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Fabrication of thickness controllable free-standing sandwich-structured hybrid carbon film for high-rate and high-power supercapacitor.

Wei H, Wei S, Tian W, Zhu D, Liu Y, Yuan L, Li X - Sci Rep (2014)

Bottom Line: Here we demonstrate a simple approach to fabricate free-standing sandwich-structured hybrid carbon film composed of porous amorphous carbon film and multilayer graphene film by chemical vapor deposition in a controllable and scalable way.Supercapacitors assembled by hybrid carbon films exhibit ultrahigh rate capability, wide frequency range, good capacitance performance, and high-power density.Moreover, this approach may provide a general path for fabrication of hybrid carbon materials with different structures by using different metals with high carbon solubility, and greatly expands the application scope of carbon materials.

View Article: PubMed Central - PubMed

Affiliation: School of Physics, Huazhong University of Science and Technology, Wuhan, Hubei. 430074, PR China.

ABSTRACT
Hybrid carbon films composed of graphene film and porous carbon film may give full play to the advantages of both carbon materials, and have great potential for application in energy storage and conversion devices. Unfortunately, there are very few reports on fabrication of hybrid carbon films. Here we demonstrate a simple approach to fabricate free-standing sandwich-structured hybrid carbon film composed of porous amorphous carbon film and multilayer graphene film by chemical vapor deposition in a controllable and scalable way. Hybrid carbon films reveal good electrical conductivity, excellent flexibility, and good compatibility with substrate. Supercapacitors assembled by hybrid carbon films exhibit ultrahigh rate capability, wide frequency range, good capacitance performance, and high-power density. Moreover, this approach may provide a general path for fabrication of hybrid carbon materials with different structures by using different metals with high carbon solubility, and greatly expands the application scope of carbon materials.

No MeSH data available.


Design of free-standing carbon films.Schematic illustration of the fabrication process of HCF and PACF, (a) decomposition of methane, carbon atom adsorption, diffusion and dissolution at growth temperature, (b) graphene growing and a large number of carbon atoms dissolving in Ni foil, (c) part of the carbon atoms segregating/precipitating on Ni surface to form MGF, and another part of the carbon atoms trapped in Ni foil, (d) MGFs detaching from both sides of the Ni foil in ferric chloride solution, (e) free-standing HCF after Ni foil completely etched, (f) etching Ni foil in ferric chloride solution after the removal of MGFs, (g) and (h) etching Ni foil and formation of the PACF, (i) free-standing PACF after Ni foil completely etched.
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f1: Design of free-standing carbon films.Schematic illustration of the fabrication process of HCF and PACF, (a) decomposition of methane, carbon atom adsorption, diffusion and dissolution at growth temperature, (b) graphene growing and a large number of carbon atoms dissolving in Ni foil, (c) part of the carbon atoms segregating/precipitating on Ni surface to form MGF, and another part of the carbon atoms trapped in Ni foil, (d) MGFs detaching from both sides of the Ni foil in ferric chloride solution, (e) free-standing HCF after Ni foil completely etched, (f) etching Ni foil in ferric chloride solution after the removal of MGFs, (g) and (h) etching Ni foil and formation of the PACF, (i) free-standing PACF after Ni foil completely etched.

Mentions: Figure 1 illustrates a schematic representation of the fabrication process of free-standing HCF. After methane decomposition at growth temperature, carbon atoms adsorb on Ni surface, and then diffuse and dissolve in Ni foil (Figure 1a). Over time, a large number of carbon atoms dissolve in Ni foil because of higher carbon solubility and diffusivity of the Ni metal28293031, and graphene grows on Ni surface at the same time (Figure 1b). It is generally believed that the dissolved carbon atoms segregate/precipitate on Ni surface to form MGF during rapid cooling process28293031. However, it should be noted that this segregation/precipitation process may be limited by: (1) rapidly cooling which may result in a quench effect in which the dissolved carbon atoms lose the mobility232831; and (2) high work pressure and high concentration of carbon atom which may hinder the segregation/precipitation of the dissolved carbon atoms during APCVD process. As a result, only part of the dissolved carbon atoms can segregate/precipitate on the Ni surface to form MGF, and a large number of carbon atoms will be trapped in Ni foil (Figure 1c). After APCVD growth, the Ni foil is immersed in a ferric chloride solution, and the MGF is detached from the Ni foil in a short time (Figure 1d). Free-standing sandwich-structured HCF (MGF/PACF/MGF) can be obtained as the Ni foil is completely etched (Figure 1e). On the other hand, after the removal of the MGFs, free-standing PACF forms as the Ni foil is completely etched (Figure 1f–1i). The formation process of the PACF can be described as following: first, Ni atoms dissolve in ferric chloride solution (Figure 1f) and carbon atoms appear on the surface of the Ni foil; then, carbon atoms connect with each other to form carbon particles (Figure 1g) and carbon film (Figure 1h). During corrosion process, carbon atom bonds fairly readily with other carbon atoms, rather than Ni atoms, this is because band energy of C–C (347.3 kj/mol) is larger than that of Ni–C (147 kj/mol). In other words, C–C bond is more stable. Finally, a layer of PACF forms (Figure 1i).


