Electrochemical Energy Storage with Mediator-Ion Solid Electrolytes

Abstract

From an electrochemical point of view, many liquid-phase or gas-phase materials exhibiting a high operating voltage and a high intrinsic capacity can potentially be used as electrodes for the development of high energy, low-cost aqueous batteries. However, under the traditional battery operating principle with a porous separator, there is a tendency of shuttling of liquid or gaseous electrodes through the porous separator, which strictly limits the application of liquid-phase or gaseous-phase materials for the development of energy storage systems.1 We have recently developed a new mediator-ion battery concept with alkali-metal-ion (Li+-ion or Na+-ion) solid-electrolyte separators.2 The anode and cathode reactions of the redox couples can be maintained by a shuttling of the alkali-metal ion through the solid-state electrolyte between the catholyte and the anolyte. This unique battery-development strategy can not only eliminate the chemical-crossover problem of the liquid or gaseous reactants, but also circumvent the metal-dendrite problem.3 Based on the unique features, the “mediator-ion” battery concept offers a versatile approach for the development of a broad range of new battery systems. This presentation will first introduce the basic concept and operating principle of the mediator-ion battery. Then a sequence of mediator-ion batteries with a variety of redox couples we recently developed will be demonstrated.4-8 These novel mediator-ion batteries can be classified into four categories including, (1) meatal anode – inorganic liquid cathode batteries (zinc – bromine, zinc – Ferricynide, and zinc – polysulfide batteries), (2) meatal anode – organic liquid cathode batteries (zinc – quinone batteries), (3) meatal anode – gaseous cathode batteries (zinc – air and iron – air batteries), and (4) organic liquid anode – gaseous cathode batteries (quinone – air and methyl viologen – air batteries). At the end of this presentation, future prospects of this novel battery development strategy will be discussed. References Manthiram, X. Yu and S. Wang, Nat Rev Mater, 2017, 2, 16103.W. Yu and A. Manthiram, Joule, 2017, 1, 453-462.W. Yu, M. M. Gross, S. F. Wang and A. Manthiram, Adv Energy Mater, 2017, 7, 1602454.W. Yu and A. Manthiram, ACS Appl. Energy Mater, 2018, 1, 273−277.W. Yu and A. Manthiram, ACS Energy Letters, 2017, 2, 1050-1055.W. Yu and A. Manthiram, Advanced Sustainable Systems, 2017, 1, 1700082.W. Yu and A. Manthiram, Sustain Energ Fuels, 2018, 2, 1452-1457.W. Yu and A. Manthiram, ACS Appl. Energy Mater, 2018, 1, 2424–2428.