Stretchable Zn‐Ion Hybrid Battery with Reconfigurable V2CTx and Ti3C2Tx MXene Electrodes as a Magnetically Actuated Soft Robot

Abstract Stretchable energy storage devices have become indispensable components toward energy autonomy for wearable electronic, implantable medical devices, and untethered soft machines. A Zn‐based battery with a neutral electrolyte could act as a competitive candidate for wearable/implantable electronics because of its intrinsic safety and high energy density. Therefore, it is highly desired to develop a synergistic combination of stretchable anodes/cathodes and neutral electrolytes for stretchable Zn‐based batteries. Herein, a scalable fabrication process is developed to produce stretchable Zn‐ion hybrid batteries composed of V 2 CT x MXene cathodes and zinc‐decorated Ti 3 C 2 T x MXene anodes. To endow high stretchability to the Zn‐ion hybrid battery, both MXene‐based electrodes are fabricated with crumple‐like microtextures enabling reversible folding/unfolding behaviors to attenuate in‐plane stress while stretching. In comparison with the state‐of‐the‐art work, the as‐fabricated Zn‐ion hybrid battery features large deformability (50% strain), ultrathin device (≈170 µm), low areal weight (≈20 mg cm −2 ), and an ultralow self‐discharge rate (0.7 mV h −1 ), and demonstrates rechargeable and strain‐insensitive specific capacities of 118.5 and 103.6 mAh g −1 under 0% and 50% strains, respectively. Finally, with ultrathin and lightweight merits, the stretchable battery is further fabricated into a magnetically actuated soft robot with remote control, capable of crawling between two designated points for charging/discharging tasks.