Zhao Qing, Zhang Zhibin, Song Depeng, Sun Xiaolin, Zhang Yuan, Gao Jing, Takeo Ohsaka, Futoshi Matsumoto, Wu Jianfei
Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China.
Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China.
ACS Appl Mater Interfaces. 2024 Sep 18;16(37):49227-49235. doi: 10.1021/acsami.4c06570. Epub 2024 Sep 5.
High-nickel (Ni ≥ 90%) cathodes which have a high specific capacity hold great potential for next-generation lithium-ion batteries (LIBs). However, their practical application is restricted by their high interfacial reactivity because of the presence of residual lithium (Li) compounds on the surface. Herein, the LiNiCoMnO (NCM90) cathode is surface-modified with sulfur (S) via a simple and feasible dry mixing and low-temperature heat treatment, converting the residual lithium compound on the surface into inactive lithium sulfate (LiSO). This induces the formation of a stable inorganic enriched electrode-electrolyte interface on the cathode surface and inhibits the occurrence of side reactions, ultimately inhibiting lattice collapse and the dissolution of transition metal ions. After modifying, the capacity retention rates of NCM90/Li and NCM90/graphite cells are both greatly enhanced after long cycling. This work provides a new idea for the rational design of the electrode-electrolyte interface of high-nickel cathodes.
具有高比容量的高镍（镍≥90%）阴极材料在下一代锂离子电池（LIBs）中具有巨大潜力。然而，由于表面存在残留锂（Li）化合物，其高界面反应性限制了它们的实际应用。在此，通过简单可行的干混和低温热处理，用硫（S）对LiNiCoMnO（NCM90）阴极进行表面改性，将表面的残留锂化合物转化为惰性硫酸锂（Li₂SO₄）。这在阴极表面诱导形成稳定的无机富集电极 - 电解质界面，并抑制副反应的发生，最终抑制晶格坍塌和过渡金属离子的溶解。改性后，NCM90/Li和NCM90/石墨电池在长循环后的容量保持率均大幅提高。这项工作为高镍阴极的电极 - 电解质界面的合理设计提供了新思路。
