Recently, advances in simply lowering the freezing point of dilute aqueous electrolytes have somewhat improved the low-temperature performance of aqueous Na-ion batteries (ANIBs), which promote applications in grid-scale energy storage across multiple scenarios. However, the inconsistency between the freezing points of the electrolytes and the stable operating temperature range for most batteries suggests that there are other crucial factors at play. In this work, we redirect our efforts toward elucidating the intricate interfacial aspects by employing diverse electrode types and electrolytes with varying concentrations. Along this line, a “selective interface blocking” mechanism is proposed for battery failure at low temperatures, involving the independent precipitation of ice on the anode side and salt on the cathode side at high potentials, regardless of frozen electrolytes. Our research sheds new light on the intricate relationship between interfaces and low-temperature performance, redefining and systematically constructing the failure mechanism in ANIBs.

中文翻译：

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解读低温下水系钠离子电池的界面失效机制

近年来，简单地降低稀水电解质冰点的进展在一定程度上改善了水钠离子电池（ANIB）的低温性能，从而促进了在多种场景下电网规模储能的应用。然而，大多数电池的电解质冰点和稳定工作温度范围之间的不一致表明还有其他关键因素在起作用。在这项工作中，我们通过采用不同的电极类型和不同浓度的电解质来阐明复杂的界面方面。沿着这个思路，针对低温下的电池失效提出了一种“选择性界面阻断”机制，涉及在高电势下阳极侧的冰和阴极侧的盐的独立沉淀，无论电解质如何冻结。我们的研究为界面与低温性能之间的复杂关系提供了新的线索，重新定义并系统地构建了 ANIB 的失效机制。