EFFECT OF WATER-SOLUBLE POLYMER NV-1A ON ELECTROCHEMICAL PARAMETERS OF SULFUR ELECTRODE

• Date: 2021
• Main Authors: Krushevskyi, Oleksandr, Zhou, MiaoMiao, Potapenko, Oleksandr, Potapenko, Anna
• Format: Article
• Language: English
• Published: V.I.Vernadsky Institute of General and Inorganic Chemistry 2021
• Online Access: https://ucj.org.ua/index.php/journal/article/view/382
• Journal Title: Ukrainian Chemistry Journal

Studies have shown the possibility of a long cycle of sulfur electrode with a high content of active material. The use of water-soluble binder material NV-1A leads to the realization of high current loads in the Li-S battery. Impedance spectroscopy has shown that the low coulombic efficiency in the cycling of the sulfur electrode is primarily due to the spontaneous dissolution of sulfur in the electrolyte, which requires high energy consumption when charging the Li-S battery. The reduction of the specific capacity during cycling is associated with the formation and accumulation of non-conductive films of short-chain polysulfides. On the basis of the conducted researches and the review of the literature sources ways of overcoming of this problem are offered. The ability of cycling the sulfur electrodes at the high current loads has been shown. The discharge capacity values of the sulfur electrodes at the current load 790 mA∙cm-2 are 500 і 420 mAh∙g-1 on the 5-th and 100-th cycles, accordingly. Using the method of impedance spectroscopy, it has been supposed that the formation and accumulation of unconductive Li2S2 / Li2S phases is the main process, which induce the quick capacity reduction of Li - S batteries upon cycling.