Polyacrylonitrile-Nanofiber-Based Gel Polymer Electrolyte for Novel Aqueous Sodium-Ion Battery Based on a Na4Mn9O18 Cathode and Zn Metal Anode

A gel polymer electrolyte was formed by trapping an optimized Na+/Zn2+mixed-ion aqueous electrolyte in a polyacrylonitrile nanofiber polymer matrix. This electrolyte was used in a novel aqueous sodium-ion battery (ASIB) system, which was assembled by using a zinc anode and Na4Mn9O18cathode. The nanorod-like Na4Mn9O18was synthesized by a hydrothermal soft chemical reaction. The structural and morphological measurement confirmed that the highly crystalline Na4Mn9O18nanorods are uniformly distributed. Electrochemical tests of Na4Mn9O18//Zn gel polymer battery demonstrated its high cycle stability along with a good rate of performance. The battery delivers an initial discharge capacity of 96 mAh g−1, and 64 mAh g−1after 200 cycles at a high cycling rate of 1 C. Our results demonstrate that the Na4Mn9O18//Zn gel polymer battery is a promising and safe high-performance battery.Keywords:aqueous sodium-ion battery;cathode;gel polymer electrolyte;Na4Mn9O18nanorod;polyacrylonitrile nanofiber