The enhanced high cut-off voltage electrochemical performances of LiNi 0.5 Co 0.2 Mn 0.3 O 2 by the CeO 2 modification
The enhanced high cut-off voltage electrochemical performances of LiNi 0.5 Co 0.2 Mn 0.3 O 2 by the CeO 2 modification
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DOI：
10.1016/j.electacta.2016.09.139
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发表时间：
2016-11
影响因子：
6.6
通讯作者：
Yan Xu;Xinhai Li;Zhixing Wang;Huajun Guo;W. Peng;Wei Pan
中科院分区：
文献类型：
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作者：
Yan Xu;Xinhai Li;Zhixing Wang;Huajun Guo;W. Peng;Wei Pan
用共沉淀法分别以碳酸铵和草酸铵为沉淀剂制备了分散在商品LiNi0.5Co0.2Mn0.3O2表面的CeO2纳米粒子，生成不同的CeO2前驱体。以草酸铵为沉淀剂的CeO2改性LiNi0.5Co0.2Mn0.3O2复合材料具有最好的电化学性能，其可逆储锂容量为157.7−1，在25°C、电流密度1C下循环100次后，在高截止电压4.6V下循环100次，保持率为86.36%；在55℃高温下，其放电容量从198.2 mAhg−1变为136.6 mAhg−1,100次循环后，保持率为68.29%。此外，在第100次循环中，它还表现出优异的倍率性能，在5C时容量为114.0毫安−1。这些性能的提高可能是由于CeO2在工业LiNi0.5Co0.2Mn0.3O2表面的分散以及CeO2与LiNi0.5Co0.2Mn0.3O2之间的协同作用，从而提高了结构稳定性和导电性。
The CeO2nano-particles dispersed on the surface of commercial LiNi0.5Co0.2Mn0.3O2, have been prepared by a co-precipitation method, in which ammonium carbonate or ammonium oxalate is served as a precipitant to generate the different precursor of CeO2, respectively. CeO2-modified LiNi0.5Co0.2Mn0.3O2composites with ammonium oxalate as the precipitant exhibit the best electrochemical properties with a reversible lithium storage capacity of 157.7 mAh g−1with a retention of 86.36% at 25 °C at the current density 1C after 100 cycles under high cut-off voltage 4.6 V. At higher temperature 55 °C, its discharge capacity changes from 198.2 mAh g−1to 136.6 mAh g−1after 100 cycles, with a retention of 68.29%. Besides, it also displays an excellent rate performance with a capacity of 114.0 mAh g−1at 5C in the 100th cycle. All enhanced performances could be due to the dispersion of CeO2on the surface of commercial LiNi0.5Co0.2Mn0.3O2and the synergistic effects between the CeO2and LiNi0.5Co0.2Mn0.3O2, which leads to the enhanced structural stability and electric conductivity.