Wang Chao, Liu Ming, Thijs Michel, Ooms Frans G B, Ganapathy Swapna, Wagemaker Marnix
Section Storage of Electrochemical Energy, Radiation Science and Technology, Faculty of Applied Sciences, Delft University of Technology, Delft, Netherlands.
Neutron & Positron Methods for Materials, Radiation Science and Technology, Faculty of Applied Sciences, Delft University of Technology, Delft, Netherlands.
Nat Commun. 2021 Nov 11;12(1):6536. doi: 10.1038/s41467-021-26859-8.
Li metal batteries are being intensively investigated as a means to achieve higher energy density when compared with standard Li-ion batteries. However, the formation of dendritic and mossy Li metal microstructures at the negative electrode during stripping/plating cycles causes electrolyte decomposition and the formation of electronically disconnected Li metal particles. Here we investigate the use of a Cu current collector coated with a high dielectric BaTiO porous scaffold to suppress the electrical field gradients that cause morphological inhomogeneities during Li metal stripping/plating. Applying operando solid-state nuclear magnetic resonance measurements, we demonstrate that the high dielectric BaTiO porous scaffold promotes dense Li deposition, improves the average plating/stripping efficiency and extends the cycling life of the cell compared to both bare Cu and to a low dielectric scaffold material (i.e., AlO). We report electrochemical tests in full anode-free coin cells using a LiNiCoMnO-based positive electrode and a LiPF-based electrolyte to demonstrate the cycling efficiency of the BaTiO-coated Cu electrode.
与标准锂离子电池相比，锂金属电池作为一种实现更高能量密度的手段正受到深入研究。然而，在脱嵌/电镀循环过程中，负极上枝晶状和苔藓状锂金属微结构的形成会导致电解质分解以及形成电子不连续的锂金属颗粒。在此，我们研究了使用涂覆有高介电常数钛酸钡多孔支架的铜集流体，以抑制在锂金属脱嵌/电镀过程中导致形态不均匀的电场梯度。通过进行原位固态核磁共振测量，我们证明，与裸铜以及低介电常数支架材料（即氧化铝）相比，高介电常数钛酸钡多孔支架促进了致密锂沉积，提高了平均电镀/脱嵌效率，并延长了电池的循环寿命。我们报告了在使用基于镍钴锰酸锂的正极和基于六氟磷酸锂的电解质的全无阳极硬币电池中的电化学测试，以证明涂覆有钛酸钡的铜电极的循环效率。
