A scalable ternary SnO2-Co-C composite as a high initial coulombic efficiency, large capacity and long lifetime anode for lithium ion batteries

A new ternary SnO2-Co-C composite is produced using a facile and scalable ball milling method, which has a microstructure that includes refined SnO2-Co hybrids embedded in graphite. The Co additives dramatically inhibit Sn coarsening in the lithiated SnO2, which enables highly reversible conversion reactions in the SnO2-based ternary composite during cycling. The electrodes exhibit high ICEs with an average of 80.8% and a reversible capacity of 780 mA h g(-1) at 0.2 A g(-1) after 400 cycles when the composite was manufactured via small planetary ball milling, and they achieve 875 mA h g(-1) after 250 cycles when the material is prepared on a large-scale with a roller mill. Even at a high rate of 2 A g(-1), the composite has a long lifetime and delivers 610 mA h g(-1) after 1000 cycles. Furthermore, a stable capacity of 410 mA h g(-1) can be also retained in a full cell combined with a LiFePO4 cathode and SnO2-Co-C anode when cycling within 2.3-3.4 V at 0.2C. The new ternary SnO2-Co-C composite demonstrates excellent comprehensive electrochemical performances, and it is a promising candidate anode material for use in practical applications.