Interlayer Confined Capacitive Response via Solvated Cointercalation in Graphite Layers

作者：Xiaojuan Huang, Yifan Cheng, Huan Liu, Xiaoqing Chang, Guiyang Gao, Zerui Yan, Qianqian Wu, Yunpeng Zhong, Gen Chen, Zhangquan Peng, Dong‐Liang Peng, Jinhui Chen, Guiming Zhong, Qiulong Wei · 发表于：ACS Nano · 年份：2025 · DOI：10.1021/acsnano.4c16593 · 被引用次数：12 · 研究领域：Advancements in Battery Materials、Supercapacitor Materials and Fabrication、Graphene research and applications

Nanofluids confined within two-dimensional materials promote ionic flux, which is essential for achieving ultrahigh-rate capacitor-like responses and high charge storage capacity. Here, we offer quantitative and microscopic insights into the interlayer-confined electric double-layer (EDL) capacitive behavior arising from the cointercalation of Na + - x diglyme ([Na- x G2] + ) into graphite layers. By leveraging in situ nuclear magnetic resonance, electrochemical quartz crystal microbalance, embedded optical fiber sensors, and other techniques, it demonstrates that a nonconstant Na +:G2 ratio during cointercalation into graphite with the evolution of the stages. This aligns with the formation of graphite intercalation compounds (GICs) from stage >3 to 1, and a subsequent transition from battery-like intercalation to interlayer-confined EDL adsorption. The stage 1 GIC with an expanded spacing of 1.168 nm shows confined solvated Na + ions with strong interactions with carbon, which features the formation of highly mobile Na + ions and G2 solvents, leading to the high-rate and stable performance. Our findings offer a deep understanding of the preconditions and microstructure necessary for confined solvated ions in layered materials with capacitor-like electrochemical behavior.