Hard carbon/Li2.6Co0.4N composite anode materials for Li-ion batteries

Hard carbon/Li2.6Co0.4N composite anode electrode is prepared to reduce the initial high irreversible capacity of hard carbon, which hinders potential application of hard carbon in lithium ion batteries, by introducing Li2.6Co0.4N into hard carbon. Lithiated Li2.6Co0.4N provides the compensation of lithium in the first cycle, leading to a high initial coulombic efficiency of ca. 100% versus lithium. As-prepared hard carbon/Li2.6Co0.4N composite electrode presents initial capacity of 438 mA h g− 1. A full cell using LiCoO2 cathode and the composite anode shows much higher initial coulombic efficiency and capacity than those of a cell using LiCoO2 and hard carbon anode. This paves the way to reduce the large initial irreversible capacity of hard carbon.