阴极
兴奋剂
电极
钠离子电池
材料科学
拉曼光谱
电化学
X射线光电子能谱
离子
阳极
密度泛函理论
分析化学(期刊)
化学工程
光电子学
化学
计算化学
工程类
物理
物理化学
有机化学
法拉第效率
色谱法
光学
作者
Huiyu Zhang,Yanhong Xiang,Baocheng Liu,G. Li,Chen Dun,H. K. Huang,Qiuling Zou,Ling Xiong,Xianwen Wu
标识
DOI:10.1016/j.jcis.2024.01.165
摘要
Due to its stability and low cost, the tunnel-style sodium-manganese oxide (Na0.44MnO2) material is deemed a popular cathode choice for sodium-ion rechargeable batteries. However, the Jahn-Teller effect caused by Mn3+ in the material results in poor capacity and cycling stability. The purpose of this experimental study is to partially replace Mn3+ with Fe3+, in order to reduce the Jahn-Teller effect of the material during charging and discharging process. The results of Raman spectroscopy and X-ray photoelectron spectroscopy confirmed that the content of Mn3+ decreased after Fe3+ doping. Electrochemical studies show that the Na0.44Mn0.994Fe0.006O2 cathode has better rate performance (exhibits a reversible capacity of 87.9 mAh/g at 2 C) and cycle stability in sodium-ion batteries. The diffusion coefficient of sodium ions increases by Fe3+ doping. The excellent rate performance and capacity improvement are verified by density functional theory (DFT) calculation. After doping, the band gap decreases significantly, and the results show that the state density of O 2p increases near the Fermi level, which promotes the oxidation–reduction of oxygen. This work provides a straightforward approach to enhance the performance of Na0.44MnO2 nanorods, and this performance improvement has guiding significance for the design of other materials in the energy storage domain.
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