Flexible Quasi-solid-state Aqueous Zn-based Batteries: Rational Electrode Designs for High Performance and Mechanical Flexibility

Abstract With the rapid surge in demand for portable and wearable electronics, there is an apparent requirement for efficient power supplies with high performance, mechanical flexibility and long term safety. To this context, mechanically flexible quasi-solid-state aqueous Zn-based batteries have been regarded as a class of promising energy storage devices (ESDs) for these portable and wearable electronics, owing to their exceptionally inherent safety of employing aqueous-based electrolytes and unique advantages of using low-cost zinc anodes. Arising from the extensive research and development over the past several years, their overall performance is becoming at least comparable with those state of the art competitors, including an energy density in the range of 100 to 300 Wh kg-1, and cycling-ability of ∼2000 cycles. Although a couple of previously published review articles have focused on the hot topic addressing rechargeable aqueous Zn-based batteries, a thoroughly comprehensive overview on flexible quasi-solid-state aqueous Zn-based batteries (e.g., Zn-alkaline batteries, Zn-air batteries and Zn-ion batteries) would be timely and essential. Herein, a concise overview on the recent advances in flexible quasi-solid-state aqueous Zn-based batteries is presented from the perspectives of rational designs for both flexible electrodes and devices, together with the challenges and opportunities that remain to be addressed, aiming to shine new light on further development of high-performance flexible aqueous batteries in the coming few years.