Chen Jian, Yang Zhuo, Xu Xu, Qiao Yun, Zhou Zhiming, Hao Zhiqiang, Chen Xiaomin, Liu Yang, Wu Xingqiao, Zhou Xunzhu, Li Lin, Chou Shu-Lei
School of Environmental and Chemical Engineering, Shanghai University, Shanghai, 200444, China.
Institute for Carbon Neutralization, College of Chemistry and Materials Engineering, Wenzhou University, Zhejiang, 325035, China.
Adv Mater. 2024 Jul;36(28):e2400169. doi: 10.1002/adma.202400169. Epub 2024 May 6.
Intrinsically safe sodium-ion batteries are considered as a promising candidate for large-scale energy storage systems. However, the high flammability of conventional electrolytes may pose serious safety threats and even explosions. Herein, a strategy of constructing a deep eutectic electrolyte is proposed to boost the safety and electrochemical performance of succinonitrile (SN)-based electrolyte. The strong hydrogen bond between S═O of 1,3,2-dioxathiolane-2,2-dioxide (DTD) and the α-H of SN endows the enhanced safety and compatibility of SN with Lewis bases. Meanwhile, the DTD participates in the inner Na sheath and weakens the coordination number of SN. The unique solvation configuration promotes the formation of robust gradient inorganic-rich electrode-electrolyte interphase, and merits stable cycling of half-cells in a wide temperature range, with a capacity retention of 82.8% after 800 cycles (25 °C) and 86.3% after 100 cycles (60 °C). Correspondingly, the full cells deliver tremendous improvement in cycling stability and rate performance.
本质安全型钠离子电池被认为是大规模储能系统的一个有前途的候选者。然而，传统电解质的高易燃性可能会带来严重的安全威胁甚至爆炸。在此，提出了一种构建深共晶电解质的策略，以提高基于丁二腈（SN）的电解质的安全性和电化学性能。1,3,2-二氧杂硫杂环戊烷-2,2-二氧化物（DTD）的S═O与SN的α-H之间的强氢键赋予了SN与路易斯碱增强的安全性和兼容性。同时，DTD参与内部Na鞘层并削弱了SN的配位数。独特的溶剂化构型促进了坚固的梯度富无机电极-电解质界面的形成，并有利于半电池在宽温度范围内稳定循环，在800次循环（25°C）后容量保持率为82.8%，在100次循环（60°C）后容量保持率为86.3%。相应地，全电池在循环稳定性和倍率性能方面有了巨大的提升。
