Fire-extinguishing organic electrolytes for safe batteries
Fire-extinguishing organic electrolytes for safe batteries
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DOI：
10.1038/s41560-017-0033-8
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发表时间：
2018-01-01
期刊：
影响因子：
56.7
通讯作者：
Yamada, Atsuo
中科院分区：
文献类型：
--
作者：
Wang, Jianhui;Yamada, Yuki;Yamada, Atsuo
严重的安全问题阻碍了锂/钠电池的大规模使用。传统的电解质是高度易燃和挥发性的，这可能会导致灾难性的火灾或爆炸。将阻燃溶剂引入电解质中的努力通常导致电池性能受损，因为这些溶剂不能适当地钝化碳质阳极。在这里，我们报告了一种盐浓度的电解质设计，以解决这一困境，通过自发形成一个强大的无机钝化膜的阳极。我们证明，使用盐和常用的阻燃溶剂（磷酸三甲酯），没有任何添加剂或软粘合剂的浓缩电解质，允许硬碳和石墨阳极稳定的充放电循环超过1,000次循环（超过一年），降解可忽略不计;这种性能与传统的易燃碳酸盐电解质相当或上级。浓缩电解质的不寻常的钝化特性加上其灭火性能有助于开发安全和持久的电池，从而打开了开发更高能量密度电池的限制。
Severe safety concerns are impeding the large-scale employment of lithium/sodium batteries. Conventional electrolytes are highly flammable and volatile, which may cause catastrophic fires or explosions. Efforts to introduce flame-retardant solvents into the electrolytes have generally resulted in compromised battery performance because those solvents do not suitably passivate carbonaceous anodes. Here we report a salt-concentrated electrolyte design to resolve this dilemma via the spontaneous formation of a robust inorganic passivation film on the anode. We demonstrate that a concentrated electrolyte using a salt and a popular flame-retardant solvent (trimethyl phosphate), without any additives or soft binders, allows stable charge-discharge cycling of both hard-carbon and graphite anodes for more than 1,000 cycles (over one year) with negligible degradation; this performance is comparable or superior to that of conventional flammable carbonate electrolytes. The unusual passivation character of the concentrated electrolyte coupled with its fire-extinguishing property contributes to developing safe and long-lasting batteries, unlocking the limit toward development of much higher energy-density batteries.