A self-healing and robust aqueous network binder for aqueous energy storage devices

Abstract

A new aqueous network binder with good self-healing and robust performance is developed for high-performance aqueous energy storage devices. Comparing to conventional polymeric binders, such as polyvinylidenefluoride (PVDF) or polyacrylic acid carboxymethyl cellulose (CMC), the present aqueous network binder exhibit higher adhesive strength of ca.1.1 MPa, better hydrophilicity (i.e. CA = 40.7°), and enhanced self-healing property. When applied to supercapacitors, the resulting all-solid-state supercapacitor has a larger areal specific capacitance of 696.6 mF/cm2, while maintaining a retention rate of 90.3% after 3000 cycles. Furthermore, the mild aqueous zinc button cell based on this binder also exhibits a large capacity of 48.8 mAh/g and a retention rate of 83.4% after 1000 cycles. Such electrochemical performance can be attributed to the adopted binder that facilitates the diffusion of stored ions from the electrolyte to the active materials, while its hydrophilicity and self-healing performance prevents damage caused by the swelling of the electrode. This work thus provides a new avenue for the development of aqueous binders with desired properties for aqueous energy storage devices.