High-voltage capabilities of ultra-thin Nb2O5 nanosheet coated LiNi1/3Co1/3Mn1/3O2 cathodes

Abstract

In this study, we propose coating the surface of LiNi_1/3Co_1/3Mn_1/3O₂ (NCM) electrodes with 1.1 nm Nb₂O₅ nanosheets as a new way for enhancing their high-voltage capabilities in galvanostatic charge–discharge performances and long-term storage of the charged state at 60 °C. The coatings suppress the oxidative decomposition of the electrolyte and the disordering of the layered structures on the NCM surface, which result in impedance growth. After 100 cycles at voltage ranges 4.6–2.8 V at 1 C rate, more than 70% of the initial discharge capacity was retained in the coated electrodes. In comparison, the discharge capacity completely faded in the bare NCM cathode. Furthermore, the nanosheet coatings stabilize the delithiated NCM lattice charged at 4.6 V and inhibit current generation based on the electrode reactions at 60 °C for 300 h.