Structural Basis of Ultralow Capacitances at Metal–Nonaqueous Solution Interfaces

• DOI: 10.1021/jacs.4c12443
• Publication Date: 2025-01-28T03:50:51Z
• Authors: Juan Chen; Zengming Zhang; Xiaoting Yin; Chenkun Li; Fengjiao Yu; Yuping Wu; Jiawei Yan; Jun Huang; Yuhui Chen
• Keywords: Basis (linear algebra)

Metal–nonaqueous solution interfaces, a key to many electrochemical technologies, including lithium metal batteries, are much less understood than their aqueous counterparts. Herein, on several metal–nonaqueous we observe capacitances that 2 orders of magnitude lower the usual double-layer capacitance. Combining impedance spectroscopy, atomic force microscopy, and physical modeling, ascribe ultralow capacitance an interfacial layer 10–100 nm above surface. This nanometric has Young's modulus around MPa, which is softer typical solid-electrolyte interphase films. In addition, its AC ionic conductivity 4-to-5 bulk electrolyte. The temperature dependencies thickness suggest soft formed from metal-mediated, dipole–dipole interactions nonaqueous solvent molecules. observed opens new avenues modulating battery performance via rational design ion transport, (de)solvation, charge transfer in this region.