Activated carbon coated CNT core-shell nanocomposite for supercapacitor electrode with excellent rate performance at low temperature

2019 ◽  
Vol 301 ◽  
pp. 478-486 ◽  
Author(s):  
Jiang Xu ◽  
Xi Wang ◽  
Xiaoshuang Zhou ◽  
Ningyi Yuan ◽  
Shanhai Ge ◽  
...  
2021 ◽  
Vol 59 (12) ◽  
pp. 911-920
Author(s):  
Young Mook Choi ◽  
Sang-Eun Chun

Supercapacitor electrode slurry is prepared for mass production by mixing activated carbon powder, conductive agent, and binder, which is then deposited on a substrate using the doctor-blade method. Polyvinylidene fluoride (PVDF) and 1-methyl-2-pyrrolidone (NMP) are used as binder and solvent, respectively, to form the electrode slurry on a metal substrate. In this study, ethyl cellulose (EC) is evaluated as a binder to prepare an electrode on an indium-tin-oxide (ITO) substrate obtaining transparent supercapacitors. Terpineol and isopropyl alcohol (IPA) are compared as suitable solvents for the EC binder. When terpineol is employed as a solvent, the conductive agent is uniformly deposited around the activated carbon powder. An electrode prepared using EC and terpineol exhibits slightly lower specific capacitance and rate performance than that using conventional PVDF and NMP. However, the electrode prepared using EC and terpineol securely adheres to the electrode components, resulting in a robust electrode. In contrast, an electrode prepared using EC and IPA exhibits high charge transfer resistance at the interface of the electrode/electrolyte, leading to a low specific capacitance and rate performance. Thus, ecofriendly EC and terpineol can substitute the conventional PVDF and NMP for depositing activated carbon powder on an ITO substrate, while improving the specific capacitance of manufactured electrodes.


Author(s):  
S. Edith Taylor ◽  
Patrick Echlin ◽  
May McKoon ◽  
Thomas L. Hayes

Low temperature x-ray microanalysis (LTXM) of solid biological materials has been documented for Lemna minor L. root tips. This discussion will be limited to a demonstration of LTXM for measuring relative elemental distributions of P,S,Cl and K species within whole cells of tobacco leaves.Mature Wisconsin-38 tobacco was grown in the greenhouse at the University of California, Berkeley and picked daily from the mid-stalk position (leaf #9). The tissue was excised from the right of the mid rib and rapidly frozen in liquid nitrogen slush. It was then placed into an Amray biochamber and maintained at 103K. Fracture faces of the tissue were prepared and carbon-coated in the biochamber. The prepared sample was transferred from the biochamber to the Amray 1000A SEM equipped with a cold stage to maintain low temperatures at 103K. Analyses were performed using a tungsten source with accelerating voltages of 17.5 to 20 KV and beam currents from 1-2nA.


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.


Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1672
Author(s):  
Shih-Chieh Hsu ◽  
Tzu-Ten Huang ◽  
Yen-Ju Wu ◽  
Cheng-Zhang Lu ◽  
Huei Chu Weng ◽  
...  

Carbon-coated Li4Ti5O12 (LTO) has been prepared using polyimide (PI) as a carbon source via the thermal imidization of polyamic acid (PAA) followed by a carbonization process. In this study, the PI with different structures based on pyromellitic dianhydride (PMDA), 4,4′-oxydianiline (ODA), and p-phenylenediamine (p-PDA) moieties have been synthesized. The effect of the PI structure on the electrochemical performance of the carbon-coated LTO has been investigated. The results indicate that the molecular arrangement of PI can be improved when the rigid p-PDA units are introduced into the PI backbone. The carbons derived from the p-PDA-based PI show a more regular graphite structure with fewer defects and higher conductivity. As a result, the carbon-coated LTO exhibits a better rate performance with a discharge capacity of 137.5 mAh/g at 20 C, which is almost 1.5 times larger than that of bare LTO (94.4 mAh/g).


2021 ◽  
Author(s):  
Mohd Imran ◽  
Nasser Zouli ◽  
Tansir Ahamad ◽  
Saad M. Alshehri ◽  
Mohammed Rehaan Chandan ◽  
...  

Ferrofluids prepared by dispersing superparamagnetic Fe3O4@C core–shell nanoparticles in water exhibited exceptional enhancement in thermal conductivity without an external magnetic field.


ChemInform ◽  
2006 ◽  
Vol 37 (49) ◽  
Author(s):  
Davis S. Jacob ◽  
Isaschar Genish ◽  
Lior Klein ◽  
Aharon Gedanken

2006 ◽  
Vol 110 (36) ◽  
pp. 17711-17714 ◽  
Author(s):  
David S. Jacob ◽  
Isaschar Genish ◽  
Lior Klein ◽  
Aharon Gedanken

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