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Lithium‐sulfur batteries (LSBs) are among the most encouraging competitors for the next‐generation energy storage system, nevertheless, the shuttle effect resulted from the soluble lithium polysulfides (LiPSs) and slow chemical kinetics hinder the pragmatic application of LSBs. To address those issues, herein, a uniform three‐dimensional (3D) structure constructing carbon nanofibers (CNF) with polar Mo2C nanoparticles (Mo2C@CNF) was designed and coated onto one side of pristine conventional polypropylene separator (Mo2C@CNF/PP). The Mo2C@CNF with high electrical conductivity not only chemically constrained the LiPSs by chemical trapping, but also catalyzed the conversion of LiPSs to Li2S2/Li2S. Cells with Mo2C@CNF/PP separator presented a high specific capacity of 732.9 mAh g−1; 500 mAh g−1 was kept, due to sluggish capacity decay (0.063 % per cycle), after 500 cycles. Judging from the outstanding electrochemical performance of batteries with the Mo2C@CNF/PP separator, the proposal is an enlightening strategy for the advancement high‐performance LSBs. [ABSTRACT FROM AUTHOR]

Ba0.85Ca0.15Zr0.9Ti0.1O3 (BCZT) ceramics with various grain sizes were fabricated through solid-state method followed by different sintering temperatures. The influences of grain size and phase structure on the electric properties and energy storage performance were systematically investigated. The remnant polarization and quasi-static piezoelectric constant of BCZT samples increase gradually as grain size increases, and the samples with the grain size of 44.37 µm exhibit excellent ferroelectricity and piezoelectricity (2Pr = 25.4 µC/cm2, d33 = 513 pC/N). Although the energy storage density of BCZT samples with the grain size of 8.28–44.37 µm is relative lower, all the ceramic samples have higher energy storage efficiency (82–87.4%). There is the maximum energy storage density in phase transition temperature of tetragonal–cubic phase for all BCZT ceramics and the maximum energy storage density first increases and then decreases with the increase of grain size. But the energy storage density of BCZT ceramics near room temperature decreases with increasing of grain size. The smaller grain size is beneficial to improve the room temperature energy storage density of BCZT samples and is disadvantageous to obtaining superior ferroelectric and piezoelectric properties. [ABSTRACT FROM AUTHOR]

[Display omitted] • Tix+ in-situ intercalation strategy via titanium foil/vanadium ion solution interface for long cycle LSB. • Inserted Tix+ can strengthen interlayer interaction so as to enhance lithium-ion mobility rate. • Mixed valence of V5+/V4+ reduces the stress and strain of lithium-ion intercalation. • Ti-VO 2.375 /S cathode delivers lower capacity decay with a stable coulombic efficiency. Lithium sulfur battery (LSB) has great potential as a promising next-generation energy storage system owing to ultra-high theoretical specific capacity and energy density. However, the polysulfide shuttle effect and slow redox kinetics are recognized the most stumbling blocks on the way of commercializing LSB. On this account, for the first time, we use Tix+ in-situ intercalation strategy via titanium foil/vanadium ion (V5+) solution interface to modify the layer of vanadium oxide for long cycle LSB. The inserted Tix+ strengthens interlayer interaction and enhances lithium-ion mobility rate. Meanwhile, based on density functional theory (DFT) calculation, the mixed valence of V5+/V4+ in the vanadium oxide structure reduces the stress and strain of lithium-ion intercalation through the interlayer support of titanium ions (Tix+). Also, Tix+ refines the structural stability of the sulfur wrapped composite matrix so as to facilitate the LiPSs transformation, and improve the electrochemical performances. Consequently, the Ti-VO 2.375 /S cathode delivers a lower capacity decay of 0.037 % per cycle over 1500 cycles with a stable coulombic efficiency around 100 %. [ABSTRACT FROM AUTHOR]

