Enabling the High‐Voltage Operation of Layered Ternary Oxide Cathodes via Thermally Tailored Interphase
Zhiqiang Zhu, Shengkai Cao, Xiang Ge, Shibo Xi, Huarong Xia, Wei Zhang, Zhisheng Lv, Jiaqi Wei, Xiaodong Chen
Abstract
Abstract Layered ternary oxides LiNi x Mn y Co z O 2 are promising cathode candidates for high‐energy lithium‐ion batteries (LIBs), but they usually suffer from the severe interfacial parasitic reactions at voltages above 4.3 V versus Li + /Li, which greatly limit their practical capacities. Herein, using LiNi 1/3 Mn 1/3 Co 1/3 O 2 (NMC111) as the model system, a novel high‐temperature pre‐cycling strategy is proposed to realize its stable cycling in 3.0−4.5 V by constructing a robust cathode/electrolyte interphase (CEI). Specifically, performing the first five cycles of NMC111 at 55 ° C helps to yield a uniform CEI layer enriched with fluorine‐containing species, Li 2 CO 3 and poly(CO 3 ), which greatly suppresses the detrimental side reactions during extended cycling at 25 ° C, endowing the cell with a capacity retention of 92.3% at 1C after 300 cycles, far surpassing 62.0% for the control sample without the thermally tailored CEI. This work highlights the critical role of temperature on manipulating the interfacial properties of cathode materials, opening a new avenue for developing high‐voltage cathodes for Li‐ion batteries.