Separator with active coating for fast and stable Li-ion batteries

Abstract

Li-ion batteries are widely used in various applications, but their performance is limited by the stability and capacity of the separator. Developing a separator that can prevent thermal runaway and provide additional capacity is a significant challenge in battery research. In this study, a novel method of applying a Lithium titanate (LTO) active coating on the separator of Li-ion batteries is proposed. The LTO active coating can participate in electrochemical reactions and provide additional capacity. The active coating also improves the separator stability by preventing thermal shrinkage and enhancing thermal stability. The active coating has little impact on the Li-ion diffusion, and enables fast and stable battery performance at high C rates. The separator with active coating exhibits the highest ionic conductivity of 1.45 mS/cm, the lowest thermal shrinkage of 1.1% at 160 °C, and the highest capacity of 80.2 mAh/g at 15 C among the tested separators. This method offers a simple and effective way to enhance the performance of Li-ion batteries.