Convenient modification of carbon fiber surface properties via Ar plasma for superior all-solid-state supercapacitor
摘要
To boost the electrochemical performance of carbon fiber-based supercapacitors, a green and convenient argon (Ar) plasma irradiation strategy was employed to modify the carbon fibers surface. The modified carbon fibers were further assembled into self-supporting all-solid-state supercapacitors (ASSSs). The effects of plasma power and duration on the surface structure and electrochemical properties of the carbon fibers were systematically investigated. The optimization of plasma treatment parameters significantly enhances the surface electrochemical activity of carbon fibers by constructing abundant active sites and tailoring the surface topography. The ASSSs fabricated from carbon fibers treated at the optimal parameters (200 W, 180 s) deliver the best electrochemical performance. At a low scan rate of 10 mV s−1, the device achieves a high areal specific capacitance of 29.2 mF cm−2, which is approximately three times larger than that of the ASSSs based on untreated carbon fibers (9.9 mF cm−2). Besides, the modified carbon fiber-based ASSSs exhibit excellent cycling durability with a capacitance retention of 87.6% after 5000 consecutive charge–discharge cycles. In terms of energy storage characteristics, the optimized device yields an areal energy density of 4.1 μWh cm−2 at an areal power density of 150 μW cm−2, realizing a favorable balance between energy and power performance. This work verifies that moderate Ar plasma modification can effectively engineer the surface chemistry and microstructures of carbon fibers, which in turn induces a remarkable enhancement in the electrochemical performance of carbon fiber-based ASSSs. This modification approach provides a feasible and efficient strategy for the development of high-performance flexible energy storage devices.