Vertical Graphene Growth on SiO Microparticles for Stable Lithium Ion Battery Anodes

Silicon-based materials are considered as strong candidates to next-generation lithium Ion battery anodes because of their-ultrahigh specific capacities. However, the pulverization and delamination of electrochemical active materials originated frOrn the huge volunie, expansion (>300%) of silicon during the lithiation procOSS results in rapid capacity fade, especially in high Mass loading electrodes. Here we demonstrate that direct cheridical vapor deposition (CVD) growth Of vertical graphene nanosheets on commercial SiO microparticles can.provide a stable conducting network via interconnected verticalgraphene encapsulation during lithiation, thus remarkably improving the cycling stability in high mass loading SiO anodes. The vertical grapherie encapkulated SiO (d-SiO@vG) anode exhibits a'high capacity of 1600 mA. big and a retention up to 93% after IOG cycles at a high areal mass loadig of 1.5 nig/cm(2). Furthermore, 5 wt % d-SiO@vG as additives increased the energy density of traditiOnal graphite/NCA 18650 cell by,-15%. We believe' hat the results strongly imply the important role of CVD-grown vertical graphene encapsulation in promoting the, commercial application of silicon-based anodes.