| Full text | |
| Author(s): |
Nunes, Willian G.
[1, 2]
;
Vicentini, Rafael
[1, 2]
;
Freitas, Bruno G. A.
[1, 2]
;
Oliveira, Francisca E. R.
[1, 2]
;
Pascon Marque, Aline M.
[1, 2]
;
Maciel Filho, Rubens
[1, 2]
;
Doubek, Gustavo
[3]
;
Da Silva, Leonardo M.
[4]
;
Zanin, Hudson
[1, 2]
Total Authors: 9
|
| Affiliation: | [1] Univ Estadual Campinas, Sch Elect & Comp Engn, Carbon Sci Tech Labs, Av Albert Einstein 400, BR-13083852 Campinas, SP - Brazil
[2] Univ Estadual Campinas, Ctr Innovat New Energies, Adv Energy Storage Div, Av Albert Einstein 400, BR-13083852 Campinas, SP - Brazil
[3] Univ Campinas UNICAMP, Lab Adv Batteries, Sch Chem Engn, Adv Energy Storage Div, Ctr Innovat New Energies C, BR-13083852 Campinas, SP - Brazil
[4] Fed Univ Jequitinhonha & Mucuris Valley, Lab Fundamental & Appl Electrochem, Dept Chem, Rodovia MGT 367, Km 583, 5000, BR-39100000 Diamantina, MG - Brazil
Total Affiliations: 4
|
| Document type: | Journal article |
| Source: | JOURNAL OF ENERGY STORAGE; v. 31, OCT 2020. |
| Web of Science Citations: | 2 |
| Abstract | |
We report on the synthesis, characterization of nickel hydroxide and manganese oxide nanoparticles decorating multiwalled carbon nanotubes composite material, and electrochemical performance for energy storage pro-cesses in symmetric electrochemical capacitors. A large pseudocapacitive voltage range of 1.7 V is presented using a coin cell containing a 1.0 M Li2SO4 aqueous solution, resulting in a maximum specific capacitance of 420 F g(-1) verified at 1.67 A g(-1) during the discharge process. The symmetric coin cell was highly stable with a very high coulombic efficiency of 99% even after 70,000 cycles of charge-discharge. The high electrochemical stability of coin cell was attributed to a synergism between the nanostructured carbon support and metal (hydr) oxides nanoparticles, i.e., the transport of electrons and ions across the porous electrode structure enables with a high degree of reversibility for the solid-state redox transitions reactions, which is the main contribution to the whole electrode specific capacitance. Near-surface structural changes of the electrodes were monitored during dynamic polarization by Raman and XRD synchrotron measurements. The presence of the active Ni-O stretching mode was verified during the charge-discharge processes according to the reversible solid-state redox process. The Raman shifts were also correlated with the reversible intercalation-deintercalation processes of Li+-ions into the MnOx host material, as well as reversible adsorption of solvated ions on the surface defects of carbon nanostructures. (AU) | |
| FAPESP's process: | 16/25082-8 - Development of prototype of energy storer and supplier |
| Grantee: | Lenon Henrique da Costa |
| Support Opportunities: | Scholarships in Brazil - Master |
| FAPESP's process: | 14/02163-7 - Development of supercapacitors devices from graphene, carbon nanotubes and diamonds |
| Grantee: | Hudson Giovani Zanin |
| Support Opportunities: | Research Grants - Young Investigators Grants |
| FAPESP's process: | 17/11958-1 - CINE - Advanced Energy Storage Division |
| Grantee: | Rubens Maciel Filho |
| Support Opportunities: | Research Grants - Research Centers in Engineering Program |
| FAPESP's process: | 18/20756-6 - Pseudocapacitors from metal oxides and activated carbon composites |
| Grantee: | Willian Gonçalves Nunes |
| Support Opportunities: | Scholarships in Brazil - Doctorate |