A Metal-Free Battery with Pure Ionic Liquid Electrolyte

Abstract

Metal or metal-ion based battery represents the mainstream battery technology, in which metal-ion either participates in electrode redox or acts as the charge carrier in electrolyte. The principle guides the battery designs and leads to the most widely adopted battery construction of metal-ion acceptor/metal salt in appropriate solvent/metal-ion donor. Though with significant progress, many issues have been incurred, including dendrite growth, SEI corruption, and safety concerns. In this paper, the intercalation/deintercalation of organic cations other than metal ions is revealed and has been fulfilled in an all-organic battery composing of organic anode/cathode, and pure ionic liquid electrolyte. The metal-free and solvent-free concept has been demonstrated by polyimide/EMITFSI/polytriphenylamine full-cell, through which capacity approaching theoretical value, rate capability up to 200 C, cycling life longer than 5000 cycles, and remarkable low-temperature performance has been achieved. Our pioneer work provides an alternate way of developing future efficient, safe, green, and versatile rechargeable batteries.

Keywords: metal-free, organic cation intercalation, ionic liquid, organic electrode material, green battery