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]

Currently, with the rise of the photovoltaic industry, how to effectively treat waste silicon powder from an environmentally friendly and economic point of view becomes significant. We reported a simple method to prepare the "core-shell" structure of silicon/carbon nanotubes/carbon (Si/CNTs/C) composite by ball-milling using waste silicon powder. Specifically, The synergistic effect of CNTs and amorphous carbon matrix is beneficial to improving the transmission rate of Li-ions and electrons, and facilitating the reaction kinetics of Li-ions in the process of lithiation/de-lithiation. Meanwhile, the carbon coating layer reduces the direct contact between silicon and the electrolyte, which greatly alleviates the volume expansion of silicon in cycling. With these merits, Si/CNTs/C anode shows high rate performance and outstanding cycling stability up to 300 cycles at 0.2C. Furthermore, full cells assembled with pre-lithiated Si/CNTs/C anodes and commercial NCM811 cathodes deliver considerable initial coulombic efficiency (84.4%) and high energy density (502 Wh kg−1). Si/CNTs/C composites prepared by ball-milling show excellent long-cycle stability and rate performance. [Display omitted] • Industrial waste silicon is used to prepare silicon-based anodes. • Two-step ball milling method to prepare Si/CNTs/C composite. • A solution-based chemical prelithiation method is proposed. • Si/CNTs/C anode exhibits excellent long-cycle stability and good rate performance. • A full cell shows an improved ICE (84.4%) and a higher energy density (502 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]

• An N-doped CNT-interspersed hierarchical carbon shell structure by Co-Zn bimetallic ZIFs-triggered surface polymerization of dopamine has been designed and successfully prepared for stabilized silicon anode (PDA@CoZn-NC@Si). • PDA@CoZn-NC@Si electrodes deliver better cycle stability of 814 mAh/g at 0.5C with a capacity loss of −0.14% per cycle over 400 cycles and possess excellent rate capability. • The solution-based chemical prelithiation method is used to compensate for irreversible loss of anode capacity, and the full cell exhibits an improved ICE (88.3%) and a higher energy density (419.8 Wh kg−1). The application of silicon-based anode remains a serious challenge due to its intrinsic volumetric expansion effect and low conductivity. In our work, a novel CNT-interspersed hierarchical carbon shell structure (denoted as PDA@CoZn-NC@Si) is synthesized by wrapping Si uniformly in the bimetallic zeolite imidazolate frameworks (ZIFs) and then encapsulated with a dopamine-derived carbon shell. The PDA@CoZn-NC@Si anode delivers better cycle stability of 814 mAh/g at 0.5C for 400 cycles (only −0.14% capacity reduction per cycle) and possesses excellent rate capability, which benefits from the inner porous buffer spaces, interspersed CNT, and solid heterogeneous carbon shells. In addition, the full cell is assembled by pairing a solution-based chemically prelithiated PDA@CoZn-NC@Si anode with a Li(Ni 1/3 Co 1/3 Mn 1/3)O 2 (NCM111) cathode, and it presents an improved initial coulombic efficiency (88.3%) and a high energy density (419.8 Wh/kg). This study provides effective guidance for optimizing the microstructure design and prelithium of Si-based anodes. [ABSTRACT FROM AUTHOR]