Deciphering Anion-Modulated Solvation Structure for Calcium Intercalation into Graphite for Ca-Ion Batteries

This study, for the first time, elucidates the pivotal role of anions in modulating the Ca ion solvation structures and their subsequent intercalation into graphite. Specifically, the electrostatic interactions between Ca ion and anions govern the configurations of solvated-Ca-ion in dimethylacetamide-based electrolytes and graphite intercalation compounds. Among the anions considered (BH4-, ClO4-, TFSI- and [B(hfip)4]-), the coordination of four solvent molecules per Ca ion (CN=4) leads to the highest reversible capacities and the fastest reaction kinetics in graphite. Our study illuminates the origins of the distinct Ca ion intercalation behaviors across various anion-modulated electrolytes, employing a blend of experimental and theoretical approaches. Importantly, the practical viability of graphite anodes in Ca-ion full cells is confirmed, showing significant promise for advanced energy storage systems.PMID:38606608 | DOI:10.1002/anie.202317177

Source: Angewandte Chemie - April 12, 2024 Category: Chemistry Authors: Yuyang Yi Youdong Xing Hui Wang Zhihan Zeng Zhongti Sun Renjie Li Huijun Lin Yiyuan Ma Xiangjun Pu Molly Meng-Jung Li Kyu-Young Park Zheng-Long Xu Source Type: research