(0.9 – x)BaTiO3–0.1BiYbO3–xBiAlO3 (x = 0, 0.02, 0.04, and 0.08) lead‐free ferroelectric ceramics are synthesized using conventional sintering (CS) and microwave sintering (MWS) methods. The microstructure, dielectric and ferroelectric properties, relaxation behavior, and energy storage properties are investigated systematically. X‐ray diffraction (XRD) patterns show a single perovskite phase for all samples. Scanning electron microscope (SEM) images indicate that MWS method can impede the grain growth, whereas the introduction of BiAlO3 can lead to the increase in the grain size. Dielectric measurements reveal that an obvious dielectric relaxation behavior can be strengthened by MWS, and the improvement of the dielectric constant (εr) of ceramics is realized by MWS. Incorporated with BiAlO3 contributes to enhancement of the frequency and temperature stabilities of the dielectric constant for BaTiO3–BiYbO3 ceramics. The slim hysteresis loops are observed, and the maximum polarization of the sample sintered by MWS is higher than that sintered by CS. The MWS samples possess a higher energy density which is about 2 times larger than that of CS samples, and the largest energy storage density ≈0.86 J cm−3 and energy storage efficiency ≈97.44% are, respectively, obtained at x = 0 and 0.04 for MWS ceramics. [ABSTRACT FROM AUTHOR]

(1 − x)BaTiO3–xBiAlO3 relaxor ferroelectric ceramics were prepared by the conventional sintering (CS) and the microwave sintering (MWS) methods, respectively. The microstructure, the dielectric properties, the relaxation characteristic, the ferroelectric and the energy storage properties were investigated in detail. The results show that a single perovskite phase exists in ceramic samples sintered by CS and MWS. The addition of BiAlO3 into BaTiO3 and the MWS method result in the reduction of the grain size and the porosity of BaTiO3 ceramic. This leads to the enhanced diffuse transition and frequency dispersion. The dielectric constant and loss decrease with increasing the BiAlO3 content, and the temperature and the frequency stabilities are enhanced by introducing BiAlO3 into BaTiO3. The remnant polarization (Pr) increases initially and then decreases with the increase of BiAlO3 content, the maximum values of Pr (9.5 μC/cm2 for CS and 7.27 μC/cm2 for MWS) are obtained at x = 0.02. The addition of BiAlO3 can elevate the variation of polarization ΔP (Pmax − Pr), its maximum values (12.56 μC/cm2 for CS ceramic and 12.2 μC/cm2 for MWS ceramic) are acquired at x = 0.04, 0.08, respectively. The energy storage properties indicate that the energy storage density (Wrec) increases, while the energy storage efficiency (η) firstly decreases and then increases with the increase of x. [ABSTRACT FROM AUTHOR]

Carbon materials have attracted significant attention as anode materials for sodium ion batteries (SIBs). Developing a carbon anode with long‐term cycling stability under ultrahigh rate is essential for practical application of SIBs in energy storage systems. Herein, sulfur and nitrogen codoped mesoporous hollow carbon spheres are developed, exhibiting high rate performance of 144 mA h g−1 at 20 A g−1, and excellent cycling durability under ultrahigh current density. Interestingly, during 7000 cycles at a current density of 20 A g−1, the capacity of the electrode gradually increases to 180 mA h g−1. The mechanisms for the superior electrochemical performance and capacity improvement of the cells are studied by electrochemical tests, ex situ transmission electron microscopy, X‐ray diffraction, X‐ray photoelectron spectroscopy, and Raman analysis of fresh and cycled electrodes. The unique and robust structure of the material can enhance transport kinetics of electrons and sodium ions, and maintain fast sodium storage from the capacitive process under high rate. The self‐rearrangement of the carbon structure, induced by continuous discharge and charge, lead to the capacity improvement with cycles. These results demonstrate a new avenue to design advanced anode materials for SIBs. [ABSTRACT FROM AUTHOR]

• The obstacles of lithium sulfur batteries (LSBs) and the important role of catalysts were introduced. • The research progress of phosphides doped with different cations in LSBs was elaborated. • The current synthesis methods of metal phosphides were summarized. • The applications of different metal phosphides were comprehensively introduced in the design of cathode sulfur carrier materials, modification of separator, and Li anode protection. • The challenges of using metal phosphide catalysts in commercial LSBs and design strategies to promote their commercialization were proposed. Lithium-sulfur batteries (LSBs) are widely acknowledged as the most promising energy storage systems for the future, primarily due to their remarkably high theoretical energy density. Nonetheless, the advancement of LSBs encounters various hurdles, including the substantial expansion of the cathode material, inadequate conductivity of the active material S and discharge product Li 2 S, the evident shuttle effect of lithium polysulfide (LiPS), and the sluggish sulfur conversion kinetics. These challenges become particularly evident when handling high sulfur loading. The issue of uneven Li dendrite growth at the anode significantly affects the long-term functionality and safety of batteries. Consequently, there is a pressing requirement for battery designs that effectively tackle these challenges. Metal phosphide, owing to its remarkable catalytic activity and distinctive physicochemical properties, has been extensively investigated and is anticipated to serve as a bifunctional material in LSBs systems. By manipulating the composition of cations, it is possible to obtain monometallic phosphide, bimetallic phosphide, and trimetallic phosphide through tailored design approaches. It has been found that metal phosphide catalysts can effectively adsorb soluble LiPS and catalyze its rapid conversion. Moreover, the synthesis of composite materials by incorporating metal phosphides with other compounds results in a synergistic effect that significantly improves catalytic performance. This study offers a thorough overview of the diverse applications of metal phosphides in enhancing cathode sulfur support materials, modifying separators, and protecting lithium anodes. The significance of metal phosphides in facilitating the anchoring of lithium polysulfides, improving electrochemical reaction rates, facilitating the nucleation and dissolution of lithium sulfide, enhancing electron and ion transport, and promoting uniform lithium deposition was underscored. Additionally, the obstacles and potential opportunities for metal phosphides in future lithium-sulfur batteries are examined, along with their practical utility. [ABSTRACT FROM AUTHOR]

