Development Prospects and Challenges in Advancing Electrochemical Capacitor-Diodes

Electrochemical capacitor-diodes (CAPodes) are an emerging class of ion-electronic devices that merge rapid energy storage with ion rectification, enabling potential applications in low-power iontronics and biointegrated systems. Such a functionality hinges on ion-selective transport and asymmetric interfacial processes at electrodes; yet challenges persist in materials design, mechanistic clarity, and scalable integration. This perspective outlines three primary action mechanisms of CAPodes, analyzes key limitations such as kinetics and interfacial stability, and discusses strategies for advancement, including electrode material exploration, electrolyte engineering, and mechanism exploration. Furthermore, we evaluate the modularity and compatibility of CAPodes with conventional electronics, identifying pathways toward applications in logical operations, bioelectronics, and neuromorphic computing. We believe that by addressing these challenges, CAPodes could bridge ionic and electronic domains, offering opportunities for interdisciplinary innovation.