Synergistically engineered NiCoMn-LDH@carbon nanofibers for boosted electrochemical charge storage and high-energy supercapacitors

Abstract

Layered double hydroxides (LDHs) are emerging as advanced electrode materials for supercapacitors owing to their unique layered structures, high theoretical capacitance, and tunable metal composition. In this study, a Nickel Cobalt Manganese Layered Double Hydroxide (NiCoMn-LDH) composite with carbon nanofibers (NiCoMn-LDH@CNF) is synthesized with varying stoichiometries via a sonication-assisted method. Structural and morphological characterizations confirm the successful integration of NiCoMn-LDH with conductive CNF networks. Among the tested ratios, the 2 : 1 composition exhibits superior electrochemical performance. The enhanced behaviour of NiCoMn-LDH@CNF (2 : 1) originates from the synergistic interaction between the redox-active LDH component and the highly conductive CNF matrix, which together facilitate efficient ion diffusion and electron transport. The optimized composite demonstrates excellent conductivity and high specific capacitance during electrochemical evaluation. An asymmetric supercapacitor is further fabricated with NiCoMn-LDH@CNF as the positive electrode and activated carbon (AC) as the negative electrode. The device delivers a specific capacitance of 348 F g⁻¹ at 1 A g⁻¹, achieving an energy density of 123.8 W h kg⁻¹ at a power density of 800 W kg⁻¹. These results highlight the potential of NiCoMn-LDH@CNF as a high-performance electrode material for next-generation energy storage applications.