Revealing better organic sodium battery performance in ionic liquid electrolytes

Abstract

The commercialization of sodium ion batteries (SIBs) accelerated the research and development of electrode materials. Organic electrodes have less restriction on the battery system and have received increasing attention. However, how to avoid the dissolution of organic materials in traditional electrolytes is a crucial element. Based on the principle of “like dissolves like”, ionic liquid (IL) electrolytes could bring wide horizons due to differences in polarity. In this study, the sodium storage behavior of pillar[5]quinone (P5Q) and 0.3 M NaTFSI-PY13TFSI electrolyte with a large difference in polarity was investigated. Compared with traditional electrolytes, the record-high capacity was 258 mA h g⁻¹ over 500 cycles at 0.2 C, and the pseudocapacitance contribution can reach 74% at 1 mV s⁻¹, revealing its superb storage capacity. Therefore, IL electrolytes would vigorously promote the commercialization of organic electrodes.