Zinc Manganite as an Efficient Battery-grade Material for Supercapattery Devices

Abstract In the current context, supercapatteries emerge as highly desirable candidates capable of merging both energy and power density within a single device. Battery-type metal oxide materials, combined with capacitive-based materials, stand out as promising candidates for high-performance supercapatteries. This investigation centers on the synthesis of nanocrystalline ZnMn2O4 (ZMO) and CoMn2O4 (CMO) through a straightforward hydrothermal method, followed by their physico-electrochemical characterization. Electrochemical analysis reveals that ZMO exhibits notably enhanced charge storage capability compared to CMO. This superiority can be attributed to favourable electro-structural properties, and stable redox chemistry of ZMO. The real-time performance of ZnMn2O4 was further assessed by fabricating a hybrid asymmetric supercapattery device (ZnMn2O4||NrGO), which achieves a specific capacity of 232 C g− 1 at a current density of 1 A g− 1. The hybrid asymmetric device underwent rigorous stability testing for 4000 cycles at a current density of 2 A g− 1, showcasing remarkable performance with a 92% retention of its initial capacity. The device demonstrated a power density of 10 kW kg− 1 and an energy density of 22 W h kg− 1, highlighting its considerable promise in the field.