Enhanced performance of asymmetric supercapacitor based on NiZn-LDH@NiCoSe₂ electrode materials

Abstract

While supercapacitors have been widely studied as the next generation of energy storage devices, to develop active electrode materials for enhancing device performance is still challenging. Herein, we fabricated asymmetric supercapacitors based on NiZn-Layered double hydroxide (LDH) @NiCoSe2 hierarchical nanostructures as electrode materials. The NiZn-LDH@NiCoSe2 composites are deposited on Ni foam by a two-step strategy, in which NiZn-LDH nanosheets were firstly grown on Ni foam by hydrothermal method, and then NiCoSe2 particles were prepared by electrodeposition. Due to the synergistic effect between NiZn-LDH and NiCoSe2, excellent device performance was achieved. In a three-electrode system, the NiZn-LDH@NiCoSe2 exhibits a specific capacitance of 2980 F g-1 at 1 A g-1. Furthermore, the asymmetric supercapacitor of NiZn-LDH@NiCoSe2//activated carbon (AC) device was assembled, which exhibits the energy density of 49.2 Wh kg−1 at the power density of 160 W kg−1, with the capacity retention rate is 91% after 8000 cycles. The results indicates that NiZn-LDH@NiCoSe2 is a promising candidate as electrode materials for efficient energy storage devices.

Synergistically Driven CoCr-LDH@VNiS2 as a Bifunctional Electrocatalyst for Overall Water Splitting and Flexible Supercapacitors

“…The energy density and power density are the most important parameters to evaluate the performance of the ASC device. 29,30 Figure 7h indicates the Ragone plots demonstrate the maximum energy density of 96.03 W h kg −1 at a power density of 539.98 W kg −1 , which is superior compared to the previously reported ASC devices such as CoO@CoAl-LDH, 31 CoNi LDH/MnOX, 32 NiCoP@NiFe-LDH, 33 NiZn-LDH@ NiCoSe 2 , 34 Co-NiS/NCDs, 35 and Co-MOF@CoCr 2 O 4 . 36 The long-term cyclic stability of the CoCr-LDH@VNiS 2 ASC device is illustrated in Figure 7i.…”

Facile Fabrication of Iron Cobalt Sulfide Nanoparticles within N-Doped Graphene for High-Performance Supercapacitors

“…The assembled ASC device achieves an extraordinary energy density of 79.3 Wh kg –1 at a power density of 804 W kg –1 . Even at a high power density of 15,069 W kg –1 , the energy density of the ASC device still keeps 47.3 W h kg –1 , which is predominant in comparison with the previously reported ASCs, such as CCSe-HSs//AC (53.86 W h kg –1 at 800 W kg –1 ), (NiOH) 2 /rGO//AC (39.64 W h kg –1 at 1962 W kg –1 ), NiZn-LDH@NiCoSe 2 //AC (49 W h kg –1 at 160 W kg –1 ), NiO/CeO 2 //Bi-Ni-O (78 W h kg –1 at 201 W kg –1 ), CNTs/K x MnO 2 //Ti 3 C 2 T x /MoO 3 (36.4 W h kg –1 at 863 W kg –1 ), and NiCoFe-LDH/Ti 3 C 2 //rGO (54.4 W h kg –1 at 895 W kg –1 ) …”

“…Strong redox peaks in CV curves of FeCoS 2 /NG are observed, indicating that the capacitive property is governed by the faradic redox process. The electrochemical behavior of FeCoS 2 /NG is proposed as follows: FeS 2 + OH − ⇌ Fe normalS 2 OH + normale − CoS 2 + OH − ⇌ Co normalS 2 OH + normale − Fe normalS 2 OH + OH − ⇌ Fe normalS 2 normalO + normalH 2 normalO + normale − Co normalS 2 OH + OH − ⇌ Co normalS 2 normalO + normalH 2 normalO + normale − …”

“…Strong redox peaks in CV curves of FeCoS 2 /NG are observed, indicating that the capacitive property is governed by the faradic redox process. The electrochemical behavior of FeCoS 2 /NG is proposed as follows: …”

Oxygen vacancies of NiMoO4 nanoneedles on Ni foam for high-performance asymmetric supercapacitors

“…[5][6][7] Among them, supercapacitors have received extensive attention from researchers due to their high power density and fast charging and discharging capabilities. [8][9][10] However, the lower energy density of supercapacitors is an important factor hindering their further development. Therefore, researchers have used various methods to increase the energy density of supercapacitors.…”