Li_1.4Al_0.4Ti_1.6(PO₄)₃‑Modified\nLi₄Ti₅O₁₂ Anode for Lithium-Ion Storage\nwith Enhanced Rate and\nCycling Performance

Abstract

The capacity of Li₄Ti₅O₁₂ (LTO)\nat high rates is limited due to the polarization caused by its modest\nLi-ion (Li⁺) diffusion coefficient and low electrical conductivity.\nCoating with ionic conductors is an available method to ameliorate\ncharge transport. Li_1+<i>x</i>Al_<i>x</i>Ti_2–<i>x</i>(PO₄)₃ ion conductors with thermal, chemical, and electrochemical\nstabilities have been proven to be modification materials for electrodes.\nHerein, the Li_1.4Al_0.4Ti_1.6(PO₄)₃ (LATP) precursor dispersion with optimized preparation\nis applied to the surface modification of LTO by a dynamic mix-drying\nmethod. A proper amount of LATP ultrafine particle coating could develop\nthe ion transport rate in the electrode and restrain side reactions.\nThe 2 wt % LATP–LTO anode exhibits an optimized capacity of\n168.2 mA h g^–1 at 0.1 A g^–1 and\nretains 96.7% of its capacity after 5000 cycles at 5.0 A g^–1, while the P-LTO anode retains 86.3% of the capacity. Improved Li⁺ transport and interface stability in the electrodes lead\nto the boosted rate and cycling stability. The LATP-modified LTO composites\nprovide a possibility for the further application of related materials\nin the energy storage field.