Nanosheets assembled layered MXene/MoSe2 nanohybrid positive electrode materials for high-performance asymmetric supercapacitors

High-Performance Flexible Supercapacitor Device Composed of a Hierarchical 2-D MXene-Ni(OH)2 Nanocomposite and Biomass-Derived Porous Carbon Electrodes

“…The acquired XPS survey spectrum is presented in Figure S6, which shows peaks at 857.1, 683.7, 531.8, 457.6, and 285.2 eV characteristic of Ni (2p), F (1s), O (1s), Ti (2p), and C (1s) elements, respectively. The deconvoluted C 1s spectrum showed peaks at 280.5, 284.6, 285.9, and 288.9 eV because of the Ti–C, C–C, C–O, and OC–O bonds, as presented in Figure a. ,, The high-resolution XPS spectrum of Ti 2p (Figure b) consisted of four peaks at 454.1 eV (Ti–C), 457.3 (Ti–OH), 459.6, and 462.5 eV (Ti–O). ,, Figure c displays the O 1s spectrum that is deconvoluted into two peaks that can be ascribed to Ti–O/Ni–O (530.6 eV) and C–Ti–O x /Ni­(OH) 2 (532.1 eV). ,, The Ni 2p high-resolution XPS spectrum (Figure d) was deconvoluted into four constituent peaks. Two prominent peaks at 855.4 and 873.1 eV and two satellite peaks at 860.8 and 878.8 eV were attributed to Ni 2p 3/2 , Ni 2p 1/2 , and their corresponding satellite (Sat.)…”

“…This could be due to the formation of an overpotential as a result of the escalation in internal diffusion resistance at higher sweep rates. 12,35,37 The enhancement of current response with increasing scan rate indicated the fast kinetics of the electrochemical reaction, which were produced in the interface of the electrolyte and 50Mxene-50Ni(OH) 2 electrode. Randles−Sevcik plots for MXene and 50MXene-50Ni(OH) 2 are presented in Figure S13, which shows a linear increasing trend of the peak current with the progressive increment of scan rate.…”

“…4a. 36,37,41 The high-resolution XPS spectrum of Ti 2p 30,35,50 The Ni 2p high-resolution XPS spectrum (Figure 4d) was deconvoluted into four constituent peaks. Two prominent peaks at 855.4 and 873.1 eV and two satellite peaks at 860.8 and 878.8 eV were attributed to Ni 2p 3/2 , Ni 2p 1/2 , and their corresponding satellite (Sat.)…”

“…These redox peaks were due to the alternating adsorption−desorption of OH − ions and the formation of some functional groups on the surface of MXene. 35 The reversible redox reactions can be presented as (eqs 11 and 2). 41,45 Ti C (OH) OH Ti C (OH) e…”

“…These factors result in its overall decrease in EES capability and cyclability. , As an example, the C S value of pure Ti 3 C 2 T x sheets is moderately low (246 F/g) . The comparatively low C S value of MXene-based electrode materials restricts their practical applications to date. , To overcome this shortcoming, many researchers have adopted the strategy of introducing interlayer spacers within the layer structure of MXene sheets, which can adequately prevent their self-restacking and enlarge the line spacing. , This can lead to the efficient transfer of the electrolyte ions between the MXene sheets.…”