High-performance anodes of Si@B-C/rGO nanoparticles for liquid and all-solid-state lithium-ion batteries

Silicon is regarded as one of the most prospective anode candidates for the new generation of lithium ion batteries, because of its high theoretical specific capacity. Nevertheless, the huge expansion/contraction of silicon during cycling leads to rapid capacity decay. Herein, to suppress the concomitant mechanical damage, a composite material Si@B-C/rGO is prepared by in-situ encapsulating Si particles inside boron-doped carbon skeleton (B-C) and then loaded on reduced graphene oxide (rGO). The specific capacity of Si@B-C/rGO materials maintain at 1600 and 956 mAh g−1 after 100 cycles in liquid-phase and all-solid-state batteries, respectively. The performance improvement could be ascribed to main factors below: (i) The carbon shell significantly relieves expansion/contraction of silicon nanoparticles; (ii) The boron doping is conducive to the insertion/extraction of lithium-ions, because boron atoms have stronger affinity to lithium-ions than carbon; (iii) Loading Si@B-C nanoparticles on rGO can reduce particle agglomeration, and rGO provides a conductive network that ensures the transmission of lithium-ions. This work gives valuable reference to the design of advanced silicon-based anode materials to develop liquid and all-solid-state lithium-ion batteries.