Long Cycle-Life Aqueous Batteries Enabled by Organic Electrode Materials

The integration of intermittent renewable energy resources (e.g. solar and wind) requires the deployment of a reliable energy storage system. Aqueous batteries with the merits of safety, low-cost, fast charge-discharge ability, and environmental friendliness, are one of the most competitive technologies for large-scale energy systems. However, their utilization is limited by their short cycle-life. In this dissertation, I first developed two advanced aqueous batteries with long cycle-life taking the advantages of organic electrode materials featuring sustainability, tailorable properties, and environmental benignity. One advanced acidic battery is developed by the successful implementation of quinone-based electrode materials. Starting with exploring quinones as electroactive materials in acidic electrolytes, studying their structural and electrochemical behavior on the molecular level, a high-performance electrode developed based on a quinone (pyrene-4,5,9,10-tetraone core. PTO). I further demonstrate an advanced acidic battery with a superior cycling and high-rate performance using PTO as the negative electrode and PbO2 as the positive electrode over conventional lead-acid batteries while maintaining the specific energy density. The second part of this dissertation is a rocking-chair aqueous battery which uses less-corrosive neutral electrolyte. I demonstrate the feasibility of an innovative aqueous Ca-ion battery in which abundant multivalent Ca-ion is the charge carrier shuttling back and forth between two low-cost electrode materials. An organic imide-based polymer as the anode and copper hexacyanoferrate as the cathode, both prepared using low-cost materials and preparation processes. In the last part, I report a strategy to develop a low-cost and light-weight current collector for the batteries which uses neutral aqueous electrolytes based on a coated aluminum foil. I compare the performance of the cathode electrode prepared on different collectors and demonstrate the superior performance of the electrode using coated aluminum foil over expensive Ti foil and heavy stainless steel. The plausibility to use low-cost and high-performance materials marks an important step toward developing a reliable storage system for large-scale grid applications. I sincerely hope the findings from this dissertation will pave the way towards organic redox materials with practically competitive power/energy density and cycling stability for widespread energy-related applications.