External and internal stimuli for enhanced supercapacitor performance

Use of internal and external stimuli can be an alternative tool to address the limitations of a supercapacitor for its enhanced electrochemical properties. Influence of internal stimuli, such as redox active dopants and vacancies, can alter the electronic structure or phase of the electrode material, leading to an improved redox behavior of the pseudo-capacitors by virtue of electron polarizations, leading to a better electrochemical charge transfer kinetics. On the other hand, external stimuli, such as applied magnetic field, can alter the diffusion characteristics of the active ions in the electrolyte, thereby changing the ion/charge rearrangement and ion diffusion characteristics within supercapacitor electrodes. This Perspective emphasizes the importance of these two aspects, supported by an in-depth literature review to give a comprehensive overview of internal and external stimuli effects in designing the model systems for future electrochemical applications.