The advancement of high-performance fast-charging materials has significantly propelled progress in electrochemical capacitors (ECs). Electrochemical capacitors store charges at the nanoscale electrode material–electrolyte interface, where the charge storage and transport mechanisms are mediated by factors such as nanoconfinement, local electrode structure, surface properties and non-electrostatic ion–electrode interactions. This Review offers a comprehensive exploration of probing the confined electrochemical interface using advanced characterization techniques. Unlike classical two-dimensional (2D) planar interfaces, partial desolvation and image charges play crucial roles in effective charge storage under nanoconfinement in porous materials. This Review also highlights the potential of zero charge as a key design principle driving nanoscale ion fluxes and carbon–electrolyte interactions in materials such as 2D and three-dimensional (3D) porous carbons. These considerations are crucial for developing efficient and rapid energy storage solutions for a wide range of applications.

高性能快速充电材料的进步极大地推动了电化学电容器 （EC） 的进步。电化学电容器在纳米级电极材料-电解质界面处存储电荷，其中电荷存储和传输机制由纳米限制、局部电极结构、表面特性和非静电离子-电极相互作用等因素介导。本综述全面探讨了使用先进的表征技术探测受限电化学界面。与传统的二维 （2D） 平面界面不同，部分脱溶剂和图像电荷在多孔材料纳米限域下的有效电荷存储中起着至关重要的作用。本综述还强调了零电荷作为驱动 2D 和三维 （3D） 多孔碳等材料中纳米级离子通量和碳-电解质相互作用的关键设计原则的潜力。这些考虑因素对于为各种应用开发高效、快速的储能解决方案至关重要。