Liu Ruyi, Yang Shujing, Zhou Siteng, Xing Jiaxin, Niu Xinwang, Pang Guoyao, Liu Guicheng, Ye Feng, Xiao Biwei, Xu Chao
Beijing Laboratory of New Energy Storage Technology, School of Energy Power and Mechanical Engineering, North China Electric Power University, Beijing, 102206, China.
GRINM (Guangdong) Research Institute for Advanced Materials and Technology, Foshan, Guangdong, 528051, China.
Small. 2025 Jul 31:e05197. doi: 10.1002/smll.202505197.
O3-type layered cathode materials in sodium-ion batteries exhibit high capacity for their unique crystal structures and high Na content. However, the capacity degradation from irreversible phase transition at the high voltage window, directly limits commercial applications. Herein, Zn-doped O3-NaNiFeMnO (NFM) cathodes are successfully fabricated by regulating reversible phase transition with doping Zn using the high-temperature solid-state method. The optimal NFM-3% Zn achieves highly efficient performance of 84.5 mAh g at 10 C, and the reversible capacity is remarkably up to 83.5 mAh g after 300 cycles at high voltage window of 2.0-4.2 V. The introduction of additional Zn in the TM layer enhances TM─O bonding interactions, expands alkali metal layers and increases layered crystal structure stability. Moreover, the Zn incorporation provides high electron localization, which regulates the reversible O3-P3-OP2-P3'-O3 phase transition of NFM and suppresses the random migration of TM to alkali metal layers. Combined with the results of in situ XRD and density functional theory (D calculations, the phase transition sodium storage mechanism of Zn-doped NFM cathode is investigated in detail. This study provides a modification strategy for O3-type layered cathode materials to improve performance at the high voltage window for sodium-ion batteries.
钠离子电池中的O3型层状阴极材料因其独特的晶体结构和高钠含量而具有高容量。然而，在高电压窗口下不可逆相变导致的容量衰减直接限制了其商业应用。在此，通过高温固态法掺杂锌来调节可逆相变，成功制备了锌掺杂的O3-NaNiFeMnO（NFM）阴极。最佳的NFM-3%Zn在10C下实现了84.5mAh/g的高效性能，在2.0-4.2V的高电压窗口下经过300次循环后，可逆容量显著高达83.5mAh/g。在过渡金属（TM）层中引入额外的锌增强了TM─O键相互作用，扩展了碱金属层并提高了层状晶体结构的稳定性。此外，锌的掺入提供了高电子局域化，从而调节了NFM的可逆O3-P3-OP2-P3'-O3相变，并抑制了TM向碱金属层的随机迁移。结合原位X射线衍射（XRD）和密度泛函理论（DFT）计算结果，详细研究了锌掺杂NFM阴极的相变储钠机理。本研究为O3型层状阴极材料提供了一种改性策略，以提高钠离子电池在高电压窗口下的性能。
