Hexagonal boron nitride incorporation to achieve high performance Li4Ti5O12 electrodes

Abstract

There is an increasing demand for fast charging and high capacity lithium ion batteries. However, conventional Li-ion battery chemistries cannot meet the stringent requirements of these demands due to the poor performance of graphite anodes, especially on safety during fast charging. Finding the right anode material that can replace conventional graphite while providing high capacity is very challenging. Today, lithium titanium oxide (LTO) is considered one of the most attractive anode materials that can provide the desired ultra-fast charging ability (>10C) with high safety. However, it has many serious drawbacks when compared to the existing graphite anodes, including poor intrinsic conductivity, narrow electrochemical window, etc. Extensive research has been done to overcome these problems, especially in developing new LTO composite materials with reduced graphene oxide. However, even these methods have rapid capacity fading at high current densities, >5C, due to increased internal resistance and polarization losses. Here, we demonstrate an effective way to improve LTO composite materials by developing unique nanoengineered three-dimensional frameworks with hexagonal boron nitride (h-BN) addition. Li-ion cells with h-BN incorporation exhibit excellent performance and operational stability, especially at fast and ultra-fast charging rates, >10C.