Stretchable Zn-Ion Hybrid Battery with Reconfigurable V₂CT_x and Ti₃C₂T_x MXene Electrodes as a Magnetically Actuated Soft Robot

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 V₂CT_x MXene cathodes and zinc-decorated Ti₃C₂T_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.