In this study, we focus on the activation of bio-based cellulosic materials with potassium hydroxide (KOH) and the optimization of the KOH/cellulose ratio to yield the best electrochemical performance. The synthesis of electrodes with high specific capacitances and power densities has been achieved upon optimizing the porous morphology of the carbons via activation with different KOH loadings. Various characterization techniques of the carbons were carried including transmission electron microscopy, x-ray tomography, mercury intrusion porosimetry and nitrogen adsorption-desorption isotherms. The effect of each of the specific surface areas, pore size distribution, porosity and tortuosity on the electrochemical performance was then investigated in three-electrode systems and coin cells. The samples with KOH/cellulose ratios of 0.5:1 and 1:1 proved to acquire the best performance with specific capacitances as high as 187 F g-1 at current density of 1 A g-1 and a retention rate of 72%. This was attributed to the hierarchical porous network structure, high surface areas and low cell resistances. It was established that a well-balanced porous network structure of micro-, meso- and macro-pores is crucial for achieving high electrochemical performance, specifically at low current densities.
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