Liu Xu, Mariani Alessandro, Diemant Thomas, Dong Xu, Su Po-Hua, Passerini Stefano
Helmholtz Institute Ulm (HIU) Electrochemical Energy Storage, Helmholtzstraße 11, 89081, Ulm, Germany.
Karlsruhe Institute of Technology (KIT), P.O. Box 3640, 76021, Karlsruhe, Germany.
Angew Chem Int Ed Engl. 2023 Aug 1;62(31):e202305840. doi: 10.1002/anie.202305840. Epub 2023 Jun 22.
Lithium metal is a promising anode material for next-generation high-energy-density batteries but suffers from low stripping/plating Coulombic efficiency and dendritic growth particularly at sub-zero temperatures. Herein, a poorly-flammable, locally concentrated ionic liquid electrolyte with a wide liquidus range extending well below 0 °C is proposed for low-temperature lithium metal batteries. Its all-anion Li solvation and phase-nano-segregation solution structure are sustained at low temperatures, which, together with a solid electrolyte interphase rich in inorganic compounds, enable dendrite-free operation of lithium metal anodes at -20 °C and 0.5 mA cm , with a Coulombic efficiency of 98.9 %. As a result, lithium metal batteries coupling thin lithium metal anodes (4 mAh cm ) and high-loading LiNi Co Al O cathodes (10 mg cm ) retain 70 % of the initial capacity after 100 cycles at -20 °C. These results, as a proof of concept, demonstrate the applicability of locally concentrated ionic liquid electrolytes for low-temperature lithium metal batteries.
锂金属是下一代高能量密度电池中一种很有前景的负极材料，但存在低脱嵌/沉积库仑效率以及枝晶生长问题，尤其是在零下温度时。在此，我们提出一种难燃的、局部浓缩的离子液体电解质，其宽液程范围能很好地延伸至0°C以下，用于低温锂金属电池。其全阴离子锂溶剂化和相纳米分离溶液结构在低温下得以维持，这与富含无机化合物的固体电解质界面一起，使得锂金属负极在-20°C和0.5 mA cm 时能无枝晶运行，库仑效率为98.9%。结果，耦合薄锂金属负极（4 mAh cm ）和高负载LiNi Co Al O 正极（10 mg cm ）的锂金属电池在-20°C下经过100次循环后仍保留70%的初始容量。这些结果作为概念验证，证明了局部浓缩离子液体电解质在低温锂金属电池中的适用性。
