Interface Mo-N coordination bonding MoSxNy@Polyaniline for stable structured supercapacitor electrode

2021 ◽  
pp. 138953
Author(s):  
Yibing Xie ◽  
Yakui Mu
Author(s):  
Noura M. Farag ◽  
M.A. Deyab ◽  
A.M. El-naggar ◽  
A.M. Aldhafiri ◽  
Mohamed Bakr Mohamed ◽  
...  

Author(s):  
Rui Ma ◽  
Zetong Chen ◽  
Danna Zhao ◽  
Xujing Zhang ◽  
Jingting Zhuo ◽  
...  

To promote the development of supercapacitors and their applications in modern electronics, it is crucial to explore novel supercapacitor electrode materials. As a representative member of the rising 2D MXenes,...


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jeongpil Kim ◽  
Jeong-Hyun Eum ◽  
Junhyeok Kang ◽  
Ohchan Kwon ◽  
Hansung Kim ◽  
...  

AbstractHerein, we introduce a simple method to prepare hierarchical graphene with a tunable pore structure by activating graphene oxide (GO) with a two-step thermal annealing process. First, GO was treated at 600 °C by rapid thermal annealing in air, followed by subsequent thermal annealing in N2. The prepared graphene powder comprised abundant slit nanopores and micropores, showing a large specific surface area of 653.2 m2/g with a microporous surface area of 367.2 m2/g under optimized conditions. The pore structure was easily tunable by controlling the oxidation degree of GO and by the second annealing process. When the graphene powder was used as the supercapacitor electrode, a specific capacitance of 372.1 F/g was achieved at 0.5 A/g in 1 M H2SO4 electrolyte, which is a significantly enhanced value compared to that obtained using activated carbon and commercial reduced GO. The performance of the supercapacitor was highly stable, showing 103.8% retention of specific capacitance after 10,000 cycles at 10 A/g. The influence of pore structure on the supercapacitor performance was systematically investigated by varying the ratio of micro- and external surface areas of graphene.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Yibing Xie

AbstractA PPY/TiO2/PPY jacket nanotube array was fabricated by coating PPY layer on the external and internal surface of a tube wall-separated TiO2 nanotube array. It shows coaxial triple-walled nanotube structure with two PPY nanotube layers sandwiching one TiO2 nanotube layer. PPY/TiO2/PPY reveals much higher current response than TiO2. The theoretical calculation indicates PPY/TiO2/PPY reveals higher density of states and lower band gap, accordingly presenting higher conductivity and electroactivity, which is consistent with the experimental result of a higher current response. The electroactivity is highly enhanced in H2SO4 rather than Na2SO4 electrolyte due to feasible pronation process of PPY in an acidic solution. PPY/TiO2/PPY could conduct the redox reaction in H2SO4 electrolyte which involves the reversible protonation/deprotonation and HSO4− doping/dedoping process and accordingly contributes to Faradaic pseudocapacitance. The specific capacitance is highly enhanced from 1.7 mF cm−2 of TiO2 to 123.4 mF cm−2 of PPY/TiO2/PPY at 0.1 mA cm−2 in H2SO4 electrolyte. The capacitance also declines from 123.4 to 31.7 mF cm−2 when the current density increases from 0.1 to 1 mA cm−2, presenting the rate capacitance retention of 26.7% due to the semiconductivity of TiO2. A PPY/TiO2/PPY jacket nanotube with high charge storage capacitance is regarded as a promising supercapacitor electrode material.


2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Gopal Krishna Gupta ◽  
Pinky Sagar ◽  
Sumit Kumar Pandey ◽  
Monika Srivastava ◽  
A. K. Singh ◽  
...  

AbstractHerein, we demonstrate the fabrication of highly capacitive activated carbon (AC) using a bio-waste Kusha grass (Desmostachya bipinnata), by employing a chemical process followed by activation through KOH. The as-synthesized few-layered activated carbon has been confirmed through X-ray powder diffraction, transmission electron microscopy, and Raman spectroscopy techniques. The chemical environment of the as-prepared sample has been accessed through FTIR and UV–visible spectroscopy. The surface area and porosity of the as-synthesized material have been accessed through the Brunauer–Emmett–Teller method. All the electrochemical measurements have been performed through cyclic voltammetry and galvanometric charging/discharging (GCD) method, but primarily, we focus on GCD due to the accuracy of the technique. Moreover, the as-synthesized AC material shows a maximum specific capacitance as 218 F g−1 in the potential window ranging from − 0.35 to + 0.45 V. Also, the AC exhibits an excellent energy density of ~ 19.3 Wh kg−1 and power density of ~ 277.92 W kg−1, respectively, in the same operating potential window. It has also shown very good capacitance retention capability even after 5000th cycles. The fabricated supercapacitor shows a good energy density and power density, respectively, and good retention in capacitance at remarkably higher charging/discharging rates with excellent cycling stability. Henceforth, bio-waste Kusha grass-derived activated carbon (DP-AC) shows good promise and can be applied in supercapacitor applications due to its outstanding electrochemical properties. Herein, we envision that our results illustrate a simple and innovative approach to synthesize a bio-waste Kusha grass-derived activated carbon (DP-AC) as an emerging supercapacitor electrode material and widen its practical application in electrochemical energy storage fields.


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