Qin CanCan, Cao JiaLi, Chen Jun, Dai GaoLe, Wu TongFu, Chen Yanbin, Tang YueFeng, Li AiDong, Chen Yanfeng
National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, Nanjing University, Nanjing, Jiangsu 210093, China.
Dalton Trans. 2016 Jun 21;45(23):9669-75. doi: 10.1039/c6dt01764a. Epub 2016 May 26.
LiNi0.6Co0.2Mn0.2O2 cathode material has been surface-modified by coating with ultrathin TiO2via atomic layer deposition (ALD) technology to improve the electrochemical performance of LiNi0.6Co0.2Mn0.2O2 cathodes for lithium ion batteries. Within the cut-off voltage of 2.5-4.3 V, the coated sample delivers an initial discharge capacity of 187.7 mA h g(-1) at 0.1 C and with a capacity retention about 85.9% after 100 cycles at 1 C, which provides a significant improvement in terms of discharge capacity and cyclability, as compared with those of the bare one. Such enhanced electrochemical performance of the coated sample is ascribed to its high-quality ultrathin coating of amorphous TiO2, which can protect the active material from HF attack, withstand the dissolution of metal ions in the electrode and favor the lithium diffusion of oxide as proved by electrochemical impedance spectroscopy (EIS) tests. TiO2 coating via the ALD process provides a potential approach for battery factories to surface-modify Ni-rich electrode materials so as to realize improvements in electrochemical performance.
通过原子层沉积（ALD）技术在LiNi0.6Co0.2Mn0.2O2正极材料表面包覆超薄TiO2进行表面改性，以提高锂离子电池LiNi0.6Co0.2Mn0.2O2正极的电化学性能。在2.5-4.3V的截止电压范围内，包覆样品在0.1C下的初始放电容量为187.7 mA h g(-1)，在1C下循环100次后的容量保持率约为85.9%，与未包覆样品相比，其放电容量和循环稳定性有显著提高。包覆样品电化学性能的增强归因于其高质量的非晶态TiO2超薄涂层，电化学阻抗谱（EIS）测试表明，该涂层可以保护活性材料免受HF侵蚀，抵抗电极中金属离子的溶解，并有利于氧化物的锂扩散。通过ALD工艺包覆TiO2为电池工厂对富镍电极材料进行表面改性以实现电化学性能的提升提供了一种潜在的方法。
