Wu Ziyu, Yuan Fei, Wu Siyu, Zhang Di, Wang Qiujun, Sun Qujiang, Li Zhaojin, Wang Wei, Wang Bo
Hebei Key Laboratory of Flexible Functional Materials, School of Materials Science and Engineering, Hebei University of Science and Technology, Shijiazhuang, 050000, China.
School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing, 100083, China.
Adv Sci (Weinh). 2025 Sep;12(34):e03954. doi: 10.1002/advs.202503954. Epub 2025 Jun 20.
Constructing an "ether solid electrolyte interphase (SEI)"-like layer in ester electrolyte is highly attractive to realize excellent capacity and cycling stability for hard carbon anode, but has barely been mentioned yet. Herein, the hard carbon grafted by caffeic acid is developed via a surface reconstruction strategy, in which rich C═O moieties are introduced. Varied characterizations reveal that the existing C═O exhibits stronger adsorption energy on salt (PF ) than solvent (e.g., EC and DEC), thus accelerating salt decomposition to produce a stable inorganic SEI layer. Besides, C═O moieties can also adsorb K-ions reversibly, accounting for a high capacitive contribution. Benefiting from the double merits of C═O moieties, the interfacial stability and surface properties of the optimized sample are greatly improved, and as a result, the reversible capacity can reach 462.7 mAh g (0.1 A g over 50 cycles) and rate performance is quite superior as well (321.8 mAh g at 2 A g). Besides, a prolonged cycle life of over 2000 cycles is smoothly realized at 2 A g in ester-based electrolytes. This work provides insight into the electrochemical performance improvement of ester-based electrolytes via structure design.
在酯类电解质中构建类似“醚类固体电解质界面（SEI）”的层对于实现硬碳负极优异的容量和循环稳定性极具吸引力，但目前几乎尚未被提及。在此，通过表面重构策略制备了接枝咖啡酸的硬碳，其中引入了丰富的C═O基团。各种表征表明，现有的C═O对盐（PF ）的吸附能比对溶剂（如EC和DEC）更强，从而加速盐分解以产生稳定的无机SEI层。此外，C═O基团还可以可逆地吸附K离子，这对电容有很大贡献。受益于C═O基团的双重优点，优化样品的界面稳定性和表面性质得到了极大改善，因此，可逆容量可达462.7 mAh g（在0.1 A g下循环50次），倍率性能也相当优异（在2 A g下为321.8 mAh g）。此外，在酯基电解质中，在2 A g下可顺利实现超过2000次循环的长循环寿命。这项工作为通过结构设计提高酯基电解质的电化学性能提供了思路。
