A Biocompatible Supercapacitor Diode with Enhanced Rectification Capability toward Ion/Electron‐Coupling Logic Operations

The main challenge faced by the forthcoming human–computer interaction is that biological systems and electronic devices adopt two different information carriers, i.e., ions and electrons, respectively. To bridge the gap between these two systems, developing ion/electron‐coupling devices for logic operation is a feasible and effective approach. Accordingly, herein a supercapacitor‐based ionic diode (CAPode) that takes electrochemically amorphized molybdenum oxide as the working electrode is developed. Benefiting from its unique size and charge dual ion‐sieving effects, the molybdenum oxide electrode exhibits a record‐high rectification ratio of 136, which is over 10 times higher than those of reported systems. It also delivers an ultrahigh specific capacitance of 448 F g⁻1 and an excellent cycling stability of up to 20 000 cycles, greatly outperforming those of previous works. These excellent rectification capability and electrochemical performances allow the as‐built CAPode to work well in AND and OR logic gates, validating great potential in ion/electron‐coupling logic operations. More attractively, the superior biocompatibilities of molybdenum oxide and relevant constituent materials enable the constructed CAPode to be applied as bioelectronics without regard to biosafety, paving a new way toward forthcoming human–computer interaction. A biocompatible supercapacitor diode (CAPode) is developed by employing molybdenum oxide as the working electrode. Benefiting from the size and charge dual ion‐sieving effects of molybdenum oxide electrode, the as‐built CAPode exhibits a record‐high rectification ratio that is 10 times higher than those of reported systems, which enables the constructed CAPode to work well in ion/electron‐coupling logic operation circuits.