An All-Organic Aqueous Battery Powered by Adsorbed Quinone

Abstract

The need for cost-effective, safe energy storage has led to unprecedentedly complex designs of materials and structures to meet stringent requirements. Yet, it remains a question whether we can eventually afford the manufacturing of these new materials and structures at a practical cost. Here, we introduce a new approach toward an all-organic aqueous battery through one-step, solution-phase adsorption. In this battery, two quinone molecules with different redox potentials adsorb onto two porous carbon electrodes to serve as the negative and the positive electrodes. For the negative side, cyclic voltammetry shows a high surface coverage of 66 pmol/cm2 for the adsorbed quinone (anthraquinone-2,7-disulfonate), which enables a stable capacity of 77 mAh/g. The full battery, operating in 1 M sulfuric acid, delivers more than 80% of its capacity at rates of up to 60C, and it retains more than 70% of the capacity after 600 cycles. As the battery adopts the typical build of a supercapacitor, this adsorption-based approach should apply broadly to achieve low-cost, safe storage. The work also provides a quantitative account of the electrochemistry of quinone adsorbed on carbon, which bears significance in the exploitation of quinone molecules in various electrochemical applications.

Emerging trends in sustainable battery chemistries

“…Ideal candidates include batteries using organic electrodes (e.g., naphthalene diimide, phosphaviologens, quinone), which are fully biodegradable and environmentally benign [59,60]. Aqueous based electrolytes should also be adopted to avoid hazardous organic solvent exposure to the environment during disposal [61,62]. Unfortunately, research into organic batteries remains in its infancy and major challenges with organic batteries are that most of them operate at lower cell voltages (<3 V) and with limited specific capacities (<250 mAh/g), limiting their energy densities [61,62].…”

“…Aqueous based electrolytes should also be adopted to avoid hazardous organic solvent exposure to the environment during disposal [61,62]. Unfortunately, research into organic batteries remains in its infancy and major challenges with organic batteries are that most of them operate at lower cell voltages (<3 V) and with limited specific capacities (<250 mAh/g), limiting their energy densities [61,62]. Various doping strategies and the utilization of organic radicals are currently being developed to improve reversible capacities as well as to increase cell operating voltage [62].…”

Bioderived Molecular Electrodes for Next‐Generation Energy‐Storage Materials

“…The solubility of quinones, viologens, flavins, and other natural/biological redox‐active species in acidic or alkaline pH electrolytes make them excellent candidates for organic aqueous flow batteries (schematic shown in Figure ). Compared with inorganic RFB systems, an organic RFB paired with aqueous electrolyte is of low cost, with enhanced power density, improved safety, and environmental benignity .…”

Pseudocapacitive Redox Polymers as Battery Materials: A Proof‐of‐Concept All‐Polymer Aqueous Battery

“…Depending on the redox polymer chemistry, electrolyte and battery operating conditions, a range of cell voltages has been reported for different all‐organic configurations. For aqueous systems cell voltages usually extend over a range of 0.7 V [25] to 1.3 V, [17] with the exception of redox flow batteries where cell voltages up to 1.4 V have been realized [26] . Considering the design flexibility and tuneable redox properties of polymer materials, the field of organic redox chemistry still holds potential for new innovative electrode materials outside the classes of quinone or radical polymers for applications in aqueous all‐polymer batteries.…”