posted on 2024-01-30, 10:43authored byJunjun Hu, Zhenhua Wu, Zhenying Sun, Shengshang Lu, Tong Guo, Wensheng Yang, Quan Xie, Yunjun Ruan
Transition-metal
double hydroxides offer many benefits, including
abundant nanostructures, low cost, easy preparation, diverse compositions,
and adjustable physicochemical properties, which have a wide range
of applications and are highly promising for the development of high-performance
electrode materials. Herein, hydrangea-like manganese-doped nickel–cobalt
double hydroxide (NiCoDH-Mn) nanostructures were prepared through
a fast one-step microwave hydrothermal method within a few minutes.
A thorough analysis was conducted on how the nanostructure, crystal
structure, and electrochemical properties of the samples were affected
by the amount of the Mn doping content. Density functional theory
(DFT) calculations demonstrated that the introduction of Mn doping
can generate impurity levels around the Fermi level of NiCoDH, enhancing
its electrical conductivity. At a current density of 1 A g–1, the optimized NiCoDH-Mn has a remarkable specific capacity of 107.4
mA h g–1. Even when the current density increases
by 15 times, it can still maintain a high specific capacity of 66.3
mA h g–1. After undergoing 1500 cycles with a current
density of 5 A g–1, the electrode’s capacity
remains 128%. The hybrid supercapacitor consisting of the NiCoDH-Mn
cathode and mango seed-derived activated carbon anode has an impressive
energy density of 47.9 W h kg–1 and a power density
of 850 W kg–1. Moreover, it boasts an impressive
capacitance retention rate of 87.5%, even after 5000 cycles. We offer
a highly effective and speedy approach to creating high-performance
transition-metal hydroxides that are ideal for energy storage systems.