The Presence of Copper Oxide (CuO) Enabled the High‐Rate Performance of the Commercial Lithium Titanate (LTO) in Half‐ and Full‐Cell Experiments

For the first time, a copper oxide (CuO)‐containing lithium titanate (Li 4 Ti 5 O 12 , LTO) is prepared via an air annealing approach in which copper oxalate (CuC 2 O 4 ) and the commercial LTO are employed as the starting materials. As demonstrated by the X‐ray diffractometer and X‐ray photoelectron spectroscopy characterization results, CuO and LTO are indicated to be the main components of all prepared samples. Above all, all prepared samples, especially sample b, exhibit much better electrochemical performance than the commercial LTO. Particularly, the high‐rate performances delivered by all synthesized samples, especially sample b, are significantly superior to that of the commercial LTO. For instance, the discharge capacity of sample b at 40 C after 500 cycles is about 40 mAh g −1 , which is about 14.8 times higher than that of the commercial LTO (2.7 mAh g −1 ). In the full‐cell test, the discharge capacity of the cell assembled by sample b and the modified lithium iron phosphate (LiFePO 4 , LFP) at 10 C after 500 cycles (40.3 mAh g −1 ) is significantly larger than that of the full‐cell assembled by the commercial LTO and the modified LFP (0.1 mAh g −1 ).