Role of aqueous electrolytes on the performance of electrochemical energy storage device

Electrochemical energy storage devices such as supercapacitors attracting a significant research interest due to their low cost, highly efficient, better cyclic stability and reliability. The charge storage mechanism in supercapacitors are generally depends upon absorption/desorption of charges on electrode-electrolyte interface while the pseudocapacitive phenomenon is due to fast redox reactions. Electrochemical performance of the supercapacitors can be enhanced by optimizing the key parameters such as electrode material, activation agent, potential window, type and molar concentration of the electrolytes. Here, we have reported a thorough investigation about the impact of aqueous electrolytes on the performance of energy storage in electrochemical supercapacitors. To the best of our knowledge, aqueous electrolytes have shown a prominent impact on the capacitance of materials. In light of the reported articles, supercapacitor electrode materials have shown high performance in aqueous acidic electrolyte due to their high ionic conductivity. In contrast, electrode materials for supercapacitors have demonstrated low capacitance in neutral aqueous electrolytes due to low molar ionic conductivity. The choice of electrolyte is an important parameter to achieve high performance energy storage devices for future technological applications. (C) 2019 Elsevier B.V. All rights reserved.