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Electrodeposition of porous graphene networks on nickel foams as supercapacitor electrodes with high capacitance and remarkable cyclic stability.

Yang S, Deng B, Ge R, Zhang L, Wang H, Zhang Z, Zhu W, Wang G - Nanoscale Res Lett (2014)

Bottom Line: The electrodeposition process was accomplished by electrochemical reduction of graphene oxide (GO) in its aqueous suspension.The resultant binder-free PG/NF electrodes exhibited excellent double-layer capacitive performance with a high rate capability and a high specific capacitance of 183.2 mF cm(-2) at the current density of 1 mA cm(-2).Moreover, the specific capacitance maintains nearly 100% over 10,000 charge-discharge cycles, demonstrating a remarkable cyclic stability of these porous supercapacitor electrodes. 82.47.Uv (Electrochemical capacitors); 82.45.Fk (Electrodes electrochemistry); 81.05.Rm (Fabrication of porous materials).

View Article: PubMed Central - PubMed

Affiliation: Hefei National Laboratory for Physical Sciences at Microscale, and Department of Physics, University of Science and Technology of China, Hefei, Anhui, 230026, People's Republic of China, shorlin@mail.ustc.edu.cn.

ABSTRACT

Unlabelled: We describe a facile, low-cost, and green method to fabricate porous graphene networks/nickel foam (PG/NF) electrodes by electrochemical deposition of graphene sheets on nickel foams (NFs) for the application of supercapacitor electrodes. The electrodeposition process was accomplished by electrochemical reduction of graphene oxide (GO) in its aqueous suspension. The resultant binder-free PG/NF electrodes exhibited excellent double-layer capacitive performance with a high rate capability and a high specific capacitance of 183.2 mF cm(-2) at the current density of 1 mA cm(-2). Moreover, the specific capacitance maintains nearly 100% over 10,000 charge-discharge cycles, demonstrating a remarkable cyclic stability of these porous supercapacitor electrodes.

Pacs: 82.47.Uv (Electrochemical capacitors); 82.45.Fk (Electrodes electrochemistry); 81.05.Rm (Fabrication of porous materials).

No MeSH data available.


Plots of specific capacitances for PG/NFs deposited under different potentials with different times. (A) Plots of specific capacitances for PG/NF electrodes deposited under different potentials with the deposition time of 500 s versus scan rate. (B) Plots of specific capacitances versus scan rate for PG/NF electrodes deposited under constant potentials and deposition times of -1.0 V and 700 s, -1.1 V and 600 s, -1.2 V and 500 s, and -1.3 V and 400 s.
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Fig7: Plots of specific capacitances for PG/NFs deposited under different potentials with different times. (A) Plots of specific capacitances for PG/NF electrodes deposited under different potentials with the deposition time of 500 s versus scan rate. (B) Plots of specific capacitances versus scan rate for PG/NF electrodes deposited under constant potentials and deposition times of -1.0 V and 700 s, -1.1 V and 600 s, -1.2 V and 500 s, and -1.3 V and 400 s.

Mentions: We also performed a systematic investigation of the influence of deposition potential on the specific capacitance of the PG/NF electrodes. Additional file 1: Figure S2 displays the linear sweep voltammogram of nickel foam in GO deposition electrolyte scanned from 0 to -1.5 V, from which can be observed the deposition current density increase nearly linear with the decreasing potential below -0.6 V. This is because more negative deposition potential would produce stronger electric field and thereby larger deposition current. Figure 6 shows the SEM images of the PG/NFs deposited with the deposition time of 500 s under potentials of -1.0, -1.1, -1.2, and -1.3 V. As shown in the top view and cross-section SEM images, the amount of deposited graphene materials increases with more negative deposition potential. It is suggested that more negative deposition potential produced larger deposition current and resulted in more graphene sheets deposited on the NFs. However, the pores of the NF were finally blocked by excessive graphene under the deposition potential of -1.3 V, which is similar to what had happened at -1.2 V with the deposition time of 600 or 700 s. As shown in Figure 7A, the specific capacitances increased with the deposition potential from -1.0 to -1.2 V but began to decrease when the potential reached -1.3 V. The variation of the capacitance for different potentials should be attributed to the consequences of the varied deposition potential on the surface areas and accessibility to the insides of the electrodes, which is similar to that of the varied deposition time at a constant potential of -1.2 V.Figure 6


Electrodeposition of porous graphene networks on nickel foams as supercapacitor electrodes with high capacitance and remarkable cyclic stability.

