DataSheet1_Synthesis and Modification of Tetrahedron Li10.35Si1.35P1.65S12via Elemental Doping for All-Solid-State Lithium Batteries.docx

Solid-state electrolyte (SSE), as the core component of solid-state batteries, plays a critical role in the performance of the batteries. Currently, the development of SSE is still hindered by its high price, low ionic conductivity, and poor interface stability. In this work, we report the tailored synthesis of a high ionic conductive and low cost sulfide SSE for all-solid-state lithium batteries. The Li10.35Si1.35P1.65S12 with favorable tetragonal structure was synthesis by increasing the concentration of Si4+, which shows an ionic conductivity of 4.28 × 10−3 S cm−1 and a wide electrochemical stability window of up to 5 V. By further modifying the composition of the electrolyte via ionic doping, the ionic conductivity of Li10.35Si1.35P1.65S12 can be further enhanced. Among them, the 1% Co4+-doped Li10.35Si1.35P1.65S12 shows the highest ionic conductivity of 6.91 × 10−3 S cm−1, 40% higher than the undoped one. This can be attributed to the broadened MS4− tetrahedrons and increased Li+ concentration. As a demonstration, an all-solid-state Li metal battery was assembled using TiS2 as the cathode and 1% Co4+-doped Li10.35Si1.35P1.65S12 as the electrolyte, showing capacity retention of 72% at the 110th cycle. This strategy is simple and can be easily extended for the construction of other high-performance sulfide SSEs.</p

Nitrogen-Doped Carbon Polyhedra Nanopapers: An Advanced Binder-Free Electrode for High-Performance Supercapacitors

Metal–organic framework (MOF)-derived nitrogen-doped porous carbon as electrode material for supercapacitors has recently drawn much attention. However, the development of flexible electrodes composed of MOF-derived carbon is still a great challenge. Herein, nitrogen-doped porous carbon polyhedra (NC) derived from zeolitic imidazolate framework-8 (ZIF8) are assembled into flexible nanopapers assisted with reduced graphene oxide (rGO). The resultant NC/rGO nanopaper shows a hierarchical structure of NC nanoparticle-imbedded rGO framework. A uniform dispersion of NC nanoparticles is achieved due to the rGO framework, and meanwhile, the uniform decoration of NC nanoparticles on rGO nanosheets prevents easy restacking of rGO. A conductive rGO framework further accelerates the electron/ion transportation inside the NC/rGO nanopaper. Furthermore, excellent mechanical performance of rGO framework endows high flexibility to the NC/rGO nanopaper. As a result, the NC/rGO nanopaper as a binder-free electrode delivers high specific capacitance of 280 F g–1 at 1 A g–1, high capacitance retention after 5000 cycles, and high energy density of 19.45 W h kg–1

Cotton Wool Derived Carbon Fiber Aerogel Supported Few-Layered MoSe₂ Nanosheets As Efficient Electrocatalysts for Hydrogen Evolution

Recent studies have proven that newly emerging two-dimensional molybdenum diselenide (MoSe₂) is a promising noble-metal-free electrocatalyst for hydrogen evolution reaction (HER). Increasing the exposures of the active edges of MoSe₂ nanostructures is a key issue to fully realize the excellent electrochemical properties of MoSe₂. In this work, a few-layered MoSe₂/carbon fiber aerogel (CFA) hybrids have been facilely obtained through the combination of high-temperature carbonization and one-pot solvothermal reaction. CFA derived from cotton wool is used as a three-dimensional conductive network for construction of hierarchical MoSe₂/CFA hybrids, where few-layered MoSe₂ nanosheets are uniformly and perpendicularly decorated on the surfaces of CFA. In the designed and prepared hybrids, CFA effectively increases the exposures of the active edges of MoSe₂ nanosheets as well as provides reduced lengths for both electron transportation and ion diffusion. Therefore, the obtained optimal MoSe₂/CFA hybrid exhibits excellent electrochemical activity as HER electrocatalyst with a small onset potential of −0.104 V vs reversible hydrogen electrode and a small Tafel slope of 62 mV per decade, showing its great potential as a next-generation Pt-free electrocatalyst for HER

Molybdenum Carbide Anchored on Graphene Nanoribbons as Highly Efficient All-pH Hydrogen Evolution Reaction Electrocatalyst

The demand for exploiting hydrogen as a new energy source has driven the development of feasible, efficient, and low-cost electrocatalysts for hydrogen evolution reaction (HER) in different reaction media. Herein, we report the synthesis of molybdenum carbide (Mo₂C) nanoparticles anchored on graphene nanoribbons (GNRs) as HER electrocatalyst that can function well under acidic, basic, and neutral conditions. GNRs obtained by unzipping carbon nanotubes (CNTs) display strip-like structure, offering abundant active sites for growing Mo₂C nanoparticles. Furthermore, GNRs could provide a fast electron transport pathway as well as large exposed surface area to allow full impregnation of electrolytes. Coupling with the anticorrosion feature of Mo₂C nanoparticles, the Mo₂C–GNR hybrid exhibits outstanding electrocatalytic performance in all of the acidic, basic, and neutral media, making it promising as a highly efficient electrocatalyst under conditions at all pH values