scholarly journals Effect of Ball Milling on the Electrochemical Performance of Activated Carbon with a Very High Specific Surface Area

Batteries ◽  
2020 ◽  
Vol 6 (2) ◽  
pp. 22 ◽  
Author(s):  
Takuya Eguchi ◽  
Yugo Kanamoto ◽  
Masahiro Tomioka ◽  
Daisuke Tashima ◽  
Seiji Kumagai
Keyword(s):  
Activated Carbon ◽  
Electrochemical Performance ◽  
Specific Surface ◽  
Specific Capacitance ◽  
Ball Milling ◽  
Surface Area ◽  
Milling Time ◽  
High Specific Surface Area ◽  
Ion Transportation ◽  
Very High

Activated carbon (AC) with a very high specific surface area of >3000 m2 g−1 and a number of course particles (average size: 75 µm) was pulverized by means of planetary ball milling under different conditions to find its greatest performances as the active material of an electric double-layer capacitor (EDLC) using a nonaqueous electrolyte. The variations in textural properties and particle morphology of the AC during the ball milling were investigated. The electrochemical performance (specific capacitance, rate and cyclic stabilities, and Ragone plot, both from gravimetric and volumetric viewpoints) was also evaluated for the ACs milled with different particle size distributions. A trade-off relation between the pulverization and the porosity maintenance of the AC was observed within the limited milling time. However, prolonged milling led to a degeneration of pores within the AC and a saturation of pulverization degree. The appropriate milling time provided the AC a high volumetric specific capacitance, as well as the greatest maintenance of both the gravimetric and volumetric specific capacitance. A high volumetric energy density of 6.6 Wh L−1 was attained at the high-power density of 1 kW L−1, which was a 35% increment compared with the nonmilled AC. The electrode densification (decreased interparticle gap) and the enhanced ion-transportation within the AC pores, which were attributed to the pulverization, were responsible for those excellent performances. It was also shown that excessive milling could degrade the EDLC performances because of the lowered micro- and meso-porosity and the excessive electrode densification to restrict the ion-transportation within the pores.

Effect of Morphology of ZnCo2O4 Nanostructures on Electrochemical Performance

NANO ◽  
2016 ◽  
Vol 11 (08) ◽  
pp. 1650089 ◽  
Author(s):  
J. Y. Dong ◽  
N. Zhang ◽  
S. Y. Lin ◽  
T. T. Chen ◽  
M. Y. Zhang ◽  
...  
Keyword(s):  
Electrochemical Performance ◽  
Specific Surface ◽  
Electrochemical Properties ◽  
Specific Capacitance ◽  
Hydrothermal Method ◽  
Surface Area ◽  
Specific Surface Area ◽  
Nickel Foam ◽  
High Specific Surface Area ◽  
Active Materials

The ZnCo2O4 nanorods and nanosheets were grown on nickel foam by a facile and effective hydrothermal method, respectively. The effect of the morphologies of the nanostructures on electrochemical performance was investigated. Importantly, ZnCo2O4 nanorod electrodes with a high specific surface area exhibited a higher specific capacitance of 2457.4 F g[Formula: see text] at 2 A g[Formula: see text] and remarkable cycling stability with capacitance retention of 97.7% after 1000 cycles, which are superior to those of ZnCo2O4 nanosheet electrodes. Such a result is well explained. The investigation on the electrochemical properties of these two nanostructures as electrodes confirmed that the morphology of active materials has an important impact on electrochemical properties.

