Improvement of the high-temperature, high-voltage cycling performance of LiNi0.5Co0.2Mn0.3O2 cathode with TiO2 coating
Improvement of the high-temperature, high-voltage cycling performance of LiNi0.5Co0.2Mn0.3O2 cathode with TiO2 coating
复制标题
DOI：
10.1016/j.jallcom.2012.07.074
复制
发表时间：
2012-12
影响因子：
6.2
通讯作者：
Wen Liu;Miao Wang;Xingyue Gao;Weidong Zhang;Jitao Chen;Henghui Zhou;Xinxiang Zhang
中科院分区：
文献类型：
--
作者：
Wen Liu;Miao Wang;Xingyue Gao;Weidong Zhang;Jitao Chen;Henghui Zhou;Xinxiang Zhang
TiO 2包覆提高了LiNi 0. 5Co 0. 2 Mn 0. 3 O2在高截止电压下的高温循环稳定性。通过电化学阻抗谱（EIS）、X射线光电子能谱（XPS）和电感耦合等离子体原子发射光谱（ICP-AES）分析阐明了增强机理。TiO 2包覆在LiNi 0. 5Co 0. 2 Mn 0. 3 O2颗粒表面形成了一层均匀的包覆层，且未改变其晶体结构。电化学测试结果表明，TiO 2涂层能够提高328 K和4.4V高截止电压下的锂离子嵌入稳定性。包覆1.0%TiO2的LiNi0.5Co0.2Mn0.3O2在0.5C下循环100次后的放电容量为149.2mAhg− 1，并保持初始放电容量的92.1%。相比之下，裸样品放电仅为87.7mAhg− 1，容量保持率为48.2%。ICP-AES结果表明，TiO 2包覆层可以减少LiNi 0. 5Co 0. 2 Mn 0. 3 O2中过渡金属离子的溶出。电化学阻抗谱（EIS）和X射线光电子能谱（XPS）分析表明，锂离子电池正极与电解液之间的反应得到了抑制，从而提高了电池的循环稳定性。
The high-temperature cycling stability at a high cutoff voltage of LiNi0.5Co0.2Mn0.3O2was improved by TiO2coating. The mechanism of enhancement was elucidated by electrochemical impedance spectroscopy (EIS), X-ray photoelectron spectroscopy (XPS), and inductively coupled plasma-atomic emission spectroscopy (ICP-AES) analyses. TiO2coating formed a uniform layer on the surface of LiNi0.5Co0.2Mn0.3O2particles without changing the crystal structure. Electrochemical tests indicated that TiO2coating can improve the lithium ion intercalation stability at 328K and at a high cutoff voltage of 4.4V. The 1.0% TiO2-coated LiNi0.5Co0.2Mn0.3O2discharged 149.2mAhg−1after 100 cycles at 0.5C, and maintained 92.1% of the initial discharge capacity. By contrast, the bare sample discharged only 87.7mAhg−1with 48.2% capacity retention. ICP-AES results proved that the TiO2coating layer can reduce the dissolution of transition metal ions from LiNi0.5Co0.2Mn0.3O2. EIS and XPS confirmed that the improved cycling stability can be attributed to the suppression of the reaction between cathode and electrolyte in lithium-ion batteries.