Porous structural effect of carbon electrode formed through one-pot strategy on performance of ionic liquid-based supercapacitors

Understanding of porous structural effect of carbon electrode on the electrochemical performance of ionic liquids-based supercapacitors is essential for the design of carbon-based electrode materials due to the large ion size and high viscosity induced sluggish ion diffusion rate. Herein, we report the electrochemical performance of supercapacitors using imidazolium-type ionic liquid as electrolyte and nitrogen-doped porous carbon with tunable porous structure as model electrodes synthesized by a one-pot multiscale silica-templated strategy through pH regulation. The results reveal that the porous structure has significant influence on the electrochemical performance of the accordingly assembled supercapacitors. Carbon-based electrode materials with interconnected macro-, meso- and micro-pores can significantly improve the energy density of the thus-assembled symmetric supercapacitor devices, delivering an energy density of 93 Wh.kg(-1) at power density of 1.75 kW.kg(-1). Benefiting from the interconnected multiscale pores, the assembled device can provide 48 Wh.kg(-1) at a power density of 87 kW.kg(-1) and lighten 20 white LEDs efficiently. Moreover, the assembled supercapacitor retains 88% of its initial capacitance after 10,000 continuous charge-discharge cycles at 10 A.g(-1).

Automated summary

Understanding the porous structural effect on the electrochemical performance is crucial for designing carbon-based electrode materials for ionic liquids-based supercapacitors. Carbon electrodes with interconnected macro-, meso- and micro-pores can significantly improve the energy density and power density of supercapacitor devices. By controlling the multiscale pores, the performance of carbon-based electrode materials can be enhanced efficiently.