Controlling Surface Phase Transition and Chemical Reactivity of O3-Layered Metal Oxide Cathodes for High-Performance Na-Ion Batteries
Junhua Song, Kuan Wang, Jianming Zheng, Mark Engelhard, Biwei Xiao, Enyuan Hu, Zihua Zhu, Chongmin Wang, Manling Sui, Yuehe Lin, David Reed, Vincent Sprenkle, Pengfei Yan, Xiaolin Li
Abstract
O3-layered metal oxides are promising cathode materials for high-energy Na-ion batteries (SIBs); however, they suffer from fast capacity fade. In this work, we develop a high-performance O3-NaNi<sub>0.68</sub>Mn<sub>0.22</sub>Co<sub>0.10</sub>O<sub>2</sub> cathode for SIBs toward practical applications by suppressing the formation of a rock salt layer at the cathode surface with an advanced electrolyte. The cathode can deliver a high specific capacity of ~196 mAh g<sup>–1</sup> and demonstrates >80% capacity retention over 1000 cycles. NaNi<sub>0.68</sub>Mn<sub>0.22</sub>Co<sub>0.10</sub>O<sub>2</sub>–hard carbon full-cells with practical loading (>2.5 mAh cm<sup>–2</sup>) and lean electrolyte (~40 μL) demonstrate ~82% capacity retention after 450 cycles. A 60 mAh single-layer pouch cell has also been fabricated and demonstrated stable performance. This work represents a significant leap in SIB development and brings new insights to the development of advanced layered metal oxide cathodes for alkaline-ion batteries.