High Performance LiNi0.5Mn1.5O4 Spinel Li-Ion Battery Cathode Development

Abstract

Due to its high theoretical capacity (147 mAh/g), high operating voltage (~4.7V vs. Li/Li+ of Ni2+/Ni4+ couple), and inherent cycle stability (Mn4+ state, no Jahn-Teller distortion of Mn3+), LiNi0.5Mn1.5O4 (LNMO) spinel is a promising cathode active material for high energy density lithium ion batteries [1, 2, 3] that can potentially be used in a wide range of applications including consumer electronics, electric vehicles, military and space. However, some performance issues of LNMO need to be addressed before its practical commercialization. These include extended cycle life, high rate capability, and cycle stability at elevated temperatures (e.g. 55°C).Here we report efforts at ADA Technologies, Inc. to optimize LiNi0.5Mn1.5O4 (LNMO) spinel performance via material and operational approaches. In addition to improved stability with the electrolyte [4], oxide coatings applied via atomic layer deposition (ALD) technique are used to address cycle stability of LNMO at high temperatures.