北京大学庞全全研究团队报道了调节全天候钠离子电池的电解质和相间化学。相关研究成果发表在2024年3月12日出版的《德国应用化学》。

钠离子电池（SIBs）为下一代电网规模的储能提供了一条很有前途的途径。然而，由于电解质导电性差和极端温度下电极界面不稳定，实现所有气候SIBs在宽温度范围内运行仍然是一个挑战。

该文中，研究人员提出了一种全面平衡的电解质，通过将碳酸盐与低冰点和低极性的丙酸乙酯溶剂配对，可以在零度以下温度增强离子扩散和Na⁺-去溶剂化动力学。此外，电解质利用基于硼酸盐和腈的组合添加剂策略，来促进均匀且富含无机物的电极界面，确保在45°C至60°C的宽温度范围内具有优异的倍率性能和循环稳定性。

值得注意的是，Na||磷酸钒钠电池在25°C下以2 C的高倍率提供105 mA h g^-1的显著容量。此外，电池在宽温度范围内表现出优异的循环稳定性，在60°C的3000次循环中保持84.7%的高容量保持率，在25°C的500次循环中维持95.1%的高容量维持率。

该项研究强调了电解质和相间工程用于实现SIBs在不同和极端气候环境下，最佳运行方面的关键作用。

附：英文原文

Title: Tuning the Electrolyte and Interphasial Chemistry for All-Climate Sodium-ion Batteries

Author: Mengxue He, Lujun Zhu, Guo Ye, Yun An, Xufeng Hong, Yue Ma, Zhitong Xiao, Yongfeng Jia, Quanquan Pang

Issue&Volume: 2024-03-12

Abstract: Sodium-ion batteries (SIBs) present a promising avenue for next-generation grid-scale energy storage. However, realizing all-climate SIBs operating across a wide temperature range remains a challenge due to the poor electrolyte conductivity and instable electrode interphases at extreme temperatures. Here, we propose a comprehensively balanced electrolyte by pairing carbonates with a low-freezing-point and low-polarity ethyl propionate solvent which enhances ion diffusion and Na+-desolvation kinetics at sub-zero temperatures. Furthermore, the electrolyte leverages a combinatorial borate- and nitrile-based additive strategy to facilitate uniform and inorganic-rich electrode interphases, ensuring excellent rate performance and cycle stability over a wide temperature range from 45 °C to 60 °C. Notably, the Na||sodium vanadyl phosphate cell delivers a remarkable capacity of 105 mA h g1 with a high rate of 2 C at 25 °C. In addition, the cells exhibit excellent cycling stability over a wide temperature range, maintaining a high capacity retention of 84.7% over 3,000 cycles at 60 °C and of 95.1% at 25 °C over 500 cycles. This study highlights the critical role of electrolyte and interphase engineering for enabling SIBs that function optimally under diverse and extreme climatic environments.

DOI: 10.1002/anie.202401051

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202401051