Silicon\nFew-Layer Graphene Nanocomposite as High-Capacity\nand High-Rate Anode in Lithium-Ion Batteries

Abstract

A silicon-graphene\nheterostructure provides optimal electrochemical\nperformance as anode nanomaterial in both half and full cells with\na commercial NMC111 (LiNi_1/3Mn_1/3Co_1/3O₂) cathode. The anode consists of carbon-coated polycrystalline\nsilicon nanoparticles in between a parallel oriented few-layers graphene\nflakes (FLG). Electrochemical tests in lithium cells display high\ncapacity values (∼2300 mAh/g) with a Coulombic efficiency (CE)\nreaching 99% at current density of 350 mA/g and 1000 mAh/g at current\ndensity values up to 3.5 A/g (CE = 99%). The laminated graphene-based\nstructure yields a protective coating to the silicon nanoparticles\nstill enabling exposure to lithium ions. The method of production\nof the laminated silicon-graphene nanocomposite is scalable and low-cost,\noffering a practical route to the introduction of high silicon content\nanodes in lithium-ion batteries.