Recent progress in aqueous monovalent-ion batteries with organic materials as promising electrodes

In an effort to search for low-cost and sustainable energy storage systems, organic material-based aqueous batteries have attracted numerous attentions. In particular, aqueous monovalent-ion organic batteries, including either anion or cation storage, have been recently investigated with the employment of different redox-active organic materials. In this review, the recent progress in aqueous monovalent-ion batteries with organic materials are summarized. The different configurations of aqueous monovalent ion organic batteries are also introduced with the explanation of different working mechanisms. A comprehensive overview of the reported redox-active organic materials, mainly conductive or conjugated polymers, nitroxide radicals, and carbonyl compounds are presented. Moreover, the remaining challenges and recommendations with respect to aqueous monovalent-ion batteries are also discussed in the conclusion. (C) 2020 Elsevier Ltd. All rights reserved.