Aqueous Na‐ion batteries may offer a solution to the cost and safety issues of high‐energy batteries. However, substantial challenges remain in the development of electrode materials and electrolytes enabling high performance and long cycle life. Herein, we report the characterization of a symmetric Na‐ion battery with a NASICON‐type Na₂VTi(PO₄)₃ electrode material in conventional aqueous and “water‐in‐salt” electrolytes. Extremely stable cycling performance for 1000 cycles at a high rate (20 C) is found with the highly concentrated aqueous electrolytes owing to the formation of a resistive but protective interphase between the electrode and electrolyte. These results provide important insight for the development of aqueous Na‐ion batteries with stable long‐term cycling performance for large‐scale energy storage.

中文翻译：

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迈向高性能钠离子电池水溶液：使用浓缩电解质稳定NASICON型Na2VTi（PO4）3的固/液界面

钠离子水电池可为高能电池的成本和安全性问题提供解决方案。然而，在电极材料和电解质的开发中仍然存在重大挑战，以实现高性能和长循环寿命。本文中，我们报告了具有NASICON型Na ₂ VTi（PO ₄）₃的对称Na离子电池的表征常规水性和“盐分水”电解质中的电极材料。由于在电极和电解质之间形成了电阻性但保护性的中间相，因此在高浓度的水性电解质中，发现了在高速率（20摄氏度）下1000次循环极其稳定的循环性能。这些结果为开发具有稳定长期循环性能的大型Na-ion水性电池提供了重要的见识。