Search

[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 3-dimensional structure comprised of silicon nanoparticles assembled on an nitrogen-doped carbon foam with MXene as the cover layer (MXene@SiNPs@NC foam) is demonstrated. • The MXene layer protects the silicon nanoparticles from directly contacting the electrolyte. • The nitrogen-doped carbon foam and MXene are used as the conductive frame and covering layer, providing effective channels for electron transport/ion diffusion. • The substantial void spaces between the MXene layer and the nitrogen-doped carbon foam skeleton can accommodate the significant silicon nanoparticles volume change during lithiation/delithiation. • The self-standing and binder-free anode was used without a metal current collector. Silicon (Si) is one of the most promising anode materials for lithium-ion batteries (LIBs) because of its high specific capacity. However, the poor cycling stability results from huge volume fluctuation and low intrinsic conductivity, which greatly hinders Si-based anodes development. Herein, we construct a three-dimensional structure comprised of Silicon nanoparticles (SiNPs) anchored on a nitrogen -doped carbon (NC) foam with a covered MXene layer (MXene@SiNPs@NC foam), which acts as a self-standing Si-based anode for high performance LIBs. The design of NC foam as the conductive frame and MXene as the covering layer provides effective channels for electron transport/ion diffusion, and simultaneously allows the anode to adapt to the drastic Si volume change during lithiation/delithiation. The self-standing MXene@SiNPs@NC foam electrode delivers a high specific capacity (1658 mAh g−1 after 100 cycles at 0.1C) and a steady cycling capacity (857 mAh g−1 after 500 cycles at 0.5C). Moreover, a full-cell constructed using MXene@SiNPs@NC foam //NCM 111 exhibits a high gravimetric energy density (433 Wh kg−1). This MXene@SiNPs@NC foam anode with good electrochemical performance renders as a promising candidate for broad LIBs applications. [ABSTRACT FROM AUTHOR]