Graphene aerogel encapsulated Co3O4 microcubes derived from prussian blue analog as integrated anode with enhanced Li-ion storage properties

Abstract

In lithium-ion batteries (LIB), cobalt oxide is considered an ideal anode material because of its theoretical specific capacity of up to 890 mAh g−1, abundant resources, and low price. However, the volume expansion during the charging and discharging process and its lower conductivity have hindered its development. In this work, a metal-organic framework (MOF) was used as an initial template, encapsulated in graphene aerogels (GA) by hydrothermal and programmed temperature-controlled annealing and eventually formed into Co3O4 microcubes@GA composite. GA acts as a three-dimensional conductive network and mechanical skeleton, providing high electrical conductivity and structural stability to the composites. Moreover, the precursor's high porosity and stable structure are retained after annealing treatment. As an anode, the best long cycle life of Co3O4 microcubes@GA was achieved when the graphene oxide (GO) concentration was 3.0 mg ml−1, reaching 1234.9 mAh g−1 after 200 cycles at 1 A g−1 with a coulomb efficiency (CE) of 98.97%.