A boron-nitride based dispersive composite coating on nickel-rich layered cathodes for enhanced cycle stability and safety
Journal
Journal of Materials Chemistry A
Date Issued
2023-01-01
Author(s)
Chen, Hsi
Chen, Yan Cheng
Liu, Hao Wen
Chang, Shu Jui
Liao, Cheng Hung
Parthasarathi, Senthil Kumar
Bolloju, Satish
Weng, Yu Ting
Lee, Jyh Fu
Chen, Jin Ming
Sheu, Hwo Shuenn
Pao, Chih Wen
Abstract
While Ni-rich cathodes have been widely adopted in high-energy lithium-ion batteries, there remains room for improvement regarding their cycle stability and safety. Herein, hexagonal boron nitride (h-BN) is demonstrated, for the first time, to be an effective surface modification additive for Ni-rich cathodes. The h-BN coated Ni-rich cathode, prepared via a rapid low-temperature post-calcination process, shows markedly improved cycle stability and safety with only a trace amount of h-BN being added (1 wt% relative to the cathode oxide). Systematic synchrotron post-mortem and operando X-ray analyses reveal that the improvements could be attributed to the anion-trapping ability of the B atoms in h-BN, which mitigates surface Ni-ion reduction and carbonate accumulation caused by electrolyte corrosion during both cycling and thermal runaway. Furthermore, the high thermal conductivity of h-BN contributes to efficient heat dissipation during the early stages of thermal runaway and therefore delays the onset temperature. This work identifies h-BN as well as the concept of “anion-trapping” as promising strategies for enhancing the cycle life and safety of Ni-rich cathodes and presents an industrially facile method to accomplish such applications.
Type
journal article