Jiao Chenyang, Zheng Qizheng, Zhang Kang, Xue Jiyuan, Liu Na, Zhang Baodan, Lin Yueli, Zhu Xuequan, Wang Changhao, Liao Hong-Gang, Shen Chong-Heng, Zou Yeguo, Qiao Yu, Sun Shi-Gang
State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, P. R. China.
Materials Innovation Department (MID), Contemporary Amperex Technology Co., Limited (CATL), Ningde 352100, P. R. China.
ACS Nano. 2025 Oct 7;19(39):35141-35153. doi: 10.1021/acsnano.5c13157. Epub 2025 Sep 22.
High-energy-density Li-rich layered oxide-based Li-metal batteries depend critically on the unique anionic redox. However, severe electrolyte decomposition and interfacial structural degradation hinder the longevity and stability of Li-rich||Li-metal batteries. Here, we show that a rational hybrid electrolyte design strategy can regulate interfacial chemistry through precise manipulation of cathode surface-exposed nucleophilic species. As a proof of concept, ethyl methyl sulfone is employed as the primary solvent due to its oxidative stability and resistance to nucleophilic attack, simultaneously strategically fabricating a fluorinated ether as a cosolvent that directs nucleophilic reaction toward its targeted functionality. Furthermore, this hybrid electrolyte design simultaneously facilitates the formation of a LiF-rich cathode electrolyte interphase (CEI) and reorganizes the solid electrolyte interphase on the Li metal from the preferential decomposition of cosolvents and anions. As a result, ultrahigh Coulombic efficiency (CE) (>99.4%) for Li-rich cathodes and enhanced Li-metal plating/stripping reversibility are achieved. Consequently, the optimized electrolyte demonstrates exceptional cycling stability, retaining 92% capacity over 100 cycles with ultrahigh average CE (>99.3%) under demanding conditions (limited Li supply, N/P = 2). Remarkably, this hybrid electrolyte enabled superior operation with anode-free cell architectures and enabled extreme temperatures (-30 to 55 °C) cycling. By effectively transforming detrimental nucleophilic attack into interfacial enhancement, this work establishes a new paradigm for electrolyte design in utilizing anionic redox chemistry.
高能量密度的富锂层状氧化物基锂金属电池严重依赖于独特的阴离子氧化还原。然而，严重的电解质分解和界面结构退化阻碍了富锂||锂金属电池的寿命和稳定性。在这里，我们表明，合理的混合电解质设计策略可以通过精确控制阴极表面暴露的亲核物种来调节界面化学。作为概念验证，乙基甲基砜因其氧化稳定性和抗亲核攻击能力而被用作主要溶剂，同时策略性地制备一种氟化醚作为共溶剂，引导亲核反应朝着其目标功能进行。此外，这种混合电解质设计同时促进了富含LiF的阴极电解质界面（CEI）的形成，并通过共溶剂和阴离子的优先分解重新组织了锂金属上的固体电解质界面。结果，实现了富锂阴极的超高库仑效率（CE）（>99.4%）和增强的锂金属电镀/剥离可逆性。因此，优化后的电解质表现出卓越的循环稳定性，在苛刻条件下（锂供应有限，N/P = 2），在100次循环中保持92%的容量，平均CE超高（>99.3%）。值得注意的是，这种混合电解质能够在无阳极电池结构中实现卓越的性能，并能够在极端温度（-30至55°C）下循环。通过有效地将有害的亲核攻击转化为界面增强，这项工作为利用阴离子氧化还原化学的电解质设计建立了一个新的范例。
