solution. Herein, we report a novel water-free etching strategy for synthesizing few-layered Ti 3 C 2 T x MXenes in deep eutectic solvents at near-ambient temperature. Benefitting from the absence of water and macromolecular structure of deep eutectic solvents, the as-synthesized few-layered Ti 3 C 2 T x (DES-Ti 3 C 2 T x) MXene presents abundant −O terminations and low oxidation degree. As a consequence, the DES-Ti 3 C 2 T x MXene displays excellent specific capacitance of 320 F/g at 2 mV/s. Impressively, the DES-Ti 3 C 2 T x MXene exhibits splendid long-term stability that 97% specific capacitance retention can be acquired over 50 000 cycles at high current density of 50 A/g. Therefore, this study offers a new thought for preparing high performance MXene-based materials by water-free etching method. [ABSTRACT FROM AUTHOR]

Hierarchical accordion-like manganese oxide@carbon hybrid with strong interaction heterointerface exhibits outstanding electrochemical performance. [Display omitted] Aqueous zinc ion batteries have attracted extensive concern as a promising candidate for large-scale energy storage because of their high theoretical specific capacity, low cost and inherent safety. However, the lacking of applicable cathode materials with outstanding electrochemical performance have severely hindered the further development of aqueous zinc ion batteries. Herein, we report a hierarchical accordion-like manganese oxide@carbon (MnO@C) hybrid with strong interaction heterointerface and comprehensively inquire into its electrochemical performance as cathode materials for aqueous zinc ion batteries. The unique hierarchical accordion-like layered structure coupling with strong interaction heterointerface between small MnO and carbon matrix efficaciously improve the ion/electron transfer process and enhance structure stability of the MnO@C hybrid. Benefitting from these unique advantages, the MnO@C hybrid bestows excellent specific capacity of 456 mAh g−1 at 50 mA g−1. Impressively, the MnO@C hybrid presents distinguished long-term cycling stability with fairly low decay rates of only 0.0079 % per cycle even over 2000 cycles at 2000 mA g−1. Moreover, comprehensive characterizations are executed to elucidate the mechanism involved. Therefore, this work affords a new idea for developing outstanding performance manganese-based cathode materials for aqueous zinc ion batteries. [ABSTRACT FROM AUTHOR]

The hierarchical 3D a-V 2 O 5 @Ti 3 C 2 T x microsphere with impressive Zn2+ storage ability is prepared by a simple spray drying method. [Display omitted] • The hierarchical 3D a-V 2 O 5 @Ti 3 C 2 T x microsphere was prepared by a simple spray drying method. • The amorphous V 2 O 5 endows abundant active sites for Zn2+ storage and alleviates Ti 3 C 2 T x MXene nanosheets restacking. • The presence of outstanding conductivity MXene framework enhances the conductivity and reaction kinetics. • The 3D a-V 2 O 5 @Ti 3 C 2 T x exhibits ultrahigh reversible capacity, superior rate performance and splendid cycling stability. As candidates of the next generation batteries, aqueous zinc-ion batteries (ZIBs) have drawn widespread attention owing to the advantages of environmental friendliness, low cost and ultrahigh theoretical capacity. In order to obtain superior zinc ions (Zn2+) storage ability, the cathode materials with eminent electrochemical property are placed great expectations. Herein, the hierarchical 3D a-V 2 O 5 @Ti 3 C 2 T x microsphere is prepared by a simple spray drying process. In the heterostructure, the amorphous V 2 O 5 not only endows abundant active sites for Zn2+ storage but also effectively alleviates Ti 3 C 2 T x MXene nanosheets restacking. Meanwhile, the presence of conductive Ti 3 C 2 T x MXene framework significantly enhances the conductivity and reaction kinetics of the electrode material. As a result, the 3D a-V 2 O 5 @Ti 3 C 2 T x exhibits an impressive Zn2+ storage ability, including the high reversible capacity (604 mAh g−1 at 0.5 A g−1), the superior rate performance and the splendid cycling stability. Furthermore, the relevant mechanism is illustrated via various characterizations. Moreover, the as-fabricated pouch ZIBs based on the 3D a-V 2 O 5 @Ti 3 C 2 T x displays a potential practical application prospect as flexible energy storage devices. Hence, this work may provide an inspiration for the rational design of high performance ZIBs cathode materials. [ABSTRACT FROM AUTHOR]

Rechargeable aqueous zinc-ion batteries are emerged as fascinating "beyond Li-ion" battery technologies for large-scale energy storage due to low cost, high theoretical capacity, high safety and environmental friendliness. However, developing cathode materials with outstanding electrochemical performance are prerequisites. Herein, the a-V 2 O 5 @Ti 3 C 2 T x heterostructure is prepared by in situ incorporating amorphous V 2 O 5 with Ti 3 C 2 T x MXene to enhance the rechargeable aqueous Zn-ion batteries performance. Benefitting from the distinctive amorphous structure of a-V 2 O 5 , outstanding conductivity of Ti 3 C 2 T x MXene and the strong synergistic effect between two components, the a-V 2 O 5 @Ti 3 C 2 T x heterostructure presents isotropic ion diffusion paths, plentiful ion storage sites and splendid conductivity. As a consequence, the a-V 2 O 5 @Ti 3 C 2 T x heterostructure displays excellent specific capacity of 544 mAh g−1 at 0.5 A g−1 and outstanding rate performance. Particularly, even at a fairly high current density of 30 A g−1, the a-V 2 O 5 @Ti 3 C 2 T x heterostructure shows an impressive specific capacity of 135 mAh g−1 along with about 100% coulombic efficiency after 1000 cycles. Furthermore, the mechanism related is expounded via comprehensive characterizations. Therefore, this work offers a way for developing high-performance vanadium-based cathode materials for aqueous zinc-ion batteries. [Display omitted] • Amorphous V 2 O 5 @Ti 3 C 2 T x was fabricated via a simple in situ synthetic method. • Synergistic effect amorphous V 2 O 5 and Ti 3 C 2 T x endows fascinating properties. • The cathode presents outstanding specific capacity and cycling stability. • The mechanisms involved were elucidated via comprehensive characterizations. [ABSTRACT FROM AUTHOR]