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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]

[Display omitted] • The industrial solid waste silicon powder is used as low-cost anode material. • Porous composites are constructed by a scalable, facile, and eco-friendly method. • C@void/Si-G anode exhibits excellent reversible capacity and cycling capability. • The synergistic effect of carbon and porous space produces excellent properties. Silicon is a potential anode material for Li battery due to its high theoretical specific capacity (4200 mAh g−1). However, Si is hampered for practical application in Li-battery due to its enormous volume alternation causing instability. Herein, we demonstrated a novel carbon-coated porous structure (C@void/Si-G) synthesized by uniformly wrapping Si into pitch pyrolytic carbon shells and then in-situ removing the sodium chloride template can overcome the bottleneck. It is worth noting that our process for C@void/Si-G also offers a simple route for cost down and mass production of anode material. The C@void/Si-G anodes exhibit an excellent capacity of 1082.7 mAh g−1 at 0.2 C after 200 cycles. Furthermore, it holds a high capacity retention of 81.9 % after 500 cycles at 0.5 C. We found that C@void/Si-G composite only rises about 41% volumetric expansion during 500 operation cycles. This can effectively avoid direct contact between silicon and electrolyte to form a stable solid electrolyte interphase (SEI) film. Especially, practical application of the C@void/Si-G anode is demonstrated in a full cell pairing with LiNi 0.3 Co 0.3 Mn 0.3 O 2 cathode. The full cell presents great cycle retention of 90.1 % at 0.2 C after 100 cycles and a high energy density (446 Wh kg−1). [ABSTRACT FROM AUTHOR]

[Display omitted] • A scalable, facile, and low-cost technology constructed the porous structure. • The influence of copper content on initial coulombic efficiency was explored. • The effect of porosity on the stability of the composite electrode was studied. • Si/Cu/void@C-14 anode exhibited a high rate and long cycle durability. Silicon is an advanced anode material for lithium-ion batteries due to its ultra-high theoretical capacity. However, its commercial application is limited by the enormous volume change and low electrical conductivity. Herein, we synthesize a copper-doped silicon/carbon porous composite that can effectively solve the current dilemma. Uniform anchoring of copper particles on silicon significantly improves the electronic conductivity of composites. By adjusting the content of copper, the initial coulombic efficiency is increased substantially from 60.7 % to 87.6 %. The effect of porosity on the electrochemical properties is systematically studied. The optimized Si/Cu/void@C-14 anode exhibits excellent rate capability (529.3 mAh g−1 at 2 C) and cycle stability (1076.2 mAh g−1 after 300 cycles). The reasons are that the Li+ diffusion coefficient is increased effectively to 3.32 × 10-10-2.54 × 10-9 cm2 s−1, and the volume expansion rate is reduced vastly to 8.8 %. In addition, the full cells coupling LiNi 0.8 Co 0.1 Mn 0.1 O 2 cathode with perlithiated Si/Cu/void@C-14 anode provide a high energy density of 491.5 Wh kg−1 after 100 cycles. It is worth noting that the Si/Cu/void@C-14 composite is synthesized with low-cost raw materials through facile and scalable processes, revealing that the composites have promising potential as high capacity anode materials in a commercial application. [ABSTRACT FROM AUTHOR]