Nowaday, developing sustainable energy storage and conversion techniques is of great desire to alleviate energy demands and environmental pollution, in which the core issue is to develop cost-efficient, high-performance and sustained electrode materials. Herein, we proposed a cost-efficient strategy by integrating solvothermal technique, calcination and up-stream gas method to fabricate bifunctional phosphorus-doped CoO core@shell microspheres, which perform great in both energy conversion (hydrogen evolution reaction) and energy storage (supercapacitor). Due to core@shell structure and phosphorus doping, the resulted P–CoO core@shell structures possess high specific surface area, enhanced conductivity and additional active sites. As a result, the P–CoO exhibits excellent electrocatalytic HER performances in alkaline media with a low overpotential (143 mV at 10 mA/cm2) and long-term stability (more than 24 h). Meanwhile, the prepared material presents greatly improved supercapacitive properties with ultrahigh capacitance (1845 F/g at 1 A/g) and excellent cycling stability. Therefore, this strategy provides a new contribution to develop multifunctional electrochemical-active materials for energy conversion and storage. • An economical route was proposed to fabricate bifunctional P–CoO core@shell spheres. • The route combines solvothermal technique, calcination and upstream gas method. • P–CoO delivers low overpotential of 143 mV and long stability as HER electrocatalyst. • P–CoO presents high capacitance and good cycling stability as capacitive material. • P-doping on core@shell structure is the key for the performance enhancement. [ABSTRACT FROM AUTHOR]

Solid oxide electrolysis cell (SOEC) has great application prospects in the fields of renewable energy storage, CO 2 capture and utilization. One of the key factors hindering the development of SOEC is the lack of suitable cathode materials. In this study, we designed and developed a kind of new micro-nano heterostructure materials Co@Sr 1.95 Fe 1.4 Co 0.1 Mo 0.4 Ti 0.1 O 6-δ (Co@SFCMT), Co nanoparticles uniformly distributed on the SFCMT matrix and provided rich electric catalytic active sites, SFCMT showed excellent oxygen ion transport performance. The synergistic effect of Co nanoparticles and Sr 1.95 Fe 1.4 Co 0.1 Mo 0.4 Ti 0.1 O 6-δ (SFCMT) increased the rate of CO 2 reduction reaction (CO 2 RR). At 1.8 V and 800 °C, the maximum electrolytic current density of the cell with Co@SFCMT as the cathode reached 2.57 A cm−2. In addition, Co@SFCMT showed good stability at 1.5 V and 750 °C, with no performance decay even after 200 h of continuous operation. The micro-nano heterostructure design strategy of perovskite oxides will not only open new avenues for designing SOEC electrodes, but also be expected to promote the development of other energy storage and conversion systems. • A novel heterostructure cathode material for solid oxide electrolysis cell was prepared. • The Co@Sr 1.95 Fe 1.4 Co 0.1 Mo 0.4 Ti 0.1 O 6-δ material exhibited high activity and stability. • Structural stability of the material was regulated by introducing Ti. • No performance decay was observed after 200 h of operation. [ABSTRACT FROM AUTHOR]