Modified polyacrylonitrile-based activated carbon fibers applied in supercapacitor

2016 ◽  
Vol 45 (3) ◽  
pp. 164-171 ◽  
Author(s):  
Linjie Su ◽  
Bohong Li ◽  
Dongyu Zhao ◽  
Chuanli Qin ◽  
Zheng Jin
Keyword(s):  
Activated Carbon ◽  
Specific Surface ◽  
Specific Capacitance ◽  
Surface Area ◽  
Specific Surface Area ◽  
Carbon Fibers ◽  
Electrode Material ◽  
High Specific Capacitance ◽  
Activated Carbon Fibers ◽  
Content Type

Purpose The purpose of this paper is to prepare a new modified activated carbon fibers (ACFs) of high specific capacitance used for electrode material of supercapacitor. Design/methodology/approach In this study, the specific capacitance of ACF was significantly increased by using the phenolic resin microspheres and melamine as modifiers to prepare modified PAN-based activated carbon fibers (MACFs) via electrospinning, pre-oxidation and carbonization. The symmetrical supercapacitor (using MACF as electrode) and hybrid supercapacitor (using MACF and activated carbon as electrodes) were tested in term of electrochemical properties by cyclic voltammetry, AC impedance and cycle stability test. Findings It was found that the specific capacitance value of the modified fibers were increased to 167 Fg-1 by adding modifiers (i.e. 20 wt.% microspheres and 15 wt.% melamine) compared to that of unmodified fibers (86.17 Fg-1). Specific capacitance of modified electrode material had little degradation over 10,000 cycles. This result can be attributed to that the modifiers embedded into the fibers changed the original morphology and enhanced the specific surface area of the fibers. Originality/value The modified ACFs in our study had high specific surface area and significantly high specific capacitance, which can be applied as efficient and environmental absorbent, and advanced electrode material of supercapacitor.

Preparation of high specific surface area and high adsorptive activated carbon by KOH activation

2019 ◽  
Vol 199 (1) ◽  
pp. 22-29 ◽  
Author(s):  
Wang-Quan Zhang ◽  
Xin Sui ◽  
Bing Yu ◽  
You-Qing Shen ◽  
Hai-Lin Cong
Keyword(s):  
Activated Carbon ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
High Specific Surface Area ◽  
Koh Activation

Frontiers of carbon materials as capacitive deionization electrodes

2020 ◽  
Vol 49 (16) ◽  
pp. 5006-5014 ◽  
Author(s):  
Yuanyuan Li ◽  
Nan Chen ◽  
Zengling Li ◽  
Huibo Shao ◽  
Liangti Qu
Keyword(s):  
Carbon Nanotubes ◽  
Activated Carbon ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Carbon Materials ◽  
High Specific Surface Area ◽  
Carbon Aerogels ◽  
Capacitive Deionization

Carbon materials are widely used as capacitive deionization (CDI) electrodes due to their high specific surface area (SSA), superior conductivity, and better stability, including activated carbon, carbon aerogels, carbon nanotubes and graphene.

scholarly journals Synthesis of a Very High Specific Surface Area Active Carbon and Its Electrical Double-Layer Capacitor Properties in Organic Electrolytes

2020 ◽  
Vol 4 (3) ◽  
pp. 43 ◽  
Author(s):  
Zheng Yue ◽  
Hamza Dunya ◽  
Maziar Ashuri ◽  
Kamil Kucuk ◽  
Shankar Aryal ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Double Layer ◽  
Specific Surface Area ◽  
Electrical Double Layer ◽  
High Specific Surface Area ◽  
Koh Activation ◽  
Electrical Double Layer Capacitor ◽  
Double Layer Capacitor ◽  
Very High

A new porous activated carbon (AC) material with very high specific surface area (3193 m2 g−1) was prepared by the carbonization of a colloidal silica-templated melamine–formaldehyde (MF) polymer composite followed by KOH-activation. Several electrical double-layer capacitor (EDLC) cells were fabricated using this AC as the electrode material. A number of organic solvent-based electrolyte formulations were examined to optimize the EDLC performance. Both high specific discharge capacitance of 130.5 F g−1 and energy density 47.9 Wh kg−1 were achieved for the initial cycling. The long-term cycling performance was also measured.

