Porous NiMoO<sub>4</sub>@NiMn-LDH Core–Shell Nanocomposites Anchored on Nickel Foam: Application in Asymmetric Supercapacitors with a High Specific Capacitance
Yang Yang, Yuwen Ma, Chao Sun, Chaomeng Bu, Yan Yue, Xianfu Li
Abstract
Transition-metal oxides (TMOs) exhibit exceptional potential as candidate materials in supercapacitor applications. Nevertheless, their actual performance falls far short of expectations due to challenges such as poor electronic conductivity, insufficient electrochemical durability, and the scarcity of active sites within TMOs. Herein, we successfully synthesized a NiMoO 4 nanorod@NiMn-LDH nanosheet core–shell structure onto nickel foam (NiMoO 4 @NiMn-LDH/NF) via a straightforward two-step hydrothermal process, achieving complementary enhancement in performance. The core–shell architecture effectively shortens ion transport pathways and exposes abundant active sites, which establish a vital basis for boosting the energy storage efficiency of devices. Additionally, the notable synergistic effect among transition-metal ions further boosts the electrochemical performance. Consequently, the NiMoO 4 @NiMn-LDH/NF electrode exhibits an impressive areal capacitance of 9438.4 mF cm −2 under 2 mA cm –2 . Moreover, it features pre-eminent rate capability and preserves 99.9% of its capacitance over 6000 cycles. Significantly, the constructed NiMoO 4 @NiMn-LDH/NF//activated carbon configuration achieves a 1.2 mW h cm –2 high energy density under a 3.2 mW cm –2 power density, sustaining 95% superior capacitance retention over 7000 cycles. Our research demonstrates that the NiMoO 4 @NiMn-LDH core–shell nanocomposite offers an excellent and feasible strategy for the energy storage field.