Free-standing and binder-free lithium-ion electrodes based on robust layered assembly of graphene and Co3O4 nanosheets

Abstract

Free-standing and binder-free Co₃O₄/graphene films were fabricated through vacuum filtration and thermal treatment processes, in which sheet-like Co₃O₄ and graphene were assembled into a robust lamellar hierarchical structure via electrostatic interactions. The morphological compatibility coupled with strong interfacial interactions between Co₃O₄ and graphene significantly promoted the interfacial electron and lithium ion transport. When used as a binder-less and free-standing electrode for lithium-ion batteries, the hybrid film delivered a high specific capacity (∼1400 mA h g⁻¹ at 100 mA g⁻¹ based on the total electrode weight), enhanced rate capability and excellent cyclic stability (∼1200 mA h g⁻¹ at 200 mA g⁻¹ after 100 cycles). This effective strategy will provide new insight into the design and synthesis of many other composite electrodes for high-performance lithium-ion batteries.