High-stability zinc anodes modulated by solvation structure and interface chemistry toward printable zinc-ion capacitors

Abstract

Despite the well-known advantages of aqueous zinc-ion energy storage devices, their development is hindered by challenges such as zinc dendrite formation and side reactions. Moreover, reducing costs and improving efficiency are essential to achieving their commercialization. This study addresses the issues associated with conventional zinc sulfate electrolytes by introducing a safe and moderate concentration of glycerophosphocholine (G) as an additive. Experimental characterization and theoretical calculations show that additive G molecules regulate the solvation structure of zinc ions and modify the adsorption behavior of zinc metal at the electrolyte interface. This dual action suppresses the decomposition of active water molecules and guides the oriented deposition of zinc ions. From the perspective of practical application, high-performance zinc-ion hybrid capacitors are fabricated using fully printed electrodes via a cost-effective and scalable screen-printing method and possess a high capacity retention of 87.09 % after 6000 cycles. These devices demonstrate exceptional electrochemical performance and can accelerate the lab-to-fab translation process, showing great potential for commercialization.