The evolution in electrochemical performance of Li4-XCaxTi5O12 (Ca doped Li4Ti5O12) as anode materials for lithium ion batteries

Doping elements play an important role in improving the conductivity of Li 4 Ti 5 O 12 used as anode materials for lithium ion batteries . In this work, nanoparticles of Li 4-X Ca x Ti 5 O 12 (x = 0, 0.03, 0.05 and 0.07) were successfully synthesized through a facile hydrothermal method followed by calcination . The evolution in microstructure as well as electrochemical performance of the modified samples with the doped Ca content were investigated in details. It was found that modified Li 4-x Ca x Ti 5 O 12 (x = 0.05) exhibited the best electrochemical performances in terms of the highest initial specific discharge capacity (158.55 mA h g −1 at 160 mA g -1 ), best cycling stability with a retained specific charge capacity of 104.76 mAh g −1 at 160 mA g -1 after 100 cycles and rating capability with a retained rate of 64.55 %/88.56 % with the current density drastically increased 1600 mA⋅ g −1 and dropped to initial value. The excessive introduction of Ca (x = 0.07) caused the sharp decrease in electrochemical performance due to the formation of inert and insulating CaCO 3 . Li 4-x Ca x Ti 5 O 12 (x = 0.05) also demonstrated a lowest ohmic resistance (2.35 Ω) and charge transfer resistance (95.42 Ω).