Li Xinxin, Shi Hebang, Wang Bo, Li Na, Zhang Liqiang, Lv Pengpeng
State Key Laboratory of Heavy Oil Processing, China University of Petroleum Beijing Beijing 102249 China.
State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences Beijing 100190 China
RSC Adv. 2019 Jun 7;9(31):17941-17949. doi: 10.1039/c9ra03087e. eCollection 2019 Jun 4.
Surface coating of metal oxides is an effective approach for enhancing the capacity retention of a nickel-rich layered cathode. Current conventional coating techniques including wet chemistry methods and atomic layer deposition are restricted by the difficulty in perfectly balancing the coating quality and scale-up production. Herein, a highly efficient TiO coating route through fluidized bed chemical vapor deposition (FBCVD) was proposed to enable scalable and high yield synthesis of a TiO coated nickel-rich cathode. The technological parameters including coating time and TiCl supply rate were systematically studied, and thus a utility TiO deposition rate model was deduced, promoting the controllable TiO coating. The FBCVD TiO deposition mechanism was fundamentally analyzed based on the TiCl hydrolysis principle. The amorphous and uniform TiO coating layer is compactly attached on the particle surface, forming a classical core-shell structure. Electrochemical evaluations reveal that the TiO coating by FBCVD route indeed improves the capacity retention from 89.08% to 95.89% after 50 cycles.
金属氧化物表面涂层是提高富镍层状正极容量保持率的有效方法。当前的传统涂层技术，包括湿化学方法和原子层沉积，受到难以完美平衡涂层质量和扩大生产规模的限制。在此，提出了一种通过流化床化学气相沉积（FBCVD）的高效TiO涂层路线，以实现可扩展且高产率地合成TiO包覆的富镍正极。系统研究了包括涂层时间和TiCl供应速率在内的工艺参数，从而推导出实用的TiO沉积速率模型，促进了TiO涂层的可控性。基于TiCl水解原理从根本上分析了FBCVD TiO沉积机理。非晶且均匀的TiO涂层紧密附着在颗粒表面，形成经典的核壳结构。电化学评估表明，通过FBCVD路线制备的TiO涂层确实将50次循环后的容量保持率从89.08%提高到了95.89%。
