Graphene Aerogels with Anchored Sub-Micrometer Mulberry-Like ZnO Particles for High-Rate and Long-Cycle Anode Materials in Lithium Ion Batteries

摘要

Graphene aerogels (GAs) anchoring hierarchical, mulberry-like ZnO particles are fabricated in situ using a one-step solvothermal reaction. The resulting composites can function as anodes in lithium ion batteries, where they exhibit a high capacity and cyclic stability. The reversible capacities obtained are 365, 320, and 230 mA h g(-1) at current densities of 1, 2, and 10 A g(-1). Their high reversible capacity is 445 mA h g(-1) at a current density of 1.6 A g(-1); this value is maintained even after the 500th cycle, The excellent electrochemical performance is attributed to strong oxygen bridges between ZnO and graphene, where C-O-Zn linkages provide a good pathway for electron transport during charge/discharge cycles. Additionally, the hierarchical structure of the ZnO microballs suppresses stacking among the graphene layers, allowing the GAs to accelerate the transport of lithium ions. Furthermore, the GA framework enhances the electrical conductivity and buffer any volume expansion.