3D printable polymer electrolyte hydrogel for zinc-ion battery

Abstract

The increasing use of electronic wearable devices for diverse applications leads to demand for new energy storage, especially flexibility and wearable design. Zinc-ion batteries (ZIBs) are significant potential energy storage for such applications. However, the lack of stable and durable electrolytes for flexible ZIBs significantly limits their applications. Gel polymer electrolytes can challenge these limitations; however, it offers low ionic conductivity compared to conventional liquid electrolytes. Increasing porosity is one of the proposing approaches to improve the ion mobility interconnects pathway. The 3D printing process is a versatile technology that can be applied to gel-like polymers. This research aims to develop 3D-printable flexible hydrogel from polyacrylamide and use it as polymer electrolytes hydrogel for ZIBs. The hydrogel with designed porosity was fabricated using digital light processing (DLP) 3D printing. The design structure of polymer electrolyte hydrogel with 3D printing effectively improves the electrochemical properties. In particular, the ionic conductivity reaches 28.10 mScm-1, equivalent to the currently developed gel polymer electrolytes. Both electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) results proved that the higher porous structure enhanced the capability of electrolytes absorption and increased the contact area, thus, improving the diffusion of Zn2+ ions. GCD results evidenced the specific capacity of 3D printed 40% porosity electrolyte hydrogel of 161.4 mAh/g at 1 A/g.