PNNL

Abstract

The major roadblocks that plague the large-scale deployment of Ni-rich NMC (LiNixMnyCo1-x-yO2, x = 0.6) cathodes include sensitivity to moisture, side reactions and gas generation, all of which initiate from materials surfaces. Reducing surface areas of Ni-rich cathode i.e., single crystalline NMC has therefore gained intensive interest in recent years. However, fundamental understanding is lacking on the relationship among over potential, microstructure and electrochemical behaviors in single crystalline Ni-rich NMC. This work provides direct observations of planar gliding and cracking along (003) direction in single crystal Ni-rich NMC, which is then correlated to the localized tensile stress induced by concentration gradient of Li+ in the lattice, providing new insights in understanding and tailoring the properties of high-performance single crystalline cathode materials for next-generation Li-ion batteries.