Zhang Xin, Wu Tao, Jian Jiyuan, Lin Shuang, Sun Dandan, Fu Gang, Xu Yan, Liu Ziwei, Li Sai, Huo Hua, Ma Yulin, Yin Geping, Zuo Pengjian, Cheng Xinqun, Du Chunyu
State Key Laboratory of Space Power-Sources, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, 150001, P. R. China.
Zibo Torch Energy Co., Ltd., 19 Nanluo Road, Zhangdian District, Zibo, Shandong, 255051, P. R. China.
Small. 2024 Nov;20(45):e2404488. doi: 10.1002/smll.202404488. Epub 2024 Jul 29.
A great challenge in the commercialization process of layered Ni-rich cathode material LiNiCoMnO (NCM, x ≥ 80%) for lithium-ion batteries is the surface instability, which is exacerbated by the increase in nickel content. The high surface alkalinity and unavoidable cathode/electrolyte interface side reactions result in significant decrease for the capacity of NCM material. Surface coating and doping are common and effective ways to improve the electrochemical performance of Ni-rich cathode material. In this study, an in situ reaction is induced on the surface of secondary particles of NCM material to construct a stable lithium sulfate coating, while achieving sulfur doping in the near surface region. The synergistic modification of lithium sulfate coating and lattice sulfur doping significantly reduced the content of harmful residual lithium compounds (RLCs) on the surface of NCM material, suppressed the side reactions between the cathode material surface and electrolyte and the degradation of surface structure of the NCM material, effectively improved the rate capability and cycling stability of the NCM material.
用于锂离子电池的层状富镍正极材料LiNiCoMnO（NCM，x≥80%）商业化过程中的一个巨大挑战是表面不稳定性，而镍含量的增加会加剧这种不稳定性。高表面碱度以及不可避免的正极/电解质界面副反应导致NCM材料的容量显著下降。表面包覆和掺杂是提高富镍正极材料电化学性能的常见且有效的方法。在本研究中，在NCM材料二次颗粒表面引发原位反应，以构建稳定的硫酸锂包覆层，同时在近表面区域实现硫掺杂。硫酸锂包覆和晶格硫掺杂的协同改性显著降低了NCM材料表面有害残留锂化合物（RLC）的含量，抑制了正极材料表面与电解质之间的副反应以及NCM材料表面结构的降解，有效提高了NCM材料的倍率性能和循环稳定性。
