Progress on Engineering Low-Temperature Electrolyte for High-Performance Supercapacitors

The ion dynamics within electrolytes significantly influenced by external temperature variations represent a crucial aspect of electrochemistry. Low-temperature-induced solidification of conventional electrolyte solutions reduces the flowability and conductivity of the electrolyte, limiting the power density of supercapacitors. Addressing this challenge, designing electrolytes that can withstand such low-temperature environments has become a priority. Our review offers an extensive overview and insightful analysis of recent innovations in low-temperature supercapacitors, focusing on the core mechanisms and strategies that bolster low-temperature endurance. The analysis begins by delving into the failure mechanisms of electrolytes and their interfaces with electrodes under cold conditions. Following this, a comprehensive review of diverse strategies for enhancing ion conductivity at low temperatures is presented, covering both traditional and unconventional approaches, focusing on optimizing the composition and structural design of electrolytes. Moreover, the review discusses enhancing the dynamics of the electrode/electrolyte interface under low temperatures through the precise regulation of the solvation structure of ions within the electrolyte. Concluding, it highlights current limitations and suggests future directions for research, aiming to guide the advancement of supercapacitors in low-temperature applications.