ZnMoO4/MoO3 composite materials via facile one-step hydrothermal route for efficient hybrid supercapacitors

Engineering novel transition metal oxide materials with two-dimensional nano/microarchitectures has demonstrated significant electrochemical properties in the energy storage field because of their particular morphological structures and conductive metal ions. In this report, mixed microstructured-based zinc molybdenum oxide/molybdenum oxide (ZnMoO4/MoO3 (ZMO/MO)) composite materials were prepared via a hydrothermal synthesis procedure at the temperatures of 120, 160, and 200 °C. Furthermore, the effects of temperature on the morphological, structural, and surface area properties of the synthesized ZMO/MO samples were investigated. The optimized ZMO/MO-160 material (synthesized at 160 °C) exhibited superior electrochemical performance compared to the other materials. The ZMO/MO-160 electrode delivered high specific capacity/capacitance values of 226 mAh g−1/1594 F g−1 at a current density of 1 A g−1. Moreover, the ZMO/MO-160 electrode revealed decent cycling stability with a capacity retention of 81.6 % and excellent coulombic efficiency (CE) of 100 % after 20,000 cycles. More importantly, a pouch-type hybrid supercapacitor (HSC) was fabricated (ZMO/MO-160//activated carbon), exhibiting maximum energy and power density values of 25.65 Wh kg−1 and 2914.77 W kg−1, respectively. The prepared HSC revealed excellent cycling stability with 81 % capacity retention and 99 % CE after 30,000 cycles. Finally, the practical application of the equipped HSCs was verified by powering various electronic gadgets, suggesting the real-time applicability of HSCs in energy storage fields.