V ₂ CT _x //MnO ₂ Based Zinc‐Ion Hybrid Micro‐Supercapacitors with High Energy Density for Wearable Electronic Devices

Abstract The increasing demand for portable electronic devices has significantly advanced the energy storage sector. In recent years, aqueous zinc‐ion hybrid micro‐supercapacitor (ZIHMSC) has emerged as a focal point of research due to their superior power density, enhanced safety and reduced cost. This work introduces a flexible ZIHMSC featuring MnO ₂ cathode and V ₂ CT _x anode. The optimal charge balance and work function difference between V ₂ CT _x and MnO ₂ electrodes, significantly increase an admirable energy density of 150 µWh cm ⁻² at the power density of 470 µW cm ⁻² and achieve 1.9 V wide voltage window. Moreover, the device also demonstrates areal capacitance with 306 mF cm ⁻² . The working mechanism is analyzed by density functional theory (DFT) calculations and using various in situ and ex situ characterization test methods. The V ₂ CT _x //MnO ₂ based ZIHMSC can be integrated into the sensing system, and effectively detect various human activities, highlighting its application value for wearable electronic technology. This work offers an innovative approach for developing next generation zinc‐ion hybrid device owing high energy density.