Fabrication of ultrahigh mass-loaded flexible self-supported electrodes for high-performance supercapacitors

Abstract

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  A binder-free 3D interpenetrating conductive network (CNT/GO) network is constructed on carbon cloth serve as stable scaffold for high-loading PANI deposition.
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  The optimized electrode achieves ultrahigh mass loading of 22 mg cm^–2 and exhibits outstanding areal capacitance and remarkable rate capability.
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  The electrode delivers a high areal capacitance of 4116 mF⋅cm^–2 at 5 mg⋅cm^–2.
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  It retains 81% of initial capacitance after 10,000 cycles at 40 mA⋅cm^–2.

The rapid advancement of flexible and wearable electronics has intensified the demand for energy storage devices that combine high-mass-loading active materials with superior rate performance. However, high-mass-loading electrodes often suffer from slow ion diffusion and inefficient electron conduction, which severely limit their rate capability and practical application. To overcome these limitations, we construct a binder-free three-dimensional (3D) interconnected network on functionalized carbon cloth (FCC) by integrating one-dimensional (1D) carbon nanotubes (CNTs) and two-dimensional (2D) graphene oxide (GO). This architecture serves as a robust scaffold to enable efficient polyaniline (PANI) deposition. Experimental results reveal that 1D CNTs function as conductive interlinks bridging 2D GO nanosheets and the FCC substrate, effectively lowering the charge transfer resistance (R_ct) and establishing unobstructed transport channels for both electrons and electrolyte ions. Owing to this hierarchical structural design, the electrode achieved an ultrahigh mass loading of 22 mg⋅cm⁻² after 3600 s electrodeposition. Electrochemical measurements in a three-electrode configuration delivered a remarkable areal capacitance of 4116 mF⋅cm⁻² at a current density of 5 mA⋅cm⁻². Notably, it maintains a capacitance retention of 85.2% even at an ultrahigh current density of 100 mA⋅cm⁻², demonstrating excellent rate performance. A symmetric flexible solid-state supercapacitor (FSSC) assembled using this electrode exhibits a high areal capacitance of 1123 mF⋅cm⁻² at 5 mA⋅cm⁻² with 83.5% capacitance retention at 100 mA⋅cm⁻², along with a maximum areal energy density of 190.83 μWh⋅cm⁻² and a power density of 2000 μW⋅cm⁻². These results highlight the great potential of the proposed electrode for high-performance flexible energy storage applications.

The rapid advancement of flexible and wearable electronics has intensified the demand for energy storage devices that combine high-mass-loading active materials with superior rate performance. However, high-mass-loading electrodes often suffer from slow ion diffusion and inefficient electron conduction, which severely limit their rate capability and practical application. To overcome these limitations, we construct a binder-free three-dimensional (3D) interconnected network on functionalized carbon cloth (FCC) by integrating one-dimensional (1D) carbon nanotubes (CNTs) and two-dimensional (2D) graphene oxide (GO). This architecture serves as a robust scaffold to enable efficient polyaniline (PANI) deposition. Experimental results reveal that 1D CNTs function as conductive interlinks bridging 2D GO nanosheets and the FCC substrate, effectively lowering the charge transfer resistance (R_ct) and establishing unobstructed transport channels for both electrons and electrolyte ions. Owing to this hierarchical structural design, the electrode achieved an ultrahigh mass loading of 22 mg⋅cm⁻² after 3600 s electrodeposition. Electrochemical measurements in a three-electrode configuration delivered a remarkable areal capacitance of 4116 mF⋅cm⁻² at a current density of 5 mA⋅cm⁻². Notably, it maintains a capacitance retention of 85.2% even at an ultrahigh current density of 100 mA⋅cm⁻², demonstrating excellent rate performance. A symmetric flexible solid-state supercapacitor (FSSC) assembled using this electrode exhibits a high areal capacitance of 1123 mF⋅cm⁻² at 5 mA⋅cm⁻² with 83.5% capacitance retention at 100 mA⋅cm⁻², along with a maximum areal energy density of 190.83 μWh⋅cm⁻² and a power density of 2000 μW⋅cm⁻². These results highlight the great potential of the proposed electrode for high-performance flexible energy storage applications.

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