Hierarchical core–shell 2D MOF nanosheet hybrid arrays for high-performance hybrid supercapacitors

Abstract

Two-dimensional (2D) metal-organic frameworks (MOFs) with large surface area, ordered pores and ultrathin thickness have recently emerged as ideal electrode materials for supercapacitors (SCs). However, their straightforward applications are restricted...

NiO/Ni Metal–Organic Framework Nanostructures for Asymmetric Supercapacitors

“…The specific capacity ( C s , mA h g –1 ) and specific capacitance ( C sp , F g –1 ) were calculated via formulas and where I (A), Δ t (s), m (g), and Δ V (V) are the discharge current, discharge time, mass of the active material, and potential window of the charging/discharging process, respectively.…”

“…The supercapacitor performances of the NiO/Ni-MOF-25 electrode and other relevant reported electrodes are compared in Table 2. Compared with Ni-MOF-based materials directly deposited on nickel foam, 25,27 the NiO/Ni-MOF-25 electrode had a lower specific capacitance mainly resulting from the existence of the additives and binders in the electrode fabrication. As we know, the direct NF substrate could afford a good electrical conductivity, while additives and binders could lead to "dead volume" and difficult diffusion of electrolyte ions into the bulk electrode that inevitably resulted in a relatively poor electrochemical performance.…”

“…The energy density ( E ) and power density ( P ) of the ACS device were obtained via the following eqs and : where C sp is the specific capacitance of the device obtained from the discharge curves on the basis of the gross quality of the active negative and positive materials. E (W h kg –1 ), P (W kg –1 ), Δ t (s), and Δ V (V) are correspondingly the energy density, power density, discharge time of the device, and working voltage window.…”

Recent progress of battery grade metal sulfides for hybrid energy storage devices

“…Therefore, on providing connection to electrodes, almost equal amount of reactants and products enter and leave the electrode surface, which illustrate that amount of charges transfer into the electrode gets out of it at the same rate without being stored 13 . Active materials that have mostly utilized for SBs include metal hydroxides (Ni(OH) 2 , Co(OH) 2 ), metal oxides (Co 3 O 4 , V 2 O 5 , NiO, MnO 2 ) and metal phosphates such as Ag 3 (PO 4 ), Mn 3 (PO 4 ) 2 , and Ni 3 (PO 4 ) 2 respectively 14‐21 . However, by virtue of redox active sites SBs reveal tremendous electrochemical results and hence display great values of specific energies and rate capabilities.…”

“…13 Active materials that have mostly utilized for SBs include metal hydroxides (Ni (OH) 2 , Co(OH) 2 ), metal oxides (Co 3 O 4 , V 2 O 5 , NiO, MnO 2 ) and metal phosphates such as Ag 3 (PO 4 ), Mn 3 (PO 4 ) 2 , and Ni 3 (PO 4 ) 2 respectively. [14][15][16][17][18][19][20][21] However, by virtue of redox active sites SBs reveal tremendous electrochemical results and hence display great values of specific energies and rate capabilities. Moreover, fast Faradic reactions in SBs reduces its specific power and potential stability which bound its wide exercises and large-scale industrial applications.…”