Oxygen redox in transition metal oxides enhances the energy content of Na-ion batteries but is typically plagued by poor reversibility. Here, the authors achieve non-hysteresis through the formation of a spin singlet state to stabilize the active oxygen redox reaction in P3-type Na2/3Cu1/3Mn2/3O2.
- Xuelong Wang
- Liang Yin
- Jue Liu
