Activated Carbons with Tailored Hierarchical Pore Structures and Surface Modification by Atomic Layer Deposition for High-Performance Supercapacitor

events hall

Mr. Fuming Zhang

12.6.22

Seminar by ZOOM

14:30

Supercapacitors are widely used in military, aerospace, rail transportation and many other fields due to their ultra-high-power characteristics, ultra-long cycle life and wide application temperature range. However, their low energy density limits its application as a single energy storage device. It is essential to greatly increase the energy density while maintaining high power and long cycle life. Improving specific capacitance and working voltage are two main ways to improve the energy density of supercapacitors. Electrode materials play a significant role in boosting the capacitive performance. This work attempted both electrode surface chemistry to enable a higher working voltage and hollow-fiber porous design to achieve higher surface area. By introducing a combined method of oxygen plasma and Al2O3 atomic layer deposition (ALD) on commercial activated carbon (AC) electrodes, we reduced the impedance and improved the cycle stability of the AC-based EDLC. Merely tuning the oxygen-plasma treatment time can precisely change the defect structure and thereby the microstructures of AC electrode. Such an approach developed the first-operational AC electrode having more defects and ALD passivation resulting in an outstanding rate performance and cycling stability. Subsequently, we reported a hollow-fiber hierarchical porous carbon using the Metaplexis Japonica shell, which exhibits an ultra-high specific surface area to enhance the capacitance of EDLC. The tailored hierarchical porous carbon is compatible with different sizes of ions in organic electrolytes and ionic liquid.

Supervisor: Prof. Yair Ein-Eli

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