Anchored CoCO₃ on peeled graphite sheets toward high-capacity lithium-ion battery anode

Transition metal carbonates are attracting significant interests as lithium-ion batteries (LIBs) anode due to their high specific capacity and initial Coulombic efficiency. However, the internal poor conductivity and volume variation hinder their application. In this work, we report an approach to crush CoCO₃ and peel graphite synchronously, in which the crushed CoCO₃ was anchored on peeled graphite sheets via one step ball-milling method. The peeled graphite sheets act as electron conductive layers and can relax the volume expansion/shrink of CoCO₃ during lithiation/de-lithiation. The graphite was peeled to 4.5 layers averagely, and the CoCO₃ was crushed to particles of less than 500 nm simultaneously. CoCO₃ particles play the role of high capacity function material in CoCO₃/graphene (CoCO₃/G) anode. The CoCO₃/G electrode exhibits an initial capacity of 1314 mAh g⁻¹ and 661 mAh g⁻¹ at 200th cycle at 100 mA g⁻¹. Such facile method is promising for obtaining various graphene-anchored composites with improved electrochemical performances.