Understanding Performance Differences from Various Synthesis Methods: A Case Study of Spinel LiCr0.2Ni0.4Mn1.4O4 Cathode Material
Understanding Performance Differences from Various Synthesis Methods: A Case Study of Spinel LiCr0.2Ni0.4Mn1.4O4 Cathode Material
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了解不同合成方法的性能差异：以尖晶石 LiCr0.2Ni0.4Mn1.4O4 正极材料为例
DOI：
10.1021/acsami.6b08327
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发表时间：
2016
期刊：
影响因子：
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通讯作者：
Dou Shi-Xue
中科院分区：
文献类型：
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作者：
Chen Mingzhe;Hu Zhe;Wu Zhenguo;Hua Weibo;Ozawa Kiyoshi;Gu Qinfen;Kang Yong-Mook;Guo Xiaodong;Chou Shu-Lei;Dou Shi-Xue
高电压（5V级）尖晶石LiCr0.2Ni0.4Mn1.4O4是最有希望满足电动汽车和混合动力汽车锂离子电池能量需求的正极材料之一。对于这种材料的大规模生产（1 kg或更高），不同的合成路线会导致不同的电化学性能，即使是从实验室X射线衍射获得的相似的形貌和相似的晶体结构，也仍然不清楚这个问题的原因。在此，我们已经调查了不同的电化学性能的原因，从三个常见的合成路线（喷雾热解，共沉淀，溶胶-凝胶）。利用同步辐射X射线衍射中的高分辨率X射线束，我们发现，变化的相组成和产生的杂质，而不是颗粒分布，可能是检测到的电化学变化的主要原因。较高量的杂质将导致较大的电荷转移电阻、较差的循环稳定性和更多的氧/锂空位。因此，借助更高分辨率的X射线获得更深入的了解，并为这种阴极材料的实际应用提供更好的指导是非常重要的。
High voltage (5-V class) spinel LiCr0.2Ni0.4Mn1.4O4is one of the most promising cathode materials to meet the energy requirements of lithium-ion batteries for electric vehicles and hybrid electric vehicles. For the mass production of this material (1 kg or higher), different synthesis routes will lead to different electrochemical performances, even with similar morphology and similar crystal structure obtained from laboratory X-ray diffraction, and the reason for this issue is still not clear. Herein, we have investigated the reasons for the different electrochemical performances resulting from three common synthesis routes (spray pyrolysis, coprecipitation, and sol–gel). Taking advantage of the high-resolution X-ray beam in synchrotron X-ray diffraction, we find that varying phase composition and the generated impurities, rather than the particle distribution, are likely to be the main reasons for the detected electrochemical variations. A higher amount of impurities will result in greater charge transfer resistance, inferior cycling stability, and more oxygen/lithium vacancies. Therefore, it is very important to obtain a deeper understanding with the help of higher-resolution X-rays and to provide better guidance for mass production of this cathode material for practical applications.