Polyacrylonitrile-Nanofiber-Based Gel Polymer Electrolyte for Novel Aqueous Sodium-Ion Battery Based on a Na(4)Mn(9)O(18) Cathode and Zn Metal Anode

A gel polymer electrolyte was formed by trapping an optimized Na(+)/Zn(2+) 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 Na(4)Mn(9)O(18) cathode. The nanorod-like Na(4)Mn(9)O(18) was synthesized by a hydrothermal soft chemical reaction. The structural and morphological measurement confirmed that the highly crystalline Na(4)Mn(9)O(18) nanorods are uniformly distributed. Electrochemical tests of Na(4)Mn(9)O(18)//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(−1) after 200 cycles at a high cycling rate of 1 C. Our results demonstrate that the Na(4)Mn(9)O(18)//Zn gel polymer battery is a promising and safe high-performance battery.