High capacity graphite-like calcium boridecarbides as a novel anode active material for lithium-ion batteries

Abstract

Graphite-like Ca_0.6B_1.2C_4.8 is reported as a novel anode active material for lithium-ion batteries. Its original specific capacity was 552 mA h g⁻¹, and it was increased to 648 mA h g⁻¹, which is 1.7 times higher than that of graphite, by preliminary extraction of a portion of its calcium atoms. The average lithium deintercalation potential was 1.16 V vs. Li/Li⁺, which is one of the lowest-ever potential values among high capacity carbon-based materials studied so far. We also reveal its unique Li intercalation/deintercalation behavior coincident with a 7% change in the boron-doped graphene interlayer distance while keeping its ordered layer structure. This is the first development of a high capacity and low potential carbon based material which is capable of being prepared by one-pot heat treatment from graphite showing graphite-like reversible structural changes upon Li intercalation/deintercalation.