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Surface State Control of Lithium for Highly Smooth Electrodeposition

用于高度平滑电沉积的锂表面状态控制

基本信息

批准号：
07555575
负责人：
KANAMURA Kiyoshi
金额：
$ 2.75万
依托单位：
KYOTO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1997
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07555575/
关键词：
Lithium metal Surface Potential Atomic force microscopy in situ FTIR HF additives Rechargeable Lithium Battery Surface film Quartz crystal microbalance method 超平滑メッキ非水電解液充放電試験表面被膜表面電位添加剤充放電効率 X線光電子分光法

项目摘要

Lithium metal which has a theoretically highest energy density, cannot be used in practical batteries, because of the dendritic morphology of lithium deposits. In this study, a highly smooth deposition of lithium was realized by a novel surface state control of lithium.(1)When HF or (C_2H_5)_4NF(HF)_4 was added into nonaqueous electrolytes, the dendrite formation was successfully suppressed.(2)In this case, the surface film consisted of a tight bi-layr structure of LiF/Li_2O.(3)The dynamic observation for the surface film formation was carried out by using in situ FTIR measurement.(4)The effect of HF depended on the electrodeposition current and the concentration of HF.(5)The surface film formed during the first deposition was destroyed during the first dissolution process, leading to a direct attachment of electrolyte with lithium metal. The new surface film was formed at the destroyed part during the second charge process.(6)The destroyed surface film was accumulated during discharge and charge cycles. This surface film was so porous that its resistance was very low.(7)However, this surface film prevented a adequate supply of HF to form a tight bi-layr structure of LiF/Li_2O,leading to the formation of lithium dendrite.(8)The nano-distribution of surface potential was measured by using Atomic Force Microscopy and Surface Potential Detection Method. The LiF/Li_2O surface film was highly uniform.

理论上具有最高能量密度的锂金属，由于锂沉积物的枝晶形态，不能用于实际的电池中。在这项研究中，通过一种新的锂表面状态控制，实现了锂的高度光滑沉积。(1)在非水电解质中加入HF或（C_2H_5）_4 - nf (HF)_4，可成功抑制枝晶的形成。(2)在这种情况下，表面膜由LiF/Li_2O的紧密双层结构组成。(3)采用原位FTIR测量对表面成膜过程进行了动态观察。(4) HF的作用取决于电沉积电流和HF浓度。(5)第一次沉积形成的表面膜在第一次溶解过程中被破坏，导致电解液与金属锂直接附着。在二次充电过程中，在损坏部位形成了新的表面膜。(6)在放电和充电循环过程中，破坏的表面膜不断累积。这种表面膜是如此多孔，它的阻力很低。(7)然而，这种表面膜阻止了HF的充足供应，形成LiF/Li_2O的紧密双层结构，导致锂枝晶的形成。(8)采用原子力显微镜和表面电位检测法测定了表面电位的纳米分布。LiF/Li_2O表面膜高度均匀。