Liu Yubin, Deng Jiaqi, Tan Sijing, Ou Xun, Luo Junfeng, Fang Jiaxu, Zhao Zaowen, Chen Chi-Liang, Zeng Ronghua, Zhang Xiaoyang, Li Hong, Zhang Jiliang, Zhao Ruirui
School of Chemistry, Guangdong Provincial International Joint Research Centre for Energy Storage Materials, Engineering Research Centre of MTEES (Ministry of Education), South China Normal University, Guangzhou 510006, PR China.
State Key Laboratory of Tropic Ocean Engineering Materials and Materials Evaluation, School of Materials Science and Engineering, Hainan University, Haikou 570228, PR China.
J Colloid Interface Sci. 2025 Dec;699(Pt 2):138172. doi: 10.1016/j.jcis.2025.138172. Epub 2025 Jun 14.
The cathode-electrolyte interphase (CEI) is vital in lithium ion batteries as its electron/ion transfer efficiency at the electrode-electrolyte boundary governs the overall reaction kinetics. However, the dynamic nature of the CEI during cycling compromises electrochemical stability, resulting in rapid capacity degradation. Herein, we propose a facile in-situ strategy to engineer a thin and robust CEI layer on LiCoO (LCO) cathodes by making use of charge modulation between Co and Mn. The passivization of reactive Co sites at the surface effectively suppresses the continuous electrolyte decomposition and Co dissolution, subsequently mitigating surface structural phase distortion. Concurrently, the inhibited phase distortion stabilized the interfacial electric field, promoting the formation of a dynamically mechanically stable CEI with enhanced ionic conductivity. The modified LCO cathode achieves much better cycling stability, alongside improved rate capability. This work elucidates the critical interplay between charge modulation and CEI dynamics, offering a universally adaptable approach for designing high-performance layered oxide cathodes in metal-ion batteries.
阴极-电解质界面（CEI）在锂离子电池中至关重要，因为其在电极-电解质界面处的电子/离子转移效率决定了整体反应动力学。然而，循环过程中CEI的动态性质会损害电化学稳定性，导致容量迅速下降。在此，我们提出了一种简便的原位策略，通过利用Co和Mn之间的电荷调制，在LiCoO（LCO）阴极上构建一层薄而坚固的CEI层。表面活性Co位点的钝化有效地抑制了电解质的持续分解和Co的溶解，随后减轻了表面结构相畸变。同时，受抑制的相畸变稳定了界面电场，促进了具有增强离子导电性的动态机械稳定CEI的形成。改性后的LCO阴极实现了更好的循环稳定性以及更高的倍率性能。这项工作阐明了电荷调制与CEI动力学之间的关键相互作用，为设计金属离子电池中的高性能层状氧化物阴极提供了一种普遍适用的方法。
