Scalable Fabrication of Silicon‐Graphite Microsphere by Mechanical Processing for Lithium‐Ion Battery Anode with Large Capacity and High Cycling Stability

Abstract

In order to combine the high stability of graphite and the large theoretical capacity of silicon, silicon-graphite composites attract tremendous attentions. However, the cycling stability is still a bottleneck hindering their commercialization due to the large volume expansion and poor interface compatibility. In this study, the bead grinding method is used to break micro-sized silicon and graphite particles by strong shear force simultaneously, inducing the solid-solid interface reaction between fresh silicon nanoparticles and graphite nanosheets. Subsequently, an evaporation induced self-assembly happens in spray drying process, allow for scalable synthesis of Si-graphite microsphere. The silicon-graphite microsphere (SiÀ G microsphere) delivers an excellent cycling performance, with a reversible capacity of 1895 mAh g À 1 at a current density of 0.5 A g À 1 over 500 cycles and a capacity retention of 99.8 %. Moreover, the pouch-type full battery of SiÀ G microsphere/ graphite j j LiNi 0.5 Co 0.2 Mn 0.3 O 2 exhibits remarkable cycling stability with the capacity retention of 79.3 % after 800 cycles. The manufacture process using commercial raw materials and simple mechanical strategy demonstrates great potential for the low-cost and scaled synthesis of high-performance silicongraphite anodes.

Easy Diameter Tuning of Silicon Nanowires with Low-Cost SnO2-Catalyzed Growth for Lithium-Ion Batteries

“…This allows for choosing a trade-off between high first Coulombic efficiency (favored by large sizes) and high stability in long-term cycling (favored by small sizes). Our best SiGt composite, grown from SnO 2 catalysts with an average SiNW diameter of 37 nm and a high silicon content of 30% wt., attained a remarkable initial Coulombic efficiency of 82%, among the highest in the recent literature [ 46 , 47 , 48 , 49 ]. Further work is ongoing to control the chemical composition of the composite at the interface with the electrolyte, in particular, at the silicon surface, to reduce its reactivity and the extent of SEI formation.…”

Interphasial Pre‐lithiation and Reinforcement of Micro‐Si Anode through Fluorine‐free Electrolytes

“…Inset: the enlarged part of curves at the very beginning of lithiation. (b) The comparison of ICE and capacity between our work and previous reports, including porous μ‐Si, [19–27] μ‐Si/C (metal) composites, [28–33] μ‐Si anodes with novel binders, [34–43] μ‐Si with coating layers [44] and electrolytes modification for μ‐Si anodes [11,45–46] . (c) The rate performance of different electrolytes and (d) corresponding charge–discharge curves in LBH electrolytes at various rates.…”

Rethinking the Electrode Multiscale Microstructures: A Review on Structuring Strategies toward Battery Manufacturing Genome

“…This wrapping process and structure resembled the "collage" technique in art. For the resulting thick electrodes as shown in Figure 4c, the graphene-coated cathode with a mass loading of >20 mg cm −2 presented much higher volumetric capacities [36] Copyright 2022, Wiley-VCH. Structure of the sulfur/carbon black composite particles by d) synchrotron measurement of a packed bed of the particles and e) FIB preparation of one composite particle.…”

“…Shen at al. [ 36 ] reported the scalable fabrication of spherical Si/graphite composites by using bead grinding as shown in Figure 3 a. The bead grinding broke the commercial microscale Si or graphite to nanoscale particles or sheets, respectively.…”

“…Reproduced with permission. [ 36 ] Copyright 2022, Wiley‐VCH. Structure of the sulfur/carbon black composite particles by d) synchrotron measurement of a packed bed of the particles and e) FIB preparation of one composite particle.…”