Ni(OH)₂/CNTs hierarchical spheres for a foldable all-solid-state supercapacitor with high specific energy

Abstract

Energy density and mechanical strength are crucial for practical usage of flexible supercapacitors. Herein, we demonstrate a flexible supercapacitor using Ni(OH)2/CNTs hierarchical spheres with high specific capacity (854 C g-1) and tough PBI-KOH solid polymer electrolyte. The integrated device shows high specific energy (50.6 W h kg-1) and good flexibility under folding tests.

Fabrication of Oxygen‐Vacancy Abundant NiMn‐Layered Double Hydroxides for Ultrahigh Capacity Supercapacitors

“…To the best of our knowledge, these numbers are among the bests for transition metal‐based battery‐type SC materials. As presented in Figure S3 (SI), the specific capacity of Ov‐LDH at 1 A g −1 is superior to those of the transition metal‐based materials, e.g., Co 3 O 4 /graphene (489 C g −1 ), Ni(OH) 2 /CNT (854 C g −1 ), Zn–Ni–Al–Co oxide nanosheets (839 C g −1 ), FeS 2 /graphene (793 C g −1 ), CoGa 2 O 4 microspheres (642 C g −1 ), and some other widely studied nickel‐/cobalt‐based materials, and it is also superior compared to the excellent NiAl‐LDH/nitramine‐N‐doped graphene (975 C g −1 ) . The volumetric capacity of Ov‐LDH was also calculated in Figure S4 (SI).…”

Design and fabrication of hydrotalcite-like ternary NiMgAl layered double hydroxide nanosheets as battery-type electrodes for high-performance supercapacitors

“…The Ni 2 MgAl LDH-24 h displays 45.7% retention rate when the current density changes from 1 to 3 A g-1, which is much better than 17.2% and 15.8% retention rates of Ni 2 MgAl LDH-6 h and Ni 2 MgAl LDH-12 h, respectively. However, the retention rates of these samples are slightly lower than those of reported nickel-based materials, such as Ni(OH) 2 @carbon nanosheets, 31 Ni(OH) 2 @carbon nanotubes, 32 NiO@carbon, 22 NiO. 33 The reasons could be as follows: (1) only the element of Ni 2+ in NiMgAl LDH can take part in the pseudocapacitive behavior;…”

Foldable batteries: from materials to devices

“…Transition-metal oxides are one of the most promising candidates, for pseudocapacitors, because they provide high energy density through the redox reactions occurring within the bulk material. 19,[112][113][114][115][116][117][118][119] Conductive polymers are also promising candidates. 120 However, for EDLCs, the electrical energy is stored by electrostatic accumulation on the interfacial electrolyte/electrode surface, mainly for carbon-based materials with a high specic surface area.…”