Inorganic-organic composite solid electrolyte based on cement and Polyacrylamide prepared by a synchronous reaction method

Inorganic-organic composite solid electrolyte (CSE) has a high potential for future energy storage. Compared with ceramic-based CSE, cement-based CSE can be prepared at room temperature, which is conducive to incorporation of polymer into CSE. However, the content of polymer in CSE is limited to the small level, which hinders the performance of the electrolyte. In this work, a novel synchronous reaction method (SRM) is proposed to prepare CES, which can exceed the content limit of polymer remarkably. Through SRM, cement hydration and polymer polymerization are simultaneously carried out to solve the problem of cement slurry fluidity caused by the addition of polymer. Infrared and 1H-NMR spectra confirm that the CSE has been successfully prepared, and Polyacrylamide (PAM) can be detected in CSE. GPC results show that the molecular mass of PAM in the CSE increases with the monomer content. SEM results reveal that PAM and hardened cement are well combined and evenly distributed at the micro level. The microstructure, ionic conductivity and compressive strength of CSE change considerably with the polymer content. In general, with the increase of polymer content, the internal structure is gradually improved, also the ionic conductivity and compressive strength are improved remarkably. The multi-functionality results indicate that the CSE prepared by synchronous reaction method with 20 wt.% PAM shows the best combination of the ionic conductivity (10.52 mS/cm) and the compressive strength (53.78 MPa). An all-solid supercapacitor (ASS) was assembled by the solid electrolyte and rGO/Ni foam composite electrodes, which shows good electrochemical energy storage performance. Therefore, the solid electrolyte synthetized with SRM provides a promising way for the application of all-solid electrochemical energy storage.