Dynamic Imine Chemistry Enables Paintable Biogel Electrolytes to Shield On-Body Zinc-Ion Batteries from Interfacial Interference

On-body batteries with hydrogel electrolytes are a pivotal enabling technology to drive bioelectronics for healthcare and sports, yet they are prone to failure due to dynamic interfacial interference, accompanied by e-waste production. Here, dynamic imine chemistry is proposed to design on-electrode paintable biogel electrolytes that feature temperature-controlled reversible phase transition (gelling within 1.5 min) and ultrafast self-healing capability (6 s), establishing a dynamically self-adaptive interface on cyclically deforming electrodes for shielding on-body Zn-ion batteries from interfacial interference. Consequently, the deformed Zn anode shows an exceptional cycling stability of 400 h regardless of the bending radius, and the as-assembled Zn–I2 battery delivers sufficient durability to endure 5000 deformation cycles, together extending to 1300 h and 15 000 deformation cycles via dynamically restarting the interfacial electric field, respectively. Also, the features of recyclability, biodegradation, and biocompatibility make the proposed on-body Zn–I2 batteries appealing in terms of sustainability and biosafety, enabling their successful power supply of heart rate monitors in sports. This work demonstrates the promise of dynamic biogel chemistry for green and biorelated energy-storage systems.