High Lithium Storage Performance of Co Ion-Doped Li₄Ti₅O₁₂ Induced by Fast Charge Transport

In this study, Co₃O₄-doped Li₄Ti₅O₁₂ (LTO) composite was designed and synthesized by the hydrothermal reduction method and metal doping modification method. The microstructure and electrochemical performance of the Co₃O₄-doped Li₄Ti₅O₁₂ composite were characterized by XRD, SEM, TEM, electrochemical impedance spectroscopy, and galvanostatic tests. The results showed that Li₄Ti₅O₁₂ particles attached to lamellar Co₃O₄ constituted a heterostructure and Co ion doped into Li₄Ti₅O₁₂ lattice. This Co ion-doped microstructure improved the charge transportability of Li₄Ti₅O₁₂ and inhibited the gas evolution behavior of Li₄Ti₅O₁₂, which enhanced the lithium storage performance. After 20 cycles, the discharge specific capacity reached stability, and the capacity retention maintained 99% after 1,000 cycles at 0.1 A/g (compared to the capacity at the 20th cycle). It had an excellent rate performance and long cycle stability, in which the capacity reached 174.6 mA h/g, 2.2 times higher than that of Li₄Ti₅O₁₂ at 5 A/g.