Fabrication of thickness controllable free-standing sandwich-structured hybrid carbon film for high-rate and high-power supercapacitor.

Wei H, Wei S, Tian W, Zhu D, Liu Y, Yuan L, Li X - Sci Rep (2014)

Design of free-standing carbon films.Schematic illustration of the fabrication process of HCF and PACF, (a) decomposition of methane, carbon atom adsorption, diffusion and dissolution at growth temperature, (b) graphene growing and a large number of carbon atoms dissolving in Ni foil, (c) part of the carbon atoms segregating/precipitating on Ni surface to form MGF, and another part of the carbon atoms trapped in Ni foil, (d) MGFs detaching from both sides of the Ni foil in ferric chloride solution, (e) free-standing HCF after Ni foil completely etched, (f) etching Ni foil in ferric chloride solution after the removal of MGFs, (g) and (h) etching Ni foil and formation of the PACF, (i) free-standing PACF after Ni foil completely etched.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4231341&req=5

f1: Design of free-standing carbon films.Schematic illustration of the fabrication process of HCF and PACF, (a) decomposition of methane, carbon atom adsorption, diffusion and dissolution at growth temperature, (b) graphene growing and a large number of carbon atoms dissolving in Ni foil, (c) part of the carbon atoms segregating/precipitating on Ni surface to form MGF, and another part of the carbon atoms trapped in Ni foil, (d) MGFs detaching from both sides of the Ni foil in ferric chloride solution, (e) free-standing HCF after Ni foil completely etched, (f) etching Ni foil in ferric chloride solution after the removal of MGFs, (g) and (h) etching Ni foil and formation of the PACF, (i) free-standing PACF after Ni foil completely etched.
Mentions: Figure 1 illustrates a schematic representation of the fabrication process of free-standing HCF. After methane decomposition at growth temperature, carbon atoms adsorb on Ni surface, and then diffuse and dissolve in Ni foil (Figure 1a). Over time, a large number of carbon atoms dissolve in Ni foil because of higher carbon solubility and diffusivity of the Ni metal28293031, and graphene grows on Ni surface at the same time (Figure 1b). It is generally believed that the dissolved carbon atoms segregate/precipitate on Ni surface to form MGF during rapid cooling process28293031. However, it should be noted that this segregation/precipitation process may be limited by: (1) rapidly cooling which may result in a quench effect in which the dissolved carbon atoms lose the mobility232831; and (2) high work pressure and high concentration of carbon atom which may hinder the segregation/precipitation of the dissolved carbon atoms during APCVD process. As a result, only part of the dissolved carbon atoms can segregate/precipitate on the Ni surface to form MGF, and a large number of carbon atoms will be trapped in Ni foil (Figure 1c). After APCVD growth, the Ni foil is immersed in a ferric chloride solution, and the MGF is detached from the Ni foil in a short time (Figure 1d). Free-standing sandwich-structured HCF (MGF/PACF/MGF) can be obtained as the Ni foil is completely etched (Figure 1e). On the other hand, after the removal of the MGFs, free-standing PACF forms as the Ni foil is completely etched (Figure 1f–1i). The formation process of the PACF can be described as following: first, Ni atoms dissolve in ferric chloride solution (Figure 1f) and carbon atoms appear on the surface of the Ni foil; then, carbon atoms connect with each other to form carbon particles (Figure 1g) and carbon film (Figure 1h). During corrosion process, carbon atom bonds fairly readily with other carbon atoms, rather than Ni atoms, this is because band energy of C–C (347.3 kj/mol) is larger than that of Ni–C (147 kj/mol). In other words, C–C bond is more stable. Finally, a layer of PACF forms (Figure 1i).

Bottom Line: Here we demonstrate a simple approach to fabricate free-standing sandwich-structured hybrid carbon film composed of porous amorphous carbon film and multilayer graphene film by chemical vapor deposition in a controllable and scalable way.Supercapacitors assembled by hybrid carbon films exhibit ultrahigh rate capability, wide frequency range, good capacitance performance, and high-power density.Moreover, this approach may provide a general path for fabrication of hybrid carbon materials with different structures by using different metals with high carbon solubility, and greatly expands the application scope of carbon materials.

View Article: PubMed Central - PubMed

Affiliation: School of Physics, Huazhong University of Science and Technology, Wuhan, Hubei. 430074, PR China.

ABSTRACT
Hybrid carbon films composed of graphene film and porous carbon film may give full play to the advantages of both carbon materials, and have great potential for application in energy storage and conversion devices. Unfortunately, there are very few reports on fabrication of hybrid carbon films. Here we demonstrate a simple approach to fabricate free-standing sandwich-structured hybrid carbon film composed of porous amorphous carbon film and multilayer graphene film by chemical vapor deposition in a controllable and scalable way. Hybrid carbon films reveal good electrical conductivity, excellent flexibility, and good compatibility with substrate. Supercapacitors assembled by hybrid carbon films exhibit ultrahigh rate capability, wide frequency range, good capacitance performance, and high-power density. Moreover, this approach may provide a general path for fabrication of hybrid carbon materials with different structures by using different metals with high carbon solubility, and greatly expands the application scope of carbon materials.

No MeSH data available.