Development of covalent-bonded organic/carbon anode for sodium-ion battery

Sodium (Na) organic batteries have attracted great attention because of high abundance of Na, low-production cost, and structure diversity of organic electrode materials. Despite the efforts on organic Na-ion batteries, organic electrodes are still vulnerable to conventional electrolytes, and have a low conductivity which leads to continuous capacity fading and low-rate capability, respectively. In this study, we aimed to reduce solubility in electrolyte and enhance electrical conductivity of organic electrode by anchoring 2,5- dihydroxyterephtalic acid (DHTPA) to carbon black via esterification. Then, the sodiated DHTPA/CB powder was evaluated for an anode in Na-ion battery. The covalent-bonded organic/carbon black electrode retained 90 % of the initial capacity even after 100 cycles, and also showed excellent rate capability up to 1500 mA/g. The result sheds light on the commercialization of organic-based Na-ion batteries, and their large-scale applications to electric vehicles (EVs) and energy storage systems (ESSs) markets.