Nickel-rich layered transition metal oxides are leading cathode candidates for lithium-ion batteries due to their increased capacity, low cost and enhanced environmental sustainability. However, nickel enrichment leads to larger volume change during cycling and reduced oxygen stability, causing performance degradation. This study introduces an ultrahigh-nickel cathode, LiNi0.94Co0.05Te0.01O2, addressing these issues by incorporating high-valent tellurium cations (Te4+). The material exhibits an initial capacity of 239 mAh g−1 and 94.5% capacity retention after 200 cycles. A lithium metal battery with a silicon-carbon anode achieves an energy density of 404 Wh kg−1 with 91.2% retention after 300 cycles. Characterizations and calculations show that tellurium engineers particle morphology and enables an ordered superstructure, tuning the energy-level structure and suppressing oxygen loss.

Tonghuan Yang, Kun Zhang, Yuxuan Zuo, Jin Song, Yali Yang, Chuan Gao, Tao Chen, Hangchao Wang, Wukun Xiao, Zewen Jiang, Dingguo Xia