Low Self‐Discharge Zn‐Ion Battery‐Type Electronic Skin for Sports Medicine Applications

ABSTRACT Flexible electronic skins (e‐skins) that integrate pressure sensing and energy storage are vital for achieving autonomous wearable systems, offering miniaturized architecture, reducing heavy wiring, and enabling static/dynamic pressure detection. However, their practical application remains restricted by severe self‐discharge behavior and limited sensing performance. Here, a self‐powered Zn‐ion battery‐type e‐skin featuring low self‐discharge is developed through the rational structural and electrochemical design. The device employs Zn‐loaded carbon‐nanotube‐modified polyurethane foam (Zn@CPUF) as the anode, a dome‐shaped zinc tetrafluoroborate (Zn(BF ₄ ) ₂ ) ionic gel electrolyte, and hot‐pressed MnO ₂ ‐loaded carbon‐nanotube‐modified polyurethane foam (MnO ₂ @CPUF‐HP) as the cathode. The dome‐shaped electrolyte ensures point contact with the electrodes in the absence of external pressure, significantly suppressing interfacial reactions and parasitic self‐discharge. Mechanical loading increases the electrode‐electrolyte contact area, reducing internal resistance and enabling high pressure sensitivity of 42.5 kPa ⁻¹ . Benefiting from the gradient‐structured electrodes, the device supports a wide detection range (1 Pa–3.23 MPa) and maintains excellent cycling stability over 10 000 compression cycles. The low self‐discharge Zn‐ion battery‐type sensor enables monitoring of physiological and motion signals and supports hand function assessment and gesture recognition, underscoring its potential for practical and low‐power wearable monitoring.