Electrochemical study of Li4Ti5O12 as negative electrode for Li-ion polymer rechargeable batteries

Li4Ti5O12 a zero-strain insertion material was prepared by conventional method and by high energy ball milling (HEBM) of precursor to form nanocrystalline phases. The electrochemical performance of solid-state negative electrode was carried out using a solvent-free solid polymer electrolyte at 60°C and 80°C. A Li4Ti5O12 vs. lithium cell discharged at C/12 delivered 155 mA h g−1 for the conventional method and 157 mA h g−1 for the method using high ball energy milling, corresponding respectively to 97% and 96% first-cycle coulombic efficiency. The chemical diffusion coefficient of Li4Ti5O12 spinel-type compound is about 2×10−8 cm2 s−1. This is one order of magnitude higher than that of carbonaceous negative electrodes. Li4Ti5O12, which is a zero-strain insertion material, offers advantage for the SPE cell including safety, long life, and reliability.