∥Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, United States.
Nano Lett. 2015 May 13;15(5):2910-6. doi: 10.1021/nl5046318. Epub 2015 Apr 9.
Lithium metal is one of the most promising candidates as an anode material for next-generation energy storage systems due to its highest specific capacity (3860 mAh/g) and lowest redox potential of all. The uncontrolled lithium dendrite growth that causes a poor cycling performance and serious safety hazards, however, presents a significant challenge for the realization of lithium metal-based batteries. Here, we demonstrate a novel electrode design by placing a three-dimensional (3D) oxidized polyacrylonitrile nanofiber network on top of the current collector. The polymer fiber with polar surface functional groups could guide the lithium ions to form uniform lithium metal deposits confined on the polymer fiber surface and in the 3D polymer layer. We showed stable cycling of lithium metal anode with an average Coulombic efficiency of 97.4% over 120 cycles in ether-based electrolyte at a current density of 3 mA/cm(2) for a total of 1 mAh/cm(2) of lithium.
金属锂因其最高的比容量(3860 mAh/g)和最低的氧化还原电位,是下一代储能系统中最有前途的阳极材料之一。然而,不受控制的锂枝晶生长导致循环性能差和严重的安全隐患,这对实现基于金属锂的电池提出了重大挑战。在这里,我们通过在集流器上放置一个三维(3D)氧化聚丙烯腈纳米纤维网络来展示一种新型的电极设计。具有极性表面官能团的聚合物纤维可以引导锂离子形成均匀的锂金属沉积物,这些沉积物被限制在聚合物纤维表面和 3D 聚合物层内。我们在电流密度为 3 mA/cm(2)的醚基电解质中展示了稳定的锂金属阳极循环,在 1 mAh/cm(2)的总锂容量下,经过 120 次循环,平均库仑效率为 97.4%。