“Faraday Cage” Induced Anion-Confined Interface Enables Industrially Compatible Microsized Silicon Anodes
Ziyun Zhao, Jingshuo Zhang, Jiawei Shi, Fanqi Chen, Yong Guo, Siyuan Pan, Yingxin Liu, Xiangze Xin, Yun Tian, Zhen Zhou, Shichao Wu, Zhe Weng, Quan‐Hong Yang
Abstract
The anion-derived inorganic-rich solid electrolyte interphase (SEI) provides highly desirable protection for anodes; however, it is hardly formed in commercial electrolytes due to the electromigration of free anions away from anodes under the charging electric field. High-concentration electrolytes are capable of curing this issue, but they are economically impractical. Here, we pioneer an industrially compatible approach to shield the electric field by engineering a surface “Faraday cage” from a polymer matrix electrostatically integrated with a weakly dissociated salt. An anion-confined interphase (ACI) is produced on the representative silicon microparticles (SiMPs). The ACI enables a sustainable anion-enriched microenvironment, which promotes the participation of anions in the Li + solvation sheath and guarantees more anion reduction to the inorganic-rich SEI upon long cycling stability at a high areal capacity (∼4 mAh cm –2 ). This approach offers a straightforward yet practical solution to SEI innovation in commercial batteries.