Welch Jonas, van Ekeren Wessel W A, Mindemark Jonas, Younesi Reza
Department of Chemistry-Ångström Laboratory, Uppsala University, Uppsala, Sweden.
Commun Chem. 2025 Apr 26;8(1):127. doi: 10.1038/s42004-025-01515-0.
Sodium-ion batteries are a promising alternative to lithium-ion batteries due to their potential for lower cost and greater sustainability. However, achieving stable cycling performance, particularly at high mass-loadings and elevated temperatures, remains a challenge. The stable cycling of high mass-loading sodium-ion battery cells is here made possible by addition of prop-1-ene-1,3-sultone (PES) to a non-flammable and fluorine-free electrolyte solution of sodium bis(oxalato)borate (NaBOB) salt in triethyl phosphate (TEP). This study investigates the thermal stability and electrochemical performance of such electrolyte at 40 °C and 55 °C, contrasting their performance with base NaBOB in TEP with and without ethylene sulfate (DTD) additive and with a reference carbonate electrolyte of NaPF in ethylene carbonate:diethylene carbonate (EC:DEC). Nuclear Magnetic Resonance spectroscopy was used to reveal degradation products formed in the electrolyte following a 4-weeks storage at 55 °C. Results from galvanostatic cycling at 55 °C demonstrated comparable performance of NaBOB-TEP + PES electrolyte and the reference carbonate electrolyte. The internal cell resistance was initially lower when cells were cycled at 55 °C than at 40 °C for all studied electrolytes.
钠离子电池因其具有降低成本和更高可持续性的潜力，是锂离子电池的一种有前景的替代方案。然而，实现稳定的循环性能，尤其是在高负载量和高温下，仍然是一个挑战。通过在磷酸三乙酯（TEP）中由双（草酸根）硼酸酯钠（NaBOB）盐组成的不可燃且无氟的电解质溶液中添加1,3 - 丙磺酸内酯（PES），使高质量负载的钠离子电池单元实现稳定循环成为可能。本研究考察了这种电解质在40℃和55℃下的热稳定性和电化学性能，并将其性能与在TEP中添加和不添加硫酸乙烯酯（DTD）添加剂的基础NaBOB以及碳酸乙烯酯：碳酸二乙酯（EC:DEC）中的NaPF6参考碳酸盐电解质进行对比。核磁共振光谱用于揭示在55℃下储存4周后电解质中形成的降解产物。在55℃下恒电流循环的结果表明，NaBOB - TEP + PES电解质和参考碳酸盐电解质具有可比的性能。对于所有研究的电解质，当电池在55℃下循环时，其内部电池电阻最初低于在40℃下循环时的电阻。
