Kelchtermans An-Sofie, De Sloovere Dries, Mercken Jonas, Vranken Thomas, Mangione Gianfabio, Joos Bjorn, Vercruysse Willem, Vandamme Dries, Hamed Hamid, Safari Mohammadhosein, Derveaux Elien, Adriaensens Peter, Van Bael Marlies K, Hardy An
Institute for Materials Research (imec-imomec), Design and Synthesis of Inorganic Materials (DESINe), Hasselt University, Martelarenlaan 42, Hasselt B-3500, Belgium.
Energyville, imo-imomec, Thor Park 8320, Genk B-3600, Belgium.
ACS Omega. 2024 Oct 1;9(41):42343-42352. doi: 10.1021/acsomega.4c02896. eCollection 2024 Oct 15.
Sodium-ion batteries (SIBs) are a more sustainable alternative to lithium-ion batteries (LIBs) considering the abundance, global distribution, and low cost of sodium. However, their economic impact remains small compared to LIBs, owing in part to the lag in materials development where significant improvements in energy density and safety remain to be realized. Deep eutectic solvents (DESs) show promise as alternatives to conventional electrolytes in SIBs because of their nonflammable nature. However, their practical application has thus far been hindered by their limited electrochemical stability window. In particular, DESs based on -methylacetamide have thus far been reported not to be stable with sodium metal. In contrast, this work reports a superconcentration strategy where sodium-ion conducting DESs, based on the dissolution of NaFSI in -methylacetamide, are simultaneously stable with sodium metal and Prussian blue as state-of-the-art positive electrode material. At 60 °C, the nonflammable DES outperforms a conventional liquid electrolyte in terms of rate performance and capacity retention. Therefore, these novel DES compositions pave the way for the use of DESs in practical applications with an improved safety and sustainability.
考虑到钠的储量丰富、全球分布广泛且成本低廉，钠离子电池（SIBs）是锂离子电池（LIBs）更具可持续性的替代品。然而，与锂离子电池相比，它们的经济影响仍然较小，部分原因是材料开发滞后，能量密度和安全性仍有待大幅提高。深共熔溶剂（DESs）因其不可燃的性质，有望成为钠离子电池中传统电解质的替代品。然而，它们的实际应用迄今为止受到其有限的电化学稳定性窗口的阻碍。特别是，迄今为止报道的基于N-甲基乙酰胺的深共熔溶剂与金属钠不稳定。相比之下，这项工作报道了一种超浓缩策略，即基于NaFSI溶解在N-甲基乙酰胺中的钠离子传导深共熔溶剂，与金属钠和作为最先进正极材料的普鲁士蓝同时保持稳定。在60°C下，这种不可燃的深共熔溶剂在倍率性能和容量保持率方面优于传统液体电解质。因此，这些新型深共熔溶剂组合物为在实际应用中使用深共熔溶剂并提高安全性和可持续性铺平了道路。