Yang S, Deng B, Ge R, Zhang L, Wang H, Zhang Z, Zhu W, Wang G - Nanoscale Res Lett (2014)

Plots of specific capacitances for PG/NFs deposited under different potentials with different times. (A) Plots of specific capacitances for PG/NF electrodes deposited under different potentials with the deposition time of 500 s versus scan rate. (B) Plots of specific capacitances versus scan rate for PG/NF electrodes deposited under constant potentials and deposition times of -1.0 V and 700 s, -1.1 V and 600 s, -1.2 V and 500 s, and -1.3 V and 400 s.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4493843&req=5

Fig7: Plots of specific capacitances for PG/NFs deposited under different potentials with different times. (A) Plots of specific capacitances for PG/NF electrodes deposited under different potentials with the deposition time of 500 s versus scan rate. (B) Plots of specific capacitances versus scan rate for PG/NF electrodes deposited under constant potentials and deposition times of -1.0 V and 700 s, -1.1 V and 600 s, -1.2 V and 500 s, and -1.3 V and 400 s.
Mentions: We also performed a systematic investigation of the influence of deposition potential on the specific capacitance of the PG/NF electrodes. Additional file 1: Figure S2 displays the linear sweep voltammogram of nickel foam in GO deposition electrolyte scanned from 0 to -1.5 V, from which can be observed the deposition current density increase nearly linear with the decreasing potential below -0.6 V. This is because more negative deposition potential would produce stronger electric field and thereby larger deposition current. Figure 6 shows the SEM images of the PG/NFs deposited with the deposition time of 500 s under potentials of -1.0, -1.1, -1.2, and -1.3 V. As shown in the top view and cross-section SEM images, the amount of deposited graphene materials increases with more negative deposition potential. It is suggested that more negative deposition potential produced larger deposition current and resulted in more graphene sheets deposited on the NFs. However, the pores of the NF were finally blocked by excessive graphene under the deposition potential of -1.3 V, which is similar to what had happened at -1.2 V with the deposition time of 600 or 700 s. As shown in Figure 7A, the specific capacitances increased with the deposition potential from -1.0 to -1.2 V but began to decrease when the potential reached -1.3 V. The variation of the capacitance for different potentials should be attributed to the consequences of the varied deposition potential on the surface areas and accessibility to the insides of the electrodes, which is similar to that of the varied deposition time at a constant potential of -1.2 V.Figure 6

Bottom Line: The electrodeposition process was accomplished by electrochemical reduction of graphene oxide (GO) in its aqueous suspension.The resultant binder-free PG/NF electrodes exhibited excellent double-layer capacitive performance with a high rate capability and a high specific capacitance of 183.2 mF cm(-2) at the current density of 1 mA cm(-2).Moreover, the specific capacitance maintains nearly 100% over 10,000 charge-discharge cycles, demonstrating a remarkable cyclic stability of these porous supercapacitor electrodes. 82.47.Uv (Electrochemical capacitors); 82.45.Fk (Electrodes electrochemistry); 81.05.Rm (Fabrication of porous materials).

View Article: PubMed Central - PubMed

Affiliation: Hefei National Laboratory for Physical Sciences at Microscale, and Department of Physics, University of Science and Technology of China, Hefei, Anhui, 230026, People's Republic of China, shorlin@mail.ustc.edu.cn.

ABSTRACT

Unlabelled: We describe a facile, low-cost, and green method to fabricate porous graphene networks/nickel foam (PG/NF) electrodes by electrochemical deposition of graphene sheets on nickel foams (NFs) for the application of supercapacitor electrodes. The electrodeposition process was accomplished by electrochemical reduction of graphene oxide (GO) in its aqueous suspension. The resultant binder-free PG/NF electrodes exhibited excellent double-layer capacitive performance with a high rate capability and a high specific capacitance of 183.2 mF cm(-2) at the current density of 1 mA cm(-2). Moreover, the specific capacitance maintains nearly 100% over 10,000 charge-discharge cycles, demonstrating a remarkable cyclic stability of these porous supercapacitor electrodes.

Pacs: 82.47.Uv (Electrochemical capacitors); 82.45.Fk (Electrodes electrochemistry); 81.05.Rm (Fabrication of porous materials).

No MeSH data available.