Redox flow batteries (RFBs) are promising for the large-scale storage of renewable energies. Nonaqueous RFBs can achieve higher voltages and are more suitable for extreme environments than their aqueous counterparts. In this work, the first nonaqueous Mg flow battery with a polymer catholyte is reported, by integrating a Mg foil anode, and a porous membrane, with a polymer solution catholyte. The battery can deliver a voltage of 1.74 V, a capacity of 250 mAh/L, and a cycle life of 50 cycles. This work demonstrates the feasibility of Mg flow batteries and provides a unique direction for flow battery research.
Non-aqueous redox flow batteries (RFBs) are emerging electrochemical technologies for grid energy storage. Non-aqueous Mg RFBs that use Mg metal as the anode are especially promising due to various benefits of the Mg metal anode, including its low potential, high volumetric capacity, SEI-free, highly reversible operation and low cost. Despite the potential, there are rarely any studies on developing non-aqueous Mg RFBs. Herein, a non-aqueous Mg redox flow battery using a polymer catholyte is reported. Through rational molecular engineering, a carbonyl-based moiety is combined with a polyethylene glycol moiety to achieve a polymer with high voltage and high solubility in the ether-based electrolyte. A series of polymers with different polyethylene glycol chain lengths are synthesized and their performances are measured first at the molecular level, and then at the device level in a Mg redox flow battery using a Mg foil as the anode, the polymer solution as the catholyte and a porous membrane as the separator. The flow battery delivers a voltage of 1.8 V, a maximum capacity of 475 mAh/ L, an average Coulombic efficiency of 90.5%, an average voltage efficiency of 67.4%, an energy efficiency of 61.0%, and an energy density of 0.855 Wh/L. Systematic mechanistic studies are performed to understand the performance decay mechanism and possible strategies for future improvement are discussed. This work opens a new avenue for the development of energy storage technologies for grid electricity storage.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.