Cyanoethyl Cellulose Reinforced Polymerizable Deep Eutectic Solvent Gel Electrolytes for High-energy-density Sodium-ion Batteries
Zhichen Ba
Åbo Akademi University
Solid-state sodium-ion batteries using gel electrolyte with improved safety and high theoretical capacity are considered as the next generation of high-energy-density batteries. However, the inferior interfacial stability and sharp drop in conductivity at low temperatures hinder their practical applications. In this study, a NaTFSI/hydroxyethyl methacrylate polymerizable deep eutectic solvent is used to construct a low-temperature-resistant gel electrolyte by introducing cyanoethyl cellulose network, which aims to promote the dissociation of salts and thus improving the ionic conductivity remarkably (0.66 mS cm-1 at 25 oC). The interface is reinforced after initiating polymerization under UV to prevent sodium dendrites. Furthermore, an extremely wide high thermal stability are proved by low freezing point at -70 oC and non-decomposition temperature at 300 oC. This study provides a broader promise towards safe, low-cost, and high-performance electrolytes in sodium-ion batteries.