A Comparative Review of Electrolytes for Organic-Material-Based Energy-Storage Devices Employing Solid Electrodes and Redox Fluids

Abstract

Electrolyte chemistry is critical for any energy-storage device. Low-cost and sustainable rechargeable batteries based on organic redox-active materials are of great interest to tackle resource and performance limitations of current batteries with metal-based active materials. Organic active materials can be used not only as solid electrodes in the classic lithium-ion battery (LIB) setup, but also as redox fluids in redox-flow batteries (RFBs). Accordingly, they have suitability for mobile and stationary applications, respectively. Herein, different types of electrolytes, recent advances for designing better performing electrolytes, and remaining scientific challenges are discussed and summarized. Due to different configurations and requirements between LIBs and RFBs, the similarities and differences for choosing suitable electrolytes are discussed. Both general and specific strategies for promoting the utilization of organic active materials are covered.

Keywords: electrochemistry; energy storage; ionic liquids; polymers; redox chemistry.