Su Yuefeng, Chen Gang, Chen Lai, Li Linwei, Li Cong, Ding Rui, Liu Jiahui, Lv Zhao, Lu Yun, Bao Liying, Tan Guoqiang, Chen Shi, Wu Feng
Beijing Key Laboratory of Environmental Science and Engineering, School of Materials Science and Engineering, Beijing Institute of Technology, Beijing, China.
Beijing Institute of Technology Chongqing Innovation Center, Chongqing, China.
Front Chem. 2020 Jul 24;8:573. doi: 10.3389/fchem.2020.00573. eCollection 2020.
The existence of residual lithium compounds (RLCs) on the surface of layered Ni-rich materials will deteriorate the electrochemical properties and cause safety problem. This work presents an effective surface washing method to remove the RLCs from LiNiCoMnO material surface, ethyl alcohol solution that contains low concentration of boric acid. It is a low-cost process because the filter liquor can be recycled. The optimal parameters including washing time, boric acid concentration, and solid-liquid ratio were systematically studied. It has been determined by powder pH and Fourier transform infrared spectra results that the amount of RLCs was reduced effectively, and the storage performance was significantly enhanced for the washed samples. The 150th capacity retentions after storing had increased from 68.39% of pristine material to 85.46-94.84% of the washed materials. The performance enhancements should be ascribed to the surface washing process, which removed not only the RLCs, but also the loose primary particles effectively.
层状富镍材料表面残留锂化合物（RLCs）的存在会使电化学性能恶化并引发安全问题。本工作提出了一种有效的表面洗涤方法，用含有低浓度硼酸的乙醇溶液从LiNiCoMnO材料表面去除RLCs。这是一个低成本的过程，因为过滤液可以循环利用。系统研究了洗涤时间、硼酸浓度和固液比等最佳参数。通过粉末pH值和傅里叶变换红外光谱结果确定，RLCs的量有效减少，洗涤后样品的存储性能显著提高。储存后的第150次容量保持率从原始材料的68.39%提高到洗涤后材料的85.46 - 94.84%。性能的提高应归因于表面洗涤过程，该过程不仅有效去除了RLCs，还有效去除了松散的一次颗粒。
