Stabilizing P3‐Type Oxides as Cathodes for High‐Rate and Long‐Life Sodium Ion Batteries by Disordered Distribution of Transition Metals
Stabilizing P3‐Type Oxides as Cathodes for High‐Rate and Long‐Life Sodium Ion Batteries by Disordered Distribution of Transition Metals
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DOI：
10.1002/smtd.202000422
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发表时间：
2020-10
期刊：
影响因子：
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通讯作者：
Li Zhang;Jun Wang;G. Schuck;Fanxing Xi;Leilei Du;M. Winter;G. Schumacher;Jie Li
中科院分区：
文献类型：
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作者：
Li Zhang;Jun Wang;G. Schuck;Fanxing Xi;Leilei Du;M. Winter;G. Schumacher;Jie Li
作为钠离子电池潜在的正极材料，层状NaxTMO2(0.44≤x≤1，TM=过渡金属)材料具有较高的比容量，但循环性能和倍率性能较差。在层状NaxTMO2中，Tm在晶位的分布决定了Tm与配位原子之间的静电相互作用，影响了电化学行为。本文研究了TMS有序排列和无序排列的P3型Na0.67Mn0.67Ni0.33O2材料在不同速率下的循环性能。与TM有序材料不同，无序材料可以在2000 mA g−1下循环1500次，容量保持率为89%。用X射线吸收光谱从局域结构变化的角度解释了TM型无序P3型Na0.67Mn0.67Ni0.33O2循环寿命长的原因。实验结果表明，与Tm有序材料相比，Tm无序材料中NiO6单元的结构稳定性是其循环性能较好的原因。
As potential cathodes for sodium ion batteries, layered NaxTMO2(0.44 ≤x≤ 1, TM = transition metal) materials show high specific capacities but poor cycling and rate performance. In layered NaxTMO2, the distribution of TM at crystal sites determines the electrostatic interaction between TM and the coordinated atoms and affects the electrochemical behavior. Herein, the cycling performance of P3‐type Na0.67Mn0.67Ni0.33O2materials with ordered and disordered arrangement of TMs is investigated at different rates. Unlike the TM‐ordered material, the disordered one can be cycled at 2000 mA g−1for 1500 cycles with 89% capacity retention. X‐ray absorption spectroscopy is performed to elucidate the reason for long cycle life of the TM‐disordered P3‐type Na0.67Mn0.67Ni0.33O2from the sight of local structural changes around Mn and Ni. The experimental results show that the structural stability of NiO6units in the TM‐disordered material is responsible for its better cycling performance in comparison with that of the TM‐ordered material.