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Solid-state electrolytes (SSEs) are pivotal in the development of high-performance all-solid-state lithium batteries (ASSLBs). Traditionally, halides have been synthesized primarily using solid-state techniques, with wet chemistry synthesis being less frequently utilized. In this work, the cost-effective Fe3+ substituted LaCl 3 -based halide solid-state electrolyte was synthesized via a water-mediated method for the first time. The optimized Li 0.5 Fe 0.25 La 0.58 Cl 3 exhibits an ionic conductivity of 0.741 mS cm-1 at room temperature (RT), accompanied by a low activation energy of 0.26 eV. Additionally, the SSE displays a uniform crystal structure and excellent grain fusion, which is crucial for maintaining intimate solid-solid interfacial contacts within the battery. The ASSLBs based on LiCoO 2 demonstrate good cycling stability. This research contributes novel insights to the expansion of the LaCl 3 -based electrolyte family and diversifies the available synthetic methodologies. • A novel LaCl 3 -based halide was prepared by water‑mediated synthesis first time. • Cost-effective Fe3+ with small ionic radium was selected to substitute the La site. • The 30 %LFLC-WM displays a uniform crystal structure and excellent grain fusion. [ABSTRACT FROM AUTHOR]

Abstract Bimetallic carbides with high activity and stability are promising potential materials for energy-storage application. However, the researches about Fe 2 MoC as electrode material on supercapacitors are comparatively weak, and the processing methods of Fe 2 MoC were also relatively few. Herein, a simple hydrothermal method, combining with carbothermic treatment at 900 °C, is explored to fabricate molybdenum iron carbon (Fe 2 MoC) successfully. Chitosan is not only a carbon source, but also a chelating agent to form bimetallic carbide rather than two separated monometallic carbide during the high-temperature treatment. Fe 2 MoC nanoparticles possessing large specific surface, high activity, stability and small resistance were the promising candidate for electrode material. Systematic electrochemical characterizations have verified the Fe 2 MoC (chitosan as carbon source) possesses a specific capacitance (97.7 F/g at a current density of 0.5 A/g), high rate capability (97.0% capacitance retention from 0.5 to 10 A/g) and cycling stability (83.9% capacitance retention after 1000 cycles) in 1 M KOH. In addition, it offers the energy density of 6.74 Wh/kg at a power density of 21 kW/kg. In view of the low-cost and excellent performance, Fe 2 MoC will hold great promise in energy-storage field for supercapacitors. [ABSTRACT FROM AUTHOR]

Composite polymer electrolytes (CPEs) are gaining increasing interest due to their combined advantages of polymer and inorganic ceramic. "Polymer-in-Ceramic" (PIC) system containing a large portion of ceramic fillers (higher than 50 wt%), possesses superior safety, electrochemical and mechanical properties, which render it a promising strategy for mass production of inorganic ceramic electrolytes. However, the poor organic-inorganic interface compatibility between polymer and ceramic leads to severe agglomeration of ceramic fillers within the polymer electrolyte, resulting in cracks in the membrane that impedes the transportation of lithium ions. Thus, two-dimensional (2D) g-C 3 N 4 nanosheets are introduced into the PIC-type electrolyte as a bridge between the organic and inorganic components to improve the homogeneity of the electrolyte membrane and build an effective transportation network. In this work, a PIC type g-C 3 N 4 / Li 1.3 Al 0.3 Ti 1.7 (PO 4) 3 (LATP)/Poly(vinylidene fluoride) (PVDF) electrolyte membrane with a thickness of 35.2 µm is prepared via a simple solution-casing method and delivers satisfactory all-around properties (a high conductivity of 5.9 × 10−4 S cm−1 at 25 ℃, a high lithium-ion transference number of 0.63 and superior thermal stability). To further evaluate its practicability, a solid-state lithium battery of LiNi 0.8 Mn 0.1 Co 0.1 O 2 |CPEs|Li is assembled and provides good cycling and rate performance at room temperature. This work proves the effectiveness of the 2D g-C 3 N 4 nanosheets in resolving the agglomeration issue and optimizing the electrochemical properties of LATP-based polymer-in-ceramic electrolyte, which provides a universal strategy to modify the PIC-type solid-state electrolytes. [Display omitted] • A flexible PIC-type LATP-based electrolyte modified with 2D g-C 3 N 4 was prepared. • g-C 3 N 4 can reduce the cracks caused by the agglomeration of LATP in a membrane. • An efficient ion transportation network has been constructed in the electrolyte. • The optimal properties of the electrolyte were achieved with 5 wt% g-C 3 N 4. [ABSTRACT FROM AUTHOR]

