Department of physics & Tsinghua-Foxconn Nanotechnology Research Center, Tsinghua University, Beijing 100084, P.R. China.
Nanoscale. 2016 Jun 7;8(21):11161-7. doi: 10.1039/c6nr00465b. Epub 2016 May 16.
Lithium (Li) metal is one of the most promising candidates as an anode for the next-generation energy storage systems because of its high specific capacity and lowest negative electrochemical potential. But the growth of Li dendrites limits the application of the Li metal battery. In this work, a type of modified Li metal battery with a carbon nanotube (CNT) buffer layer inserted between the separator and the Li metal electrode was reported. The electrochemical results show that the modified batteries have a much better rate capability and cycling performance than the conventional Li metal batteries. The mechanism study by electrochemical impedance spectroscopy reveals that the modified battery has a smaller charge transfer resistance and larger Li ion diffusion coefficient during the deposition process on the Li electrode than the conventional Li metal batteries. Symmetric battery tests show that the interfacial behavior of the Li metal electrode with the buffer layer is more stable than the naked Li metal electrode. The morphological characterization of the CNT buffer layer and Li metal lamina reveals that the CNT buffer layer has restrained the growth of Li dendrites. The CNT buffer layer has great potential to solve the safety problem of the Li metal battery.
锂（Li）金属是下一代储能系统中最有前途的阳极候选材料之一，因为它具有高比容量和最低的负电化学电势。但是，Li 枝晶的生长限制了 Li 金属电池的应用。在这项工作中，报道了一种在隔膜和 Li 金属电极之间插入碳纳米管（CNT）缓冲层的改性 Li 金属电池。电化学结果表明，改性电池的倍率性能和循环性能均优于传统 Li 金属电池。通过电化学阻抗谱的机理研究表明，在 Li 电极上沉积过程中，改性电池的电荷转移电阻较小，Li 离子扩散系数较大，而传统 Li 金属电池则较小。对称电池测试表明，带有缓冲层的 Li 金属电极的界面行为比裸露的 Li 金属电极更稳定。对 CNT 缓冲层和 Li 金属箔的形态表征表明，CNT 缓冲层抑制了 Li 枝晶的生长。CNT 缓冲层具有解决 Li 金属电池安全问题的巨大潜力。
