Hefei National Laboratory for Physical Sciences at the Microscale, CAS Key Laboratory of Materials for Energy Conversion, iChEM (Collaborative Innovation Center of Chemistry for Energy Materials), School of Chemistry and Materials Science, University of Science and Technology of China, Hefei, 230026, P. R. China.
Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing, 100871, