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[Display omitted] • A double carbon encapsulated porous composite with compact interface was designed. • The P-Si@rGO@C electrode exhibited inspiring rate-capability and long-cycling life. • The storage mechanism was explored via reaction kinetics, Ex-situ tests, and DFT. • A Li x Si prelithiation suspension was provided to enhance the ICE of the full cell. Developing high-performance composites with fast charging and superior cycle life is paramount for lithium-ion batteries (LIBs). Herein, we synthesized a double-shell carbon-coated porous structure composite with a compact surface (P-Si@rGO@C) using low-cost commercial micron-sized silicon (Si) instead of nanoscale silicon. Results reveal that the unique P-Si@rGO@C features high adaptability to volume expansion, accelerates electron/ion transmission rate, and forms a stable solid electrolyte interphase (SEI) film. This phenomenon arises from the synergistic effect of abundant internal voids and an external double-layer carbon shell with a dense surface. Specifically, the P-Si@rGO@C anode exhibits a high initial coulombic efficiency (ICE) (88.0 %), impressive rate-capability (612.1 mAh/g at 2C), and exceptional long-term cyclability (972.2 mAh/g over 500 cycles at 0.5C). Further kinetic studies elucidate the diffusion-capacitance hybrid energy storage mechanism and reveal an improved Li+ diffusion coefficient (from 3.47 × 10-11 to 2.85 × 10-9 cm2 s-1). Ex-situ characterization confirms the crystal phase change of micron-sized Si and the formation of a stable LiF-rich SEI. Theoretical calculations support these findings by demonstrating an enhancement in the adsorption ability of Si to Li+ (from -0.89 to -0.97 eV) and a reduction in the energy migration barrier (from 0.35 to 0.18 eV). Additionally, practical Li x Si powder is shown to increase the ICE of full cells from 67.4 % to 87.9 %. Furthermore, a pouch cell utilizing the prelithiated P-Si@rGO@C anode paired with LiNi 1/3 Co 1/3 Mn 1/3 O 2 (NCM111) cathode delivers a high initial reversible capacity of 7.2 mAh and 76.8 % capacity retention after 100 cycles. This work provides insights into the application of commercial silicon-aluminum alloy powder in the anode of high-energy LIBs. [ABSTRACT FROM AUTHOR]

The fabricated VS 4 /Ni 3 S 2 /NF NBs was prepared by self-templated strategy, with exposed abundant hetero-interfaces and high active disulfide (S 2 2-) sites. The density functional theory revealed the reversible conversion catalysis mechanism of bridge S 2 2- during HER process, jointly promoting the HER performance. [Display omitted] • A novel VS 4 nanoparticle decorated Ni 3 S 2 nanobelt array was synthesized via one-step organic ligand-assisted solvothermal method. • The abundant disulfide (S 2 2-) moieties grafted on the hetero-interfaces of VS 4 /Ni 3 S 2 led to strong electronic interaction and promote the chemisorption of H-containing intermediates. • The density functional theory reveals the reversible conversion catalysis mechanism about disulfide (S 2 2-) sites during HER process. • The findings provide fresh insights for developing potential polysulfides as high-performance hydrogen-evolving electrocatalysts from water splitting. Elaborate and rational design of cost-effective and high-efficiency non-noble metal electrocatalysts for pushing forward the sustainable hydrogen fuel production is of great significance. Herein, a novel VS 4 nanoparticle decorated Ni 3 S 2 nanobelt array in-situ grown on nickel foam (VS 4 /Ni 3 S 2 /NF NBs) was prepared by a self-templated synthesis strategy. Benefitting from the unique nanobelt array structure, abundant highly active bridge S 2 2- sites and strong electronic interaction between VS 4 and Ni 3 S 2 on the heterointerface, the integrated VS 4 /Ni 3 S 2 /NF NBs exhibited excellent electrocatalytic hydrogen evolution activity and robust stability. The density functional theory (DFT) further revealed the reversible conversion catalysis mechanism of bridging S 2 2- sites in VS 4 /Ni 3 S 2 /NF NBs during HER process. Notably, bidentate bridging S S bonds as the predominant catalytically active centers can spontaneously open once H adsorbed its surface, leading to the aggregation of negative charges on S atoms and thus facilitating the generation of H* intermediates, and spontaneously close when H* desorption is going to form H 2. Our work provides fresh insights for developing potential polysulfides as high-performance hydrogen-evolving electrocatalysts for prospective clean energy production from water splitting. [ABSTRACT FROM AUTHOR]