Investigating the Origin of Cation Mixing in Nickel Rich Cathodes

Abstract

*corresponding authors email: muralidharan@ornl.gov and belharouaki@ornl.gov Lithium Ion Batteries Have Been the Catalyst That Brought about the Revolution of Portable Electronic Devices and Electric Vehicles. with the Ever-Increasing Promise of Novel Anode Formulations Delivering Higher Capacities, the Present-Day Energy Densities Are Limited By the Choice of Cathode Used. with Recent Research and Development Trends Focused Heavily on the Class of Layered Nickel Rich Cathodes (LiNixM1-xO2, where M=Transition Metal Cation, x>0.6), It Is of Categorical Importance to Understand the Limiting Mechanisms Hampering the Performance of Such Cathode Systems. of Particular Importance Is the Intermixing of Cations, Ni2+ and Li+ between the Lithium and Transition Metal Slabs in These Layered Cathodes Owing to Their Similar Ionic Radii. These Ni2+ions in the Lithium Slab Creates Li+ Ion Migration Bottlenecks Thus Resulting in the Under-Utilization of the Total Available Storage Capacity of These Cathode Materials. Our Work, Utilizing in-Situ X-Ray Diffraction and Mossbauer Spectroscopy during the Synthesis Procedures Aims to Reveal the Role of Specific Transition Metal Cation Dopants in Lowering/Increasing the Extent of Cation Mixing and the Resulting Electrochemical Behavior of Nickel Rich Cathode Systems Such As the LiNi0.8CoxAlyO2(NCA class) and the LiNi0.8CoxMnyO2 (NCM class). Overall, This Work Provides a Broad Framework to Understand, Isolate and Mitigate This Limiting Phenomena in the Development of Next Generation Lithium Ion Battery Cathodes.