Synthesis and electrochemical characteristics of flower-like Ca-doped Li4Ti5O12 as anode material for lithium-ion batteries

The Ca-doped Li4Ti5O12 (LTO-CA) samples with flower-like morphology, were synthesized by a hydrothermal method and used as anode material for lithium-ion batteries. The results showed that Ca2+ ions were successfully introduced into the structure of LTO, and the flower-like morphology was assembled from a large number of nanosheets. The influence of Ca2+ doping on structure and electrochemical performances of LTO were studied in detail. In addition, the partial valence conversion of Ti4+ into Ti3+ was confirmed in the structure for increasing the electronic conductivity. The electrochemical performance results revealed that the specific discharge capacity was enhanced with the incorporation of Ca2+, and the discharge rate and cycling performance were also improved. In particular, the LTO-CA4 with 0.4% Ca2+ doping had a specific capacity of 196.9 mAh/g under discharge rate of 1C, and the capacity retention rate reached as high as 87.49% after 200 cycles, which indicated the LTO-CA4 had a potential application in lithium-ion batteries as anode material.