Affiliation:
1. Altris AB Kungsgatan 70b 753 18 Uppsala Sweden
2. Department of Chemistry-Ångström Laboratory Uppsala University Lägerhyddsvägen 1, Box 538 SE-75121 Uppsala Sweden
3. LiFeSiZE AB Lefflersgatan 3A 754 50 Uppsala Sweden
Abstract
AbstractElectrolytes based on sodium bis(oxolato)borate (NaBOB) in organophosphates (trimethyl phosphate and triethyl phosphate (TEP)) have shown promise in sodium‐ion batteries when compared to conventional electrolytes in that they are fire resistant, fluorine‐free and are of lower toxicity. However, these electrolytes tend to exhibit low initial Coulombic efficiency and high overpotentials. We have here demonstrated that NaBOB in TEP can be used in cells with near‐commercial capacity loadings. Furthermore, we have shown that formation cycle conditions have a significant positive effect on the cell performance in these higher mass loading cells, and that modification of the formation cycle conditions can be used to increase the capacity retention, lower the overpotentials, and as such increase the rate capability. The viability of optimized formation protocols was also demonstrated in scaled up prototype cells.
Subject
Electrochemistry,Electrical and Electronic Engineering,Energy Engineering and Power Technology