Graphene Oxide-Wrapped Porous Hollow Co₃O₄ Microspheres with Enhanced Lithium Storage Performance

Abstract

Porous hollow Co3O4 microspheres wrapped with graphene oxide were synthesized by a step solvothermal method and subsequent heat treatment. Benefiting from the design of special porous hollow microspheres, the effective specific surface area was greatly increased, the sufficient contact between the porous hollow Co3O4 microspheres and electrolyte was achieved, and then a charge specific capacity of 888.59 mA h g–1 was gained. Meanwhile, partial stress from the charging/discharging process was greatly relieved due to the abundant pores and hollow structure, excellent cycling stability was realized, and the charge specific capacity of the 1000th cycle was 465.75 mA h g–1 at 5 C (1 C = 890 mA g–1). In addition, the conductivity of Co3O4 microspheres was effectively improved due to the tight package of graphene oxide to Co3O4 microspheres, and superior rate performance was attained (280.99 mA h g–1 at 10 C).