Ma Yue, Wu Feng, Chen Nan, Ma Yitian, Yang Chao, Shang Yanxin, Liu Hanxiao, Li Li, Chen Renjie
Beijing Key Laboratory of Environmental Science and Engineering, School of Materials Science and Engineering, Beijing Institute of Technology Beijing 100081 China
Advanced Technology Research Institute, Beijing Institute of Technology Jinan 250300 China.
Chem Sci. 2022 Jul 15;13(32):9277-9284. doi: 10.1039/d2sc03313e. eCollection 2022 Aug 17.
Lithium (Li) dendrite growth is a long-standing challenge leading to short cycle life and safety issues in Li metal batteries. Li dendrite growth is kinetically controlled by ion transport, the concentration gradient, and the local electric field. In this study, an internal electric field is generated between the anode and Au-modified separator to eliminate the concentration gradient of Li. The Li-Au alloy is formed during the first cycle of Li plating/stripping, which causes Li deposition on the Au-modified side and lithium anode electrode, reversing the lithium dendrite growth direction. The electrically coupled Li metal electrode and Au-modified film create a uniform electric potential and Li concentration distribution, resulting in reduced concentration polarization and stable Li deposition. As a result, the Au-modified separator improves the lifespan of Li‖Li batteries; the Li‖LiFePO cells show excellent capacity retention (>97.8% after 350 cycles), and Li‖LiNiCoMnO cells deliver 75.1% capacity retention for more than 300 cycles at 1C rate. This strategy offers an efficient approach for commercial application in advanced metallic Li batteries.
锂（Li）枝晶生长是一个长期存在的挑战，会导致锂金属电池的循环寿命缩短和安全问题。锂枝晶生长在动力学上受离子传输、浓度梯度和局部电场控制。在本研究中，在阳极和金改性隔膜之间产生内部电场以消除锂的浓度梯度。在锂电镀/剥离的第一个循环期间形成锂-金合金，这导致锂沉积在金改性侧和锂阳极电极上，从而使锂枝晶生长方向反转。电耦合的锂金属电极和金改性膜产生均匀的电势和锂浓度分布，从而降低浓度极化并实现稳定的锂沉积。结果，金改性隔膜提高了Li‖Li电池的寿命；Li‖LiFePO电池显示出优异的容量保持率（350次循环后>97.8%），并且Li‖LiNiCoMnO电池在1C倍率下超过300次循环可实现75.1%的容量保持率。该策略为先进金属锂电池的商业应用提供了一种有效方法。
