Hierarchical NiMn2O4@CNT nanocomposites for high-performance asymmetric supercapacitors

Abstract

Miniaturized energy storage devices have attracted considerable research attention due to their promising applications in various smart electronic devices. In this work, a high performance asymmetric supercapacitor (ASC) device was designed and fabricated wherein a novel nanocomposite consisting of manganese oxide (NiMn₂O₄) nanosheets with carbon nanotubes (CNTs) was used as the active material. High capacitance of 151 F g⁻¹ and energy density of 60.69 W h kg⁻¹ were achieved for the CNT@NiMn₂O₄ nanocomposites ASC at a current density of 1 A g⁻¹, which attributing to the widen operation voltage window ranging from 0 to 1.7 V. Moreover, the CNT@NiMn₂O₄ nanocomposites ASC also showed remarkable cycling stability with 96.3% energy density retention after 5000 cycles. As a result, the CNT@NiMn₂O₄ nanocomposite is a possible contender materials for next generation supercapacitors in high energy density storage systems.