T<sup>#</sup>2‐Li<sub>0.69</sub>CoO<sub>2</sub>: A Durable, High‐Capacity, High‐Rate Cathode Material for Lithium‐Ion Batteries
Yuxuan Zuo, Jiahui Liu, Hangchao Wang, Ying Zou, Tie Luo, Kun Zhang, Yali Yang, Chuan Gao, Biao Li, Qiang Sun, Dingguo Xia
Abstract
Abstract Efficient utilization of resources is crucial for the sustainable development of the lithium‐ion battery industry. Although the traditional R m space group LiCoO 2 can provide a current advanced discharge capacity of 215–220 mAh g⁻¹ at an upper cut‐off voltage of 4.6 V (relative to Li⁺/Li), it still falls far short of its theoretical specific capacity of 273 mAh g⁻¹, and exhibits structural instability and labile oxygen loss, leading to rapid capacity degradation. T # 2‐Li 0.69 CoO 2 is synthesized with Cmca space group and Li─O tetrahedral coordination. Owing to the unique Li─O tetrahedral coordination structure and the dominant cobalt oxidation under high voltage, T # 2‐Li 0.69 CoO 2 delivers an ultra‐high specific capacity of 258 mAh g −1 , close to the theoretical capacity, in liquid electrolyte batteries and 253 mAh g −1 in solid state batteries, overcoming the structural instability of layered oxide cathodes during charging and discharging processes. This study broadens the possibilities of creating high energy‐density cathodes for next‐generation Li‐ion batteries.