Cathode‐Free Aqueous Micro‐battery for an All‐in‐One Wearable System with Ultralong Stability

Abstract Constructing an all‐in‐one wearable electronic system integrated with an energy‐harvesting, an energy‐storing, and a working unit can fundamentally solve the problems of sustainable energy supply, miniaturization, and lightweight for further commercialization. Here, an all‐in‐one wearable system consisting of solar cell, cathode‐free zinc ion micro‐battery (ZIMB) and piezoresistive pressure sensor is proposed, achieving an ultralong and stable power supply. Under the action of photocurrent, this integrated system is stimulated to in situ generate MnO 2 on the initial cathode‐free substrate, meanwhile converts into chemical energy for powering the sensor, which eliminates prepreparation and treatment of the cathode for energy storage units. The facial cathode‐free ZIMB combining the all‐in‐one design enhances matching degree between different units and improves the integration. The working mechanism of the cathode‐free ZIMB is analyzed systematically through multiple ex situ characterizations and density functional theory (DFT) simulation. And the integrated sensing system illuminating for 12.0 h realizes the ultralong energy supply of the pressure sensor up to 150 000 cycles. As a concept, the integrated wearable electronic is used to detect human physiological signals, showcasing potential applications in activity monitoring, intelligent robotics, human–computer interaction, and other related fields.