An All-Organic Non-aqueous Lithium-Ion Redox Flow Battery

A non-aqueous lithium-ion redox flow battery employing organic molecules is proposed and investigated. 2,5-Di-tert-butyl-1,4-bis(2-methoxyethoxy)benzene and a variety of molecules derived from quinoxaline are employed as initial high-potential and low-potential active materials, respectively. Electrochemical measurements highlight that the choice of electrolyte and of substituent groups can have a significant impact on redox species performance. The charge-discharge characteristics are investigated in a modified coin-cell configuration. After an initial break-in period, coulombic and energy efficiencies for this unoptimized system are similar to 70% and similar to 37%, respectively, with major charge and discharge plateaus between 1.8-2.4 V and 1.7-1.3 V, respectively, for 30 cycles. Performance enhancements are expected with improvements in cell design and materials processing.