Electrosorptive Deionization Based on Activated Carbon Capacitor Prepared from Bamboo Char

2011 ◽  
Vol 233-235 ◽  
pp. 378-381
Author(s):  
Ling Zhang ◽  
Dan Zuo ◽  
Su Li Guo ◽  
Zhong Cao ◽  
Jun Liu ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Metal Ions ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Tap Water ◽  
High Specific Surface Area ◽  
Carbon Electrodes ◽  
Carbon Electrode ◽  
Direct Voltage

A kind of bamboo char with high specific surface area has been studied as the absorption material of the activated carbon electrodes, and the electrosorptive deionization ability of the as-obtained electrodes for elimination of metal ions in tap water has been examined under certain direct voltage. The effects of the distance between the elect rode plates, and the numbers of the electrode plates have been investigated in detail. The results show that the electrodes exhibit the optimal deionization ability over 2 cm of distance between the electrode plates and 4 couples of the elect rode plates. The reverse wash treatment indicates that the activated carbon electrodes can be cycle used. The efficiency order of the electrosorptive deionization of different metal ions on the activated carbon electrode has been summarized as follows: Pb2+＞Cu2+＞Cr3+＞Cd2+.

scholarly journals Synthesis of Honeycomb-like Co3O4 Nanosheets with Excellent Supercapacitive Performance by morphological controlling derived from the alkaline source ratio

2018 ◽  
Author(s):  
Wanli Jia ◽  
Jun Li ◽  
Zhongjie Lu ◽  
Yongfei Juan ◽  
Yunqiang Jiang
Keyword(s):  
Electrochemical Performance ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Morphological Evolution ◽  
High Specific Surface Area ◽  
Galvanostatic Charge ◽  
X Ray ◽  
Charge Discharge ◽  
Discharge Test

Honeycomb-like CO3O4 nanosheets with high specific surface area were successfully synthesized on porous nickel foam by the facile hydrothermal method followed by an annealing treatment (300 °C), which were used as high-performance supercapacitor electrodes. The effects of mole ratio of hexamethylenetetramine (HMT) and Co(NO3)2 (1:1, 2:1, 3:1, 4:1, 5:1 and 6:1）as the reactants on morphological evolution and electrochemical performance of the electrodes were investigated in detail. X-ray diffractometry, transmission electron microscopy, X-ray photoelectron spectroscopy and scanning electron microscopy were applied to characterize the structure and morphology of the products. The electrochemical performance was measured by cyclic voltammetry (CV) and galvanostatic charge/discharge. The results indicated that phase constituents were almost unaffected with the change in mole ratio of HMT and Co(NO3)2. However, the significant morphological evolution of Co3O4 was observed with increasing the mole ratio, which was described as followed: the nanosheets accompanied with a large number of spherical nanoparticles→the formation of some strip-like particles due to the agglomeration of spherical nanoparticles→the formation of new nanosheets resulting from the growth of strip-like particles→the formation of coarse flower-like particles owing to the connection among the nanosheets→the nanosheets gradually covered with flower-like particles. Accompanied with the change, the specific surface area was increased firstly, and then decreased. A maximum was obtained in the HMT and Co(NO3)2 mole ratio of 4:1, which was further validated by CV and galvanostatic charge/discharge tests. The specific capacitance value was 743.00 F·g-1 at 1 A·g-1 in the galvanostatic charge/discharge test, which was apparently higher than those in the other mole ratios (139.11 F·g-1 in 1:1, 280.46 F·g-1 in 2:1, 503.29 F·g-1 in 3:1, 463.75 F·g-1 in 5:1 and 363.74 F·g-1 in 6:1). The change was also observed in the CV test with a scanning rate of 5 mV·s-1 (121.32 F·g-1 in 1:1, 217.33 F·g-1 in 2:1, 559.86 F·g-1 in 3:1, 693.56 F·g-1 in 4:1, 423.35 F·g-1 in 5:1 and 321.64 F·g-1 in 6:1). Co3O4 synthesized in the mole ratio of 4:1 also demonstrated an excellent cyclic performance, in which about 97% of the initial specific capacitance was remained at 1 A·g-1 for 500 cycles in the galvanostatic charge/discharge test. This excellent electrochemical performance was ascribed to high specific surface area of Co3O4 nanosheets that provide enough channels and space for ions transportion.

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