High-Energy W-Doped Li[Ni0.95Co0.04Al0.01]O2 Cathodes for Next-Generation Electric Vehicles

Abstract

The lithiated nickel-cobalt-aluminum oxide (Li[Ni0.8Co0.15Al0.05]O2, NCA) cathode has become commercialized because it provides high discharge capacity with long cycle life. To further increase the capacity of existing NCA cathodes, the fraction of Ni in the NCA cathode has been progressively increased; however, this approach is limited by the deterioration of capacity and safety concerns. Here, we report fundamental electrochemical performances of W-doped Li[Ni0.95Co0.04Al0.01]O2 cathode (W-NCA95) with columnar grains by introducing WS2. The microstructure-modified W-NCA95 delivers a high initial capacity of 242 mAh g–1 (0.1 C) and retains 77.4% of its initial capacity after 1000 cycles, compared to 14.5% for Li[Ni0.95Co0.04Al0.01]O2 cathode (NCA95). The superior cycling performances of the W-NCA95 cathode are attributed to the reduction of the anisotropic volume change and the unique long rod-shaped primary particles morphology. The proposed W-NCA95 cathode paves the way for the development of Ni-rich layered LiMO2 cathodes that can exhibit high capacity, superior cycling stability, and improved thermal stability.