Bimetallic carbides have aroused wide attention for energy-storage applications recently. In this work, one-dimensional Fe 2 MoC/CNFs (Fe 2 MoC/C nanofibers) are successfully synthesized via a facile electrospinning method for the first time. To obtain the most integrated structure between the Fe 2 MoC nanoparticles and carbon nanofibers, we explore the optimal heating rate during the carbonization treatment. Fe 2 MoC/CNFs exhibits an integrated one-dimensional structure under 800 °C with a heating rate of 5 °C/min. As revealed in the experimental results, Fe 2 MoC/CNFs possesses a high specific surface area of 196.9 m2/g, a high specific capacitance of 347.8 F/g at the current density of 1 A/g, an excellent rate capability of 91% capacitance retention from 1 A/g to 40 A/g, and shows superior cycling stability with the capacitance retention of about 85.6% and Coulombic efficiency of about 100% after 5000 cycles. An asymmetric supercapacitor coin-cell device using Fe 2 MoC/CNFs as the positive electrode displays an energy density of 14.5 Wh/kg at a power density of 300 W/kg and an outstanding cycling life of 93% retention after 5000 cycles. The impressive electrochemical performance indicates that the Fe 2 MoC/CNFs composite is a promising material for efficient supercapacitors. Image 1 • Fe 2 MoC nanofibers can be prepared via a facile electrospinning method. • Fe 2 MoC/CNFs-5 exhibits a superior rate capability and cycle stability. • ASC coin-cell device shows a promising energy and power density. [ABSTRACT FROM AUTHOR]

The nitrogen-doped porous carbon-coated V 2 O 3 (p-NVO@C) prepared by a one-step method exhibits high electron and ion conductivity, and the p-NVO@C exhibits excellent electrochemical performance after electrochemical activation. [Display omitted] • The use of N-containing organic ligands achieve one-step uniform nitrogen doping. • The N doping and carbon coating improve the electrical conductivity of the material. • The N atoms generate a locally enhanced electricfield to accelerate Zn2+ diffusion. • The p-NVO@C cathode demonstrates outstanding specific capacity and cycle stability. The discharge capacity and lifespan of zinc ion batteries currently remain impractical due to limitations in the cathode. Low-valence vanadium oxides are promising cathode material precursors that can be electrochemically converted into highly active hydrated amorphous oxides. However, the activation process itself suffers from structural instability or high local strain, due to the low electronic conductivity and the limited ion diffusion kinetics. To tackle this issue, herein, we synthesize porous carbon-coated nitrogen-doped V 2 O 3 (p-NVO@C) microparticles utilizing a nitrogen-containing vanadium-based metal–organic framework (MOF) as the precursor. The uniform N doping and carbon coating improve the electronic conductivity of the active material particles. The carbon coating also traps the active material to reduce its dissolution loss; the high porosity of the p-NVO@C alleviates the stress from Zn2+-intercalation-induced expansion and shortens the ion transport paths. Moreover, first-principles calculations indicate that the doped N atoms in vanadium oxides generate a locally enhanced electric field, which accelerates the diffusion of Zn2+. Given the above advantages, the p-NVO@C particles demonstrate an outstanding specific capacity of 501 mAh/g at a current density of 0.2 A/g and a remarkable rate performance after the initial activation. The capacity retention rate remains as high as 95.7 % after 2000 cycles at a current density of 10 A/g. Ex-situ characterizations confirm the robust structural stability during phase transition cycles. This work provides an excellent solution to developing cathode materials for high-performance aqueous zinc ion batteries. [ABSTRACT FROM AUTHOR]

