Understanding the Role of Dopant Metal Atoms on the Structural and Electronic Properties of Lithium Rich Li1.2Ni0.2Mn0.6O2 Cathode Material for Li-Ion Batteries.
Understanding the Role of Dopant Metal Atoms on the Structural and Electronic Properties of Lithium Rich Li1.2Ni0.2Mn0.6O2 Cathode Material for Li-Ion Batteries.
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DOI：
10.1021/acs.jpclett.9b01516
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发表时间：
2019-08
期刊：
影响因子：
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通讯作者：
Wen-Tse Lo;Ching-Ching Yu-Ching;E. G. Leggesse;S. Nachimuthu;Jyh‐Chiang Jiang
中科院分区：
文献类型：
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作者：
Wen-Tse Lo;Ching-Ching Yu-Ching;E. G. Leggesse;S. Nachimuthu;Jyh‐Chiang Jiang
提高富锂正极材料的稳定性对提高锂离子电池的整体性能具有重要意义。本文提出在Li1.2Ni0.2Mn0.6O2的不同位置掺杂K+、Ca2+、Cd2+和Al3+等不同的金属原子，并利用第一性原理计算研究了它们的结构和电子性质。我们发现，原始Li1.2Ni0.2Mn0.6O2结构中的Ni离子在长时间循环过程中保持3+氧化态的时间较长，导致结构变形。而在Cd、K和ca掺杂的Li1.2Ni0.2Mn0.6O2结构中，Ni离子处于3+氧化态的时间较短。我们的DFT结果表明，与原始原子和其他掺杂原子相比，在Li1.2Ni0.2Mn0.6O2的Ni位点掺杂Cd离子是最合适的掺杂方式，因为它抑制了结构变化，降低了形成能，抑制了Jahn-Teller畸变。这一理论研究为研究掺杂策略提供了新的思路，有助于提高富锂阴极材料的电化学性能。
Improving the stability of lithium rich cathode materials is important in refining the overall performance of Lithium ion batteries. Here, we have proposed doping of different metal atoms such as K+, Ca2+, Cd2+, and Al3+ in different sites of Li1.2Ni0.2Mn0.6O2 and investigated their structural and electronic properties using first principles calculations. We found that the Ni ions in the pristine Li1.2Ni0.2Mn0.6O2 structure maintained the 3+ oxidation state for a longer time and resulted in the structural deformation during the long cycling process. Whereas, the Ni ions in the Cd, K and Ca-doped Li1.2Ni0.2Mn0.6O2 structure are in the 3+ oxidation state for a very short time compared to pristine. Our DFT results show that the doping of Cd ion in Ni site of Li1.2Ni0.2Mn0.6O2 is the most suitable one because it inhibits the structural change, lowers the formation energy, suppresses the Jahn-Teller distortion compared with pristine and other dopant atoms. This theoretical study gives new insight about doping strategy and will help in improving the electrochemical performance of Li-rich cathode materials.