• CNT@Co 3 O 4-x -P with dual defects of O-vacancy and P-doping is developed. • The construction of O-vacancy mainly promotes polysulfide conversion kinetics. • The phosphorus doped atoms mainly contribute to polysulfide adsorption. • CNT@Co 3 O 4-x -P/S based cell shows excellent specific capacity and cycling stability. Lithium-sulfur (Li-S) battery is considered as a burgeoning energy storage device owing to its high theoretical energy density. However, the shuttle effect and sluggish kinetics of sulfur species during conversion reactions lead to the challenges in attaining commercial application of high-performance Li-S battery. Herein, a double-defect engineering strategy is developed to endow CNT@Co 3 O 4 with favorable effects on Li-S chemistry by introducing oxygen vacancies and phosphorus doped atoms (CNT@Co 3 O 4-x -P). Experimental and theoretical investigations indicate that both enhanced adsorption and conversion of polysulfides can be realized on the surface of CNT@Co 3 O 4-x -P. Taking advantage of the superb adsorption-conversion property of CNT@Co 3 O 4-x -P, the cell achieves a specific capacity of 903 mAh/g with splendid cyclability at 2 C and a high areal capacity of 7.3 mAh cm−2 under the lean electrolyte (E/S = 6 μL E mg−1 S) condition. This work offers a creative approach to implement high-performance Li-S batteries and promotes the application of Li-S batteries. [ABSTRACT FROM AUTHOR]

• (PLZT@SiO 2) core-shell structure ceramic materials are synthesized by the sol-gel combination with the solid-phase method. • Its dielectric constant can be adjusted by holding time. • The surface of PLZT coated with SiO 2 can increase the breakdown electric field (BDS) and thus increase the energy density. Antiferroelectric materials are considered promising energy storage materials because they have excellent energy density during the antiferroelectric phase transition. Herein, Pb 0.925 La 0.05 Zr 0.95 Ti 0.05 O 3 @SiO 2 (PLZT@SiO 2) core-shell structure ceramic materials were synthesized by combing sol-gel method with conventional solid-phase method. The effect of holding time (3 h, 6 h, 9 h, 12 h) on the electrical properties and energy storage properties of PLZT@SiO 2 ceramics were investigated. TEM results indicate the formation of a core-shell structure. Transmission electron microscope (TEM) reveals the formation of core-shell structure. X-ray diffraction (XRD) obtained clear tetragonal perovskite structure PLZT and SiO 2 phase. The phase transition temperature of PLZT@SiO 2 ceramics is between 222 °C and 225 °C, and its dielectric constant can be adjusted by the holding time. The PLZT with surface coated SiO 2 can increase the breakdown electric field (BDS) and thus increase the energy density. When the holding time is 9 h, the breakdown electric field is as high as 156.84 kV/cm, and the recoverable energy density (W re) is 1.92 J/cm3, which is mainly determined by its high density and breakdown electric field. [ABSTRACT FROM AUTHOR]

• The PLZT@SiO 2 composite ceramic was prepared by the Stöber method, which increased the density of the ceramic, and greatly improved the energy storage density. • SEM results indicate that SiO2 weakens the crystallinity of the ceramics and restricts the grain growth of all the specimens. • Compared with the single-phase PLZT ceramics, although the electric breakdown field strength of the core-shell structure sample has not improved much, its energy storage density has increased significantly. Pb 0.925 La 0.05 Zr 0.95 Ti 0.05 @ x wt%SiO 2 (PLZT@ x wt%SiO 2 , x = 0, 1, 2, 3 and 4, marked as S0, S1, S2, S3, S4 respectively) ceramics were prepared by combining conventional sol-gel method with Stöber method, the microstructure, electrical properties and energy storage characteristics were comparatively investigated. TEM analysis prove that samples S1, S2 and S3 present core-shell structures. SEM results indicate that SiO 2 weakens the crystallinity of the ceramics and restricts the grain growth of all the specimens. When the concentration of SiO 2 is 3 wt%, the sample shows better energy storage characteristics, the value of W re of this sample can reach 2.29 J/cm3; In addition, temperature (T) will induce a phase change in the sample. When T < 50 ℃, sample S3 is ferroelectric phase, when T is in the range of 50–130 ℃, sample S3 is coexistence of anti-ferroelectric and ferroelectric phase, showing double electric hysteresis loops. In this temperature range, the temperature stability of sample S3 is the poorest, and the increases in W re density and η are 317.39 % and 25.04%, respectively. The core-shell structure samples prepared by the Stöber method can increase the energy storage density by reducing the turnover electric field. The energy storage density has increased from 0.3 J/cm3 to 2.29 J/cm3. [ABSTRACT FROM AUTHOR]