Core-shell hierarchical structured composites have demonstrated great advantages in numerous energy storage devices. In particular, structured composites with rationally structural components and controllable morphology are the most effective in enhancing electrochemical properties. In this work, MnO 2 @NiCo 2 O 4 @Ti 3 SiC 2 /CC (carbon cloth) core-shell hierarchical structured composites were designed and successfully synthesized via electrospinning followed by a two-step hydrothermal reaction. The Ti 3 SiC 2 /CC nanofibers and core-shell nanoarrays were able to improve the specific capacitance and cycling stability. In the three-electrode system, the specific capacitance of MnO 2 @NiCo 2 O 4 @Ti 3 SiC 2 /CC was observed as 1938.2 F/g at a current density of 1 A/g, while the rate capability retention was observed as 81.7% between 1 and 10 A/g. Furthermore, a superior cycling stability was observed following 5000 cycles with a specific capacitance retention rate of 55.4%. Employing MnO 2 @NiCo 2 O 4 @Ti 3 SiC 2 /CC as the all solid-state supercapacitor positive electrode exhibited a high energy density of 58.0 W h/kg at the power density of 800 W/kg. Results demonstrate the potential of the MnO 2 @NiCo 2 O 4 @Ti 3 SiC 2 /CC as an electrode material with phenomenal electrochemical properties for supercapacitors. [ABSTRACT FROM AUTHOR]

Abstract NiFe 2 O 4 (NFO) with different morphologies were successfully synthesized via a facile hydrothermal method of different precipitants. Results showed that the NFO obtained using urea as precipitant (NFO-U) formed a nanosheet shape, while the powders prepared using CH 3 COONa (NFO-C) exhibited a nanoparticle structure. Both of the two NFO showed a good crystallinity. Conclusion was reached through the results of BET and electrochemical tests that layer structure would improve the properties through a larger specific surface area. Encouragingly, the specific capacitance of NFO-U could arrive 240.9 F/g at the current density of 1 A/g. It was worth noting that the cycle performance of NFO-U was excellent, of which the specific capacitance improved to 128% after 2000 cycles. In addition, an asymmetric supercapacitor (ASC) system was constructed utilizing NFO-U as positive electrode while activated carbon (AC) as negative electrode. The two-electrode system showed a good performance with energy density of 10.15 Wh/kg at a power density of 140 W/kg. Therefore, the construction of sheet-like structures greatly improved the electrochemical performance of NiFe 2 O 4 materials. [ABSTRACT FROM AUTHOR]

Morphology of transition metal oxide largely affects its electrochemical energy storage properties. This also applies to its composites. In this paper, NiFe 2 O 4 /Graphene nanosheets composites (NFO/GNSs) are successfully prepared by a facile hydrothermal method. NiFe 2 O 4 (NFO) in the sample exhibits a unique nanosheet morphology, vertically arranging on the graphene nanosheets (GNSs). Microscopically, NFO nanosheets interpenetrate on the surface of graphene to form a continuous network structure. The sample exhibits excellent specific capacitance and rate performance. It is worth mentioning that the specific capacitance increases to 140% after 5000 cycles, showing superior cycle stability. This may be due to the conductive network formed by NFO nanosheets and GNSs. Excellent electrochemical performance indicates excellent application prospects of materials in supercapacitor electrodes. Image 1 • Unique NiFe 2 O 4 nanosheets structure with graphene nanosheets was successfully prepared by a hydrothermal method. • NiFe 2 O 4 nanosheets/graphene performed a better specific capacitance, arriving at 464.15 F/g at current density of 1 A/g. • The network structure formed between NiFe 2 O 4 nanosheets and graphene nanosheets provides excellent cycle performance. [ABSTRACT FROM AUTHOR]