Chen, HsiHsiChenChen, Yan ChengYan ChengChenLiu, Hao WenHao WenLiuChang, Shu JuiShu JuiChangLiao, Cheng HungCheng HungLiaoParthasarathi, Senthil KumarSenthil KumarParthasarathiBolloju, SatishSatishBollojuWeng, Yu TingYu TingWengLee, Jyh FuJyh FuLeeChen, Jin MingJin MingChenSheu, Hwo ShuennHwo ShuennSheuPao, Chih WenChih WenPaoNAE-LIH WU2023-07-202023-07-202023-01-0120507488https://scholars.lib.ntu.edu.tw/handle/123456789/633977While 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.[SDGs]SDG7[SDGs]SDG11journal article10.1039/d3ta01500a2-s2.0-85162264154https://api.elsevier.com/content/abstract/scopus_id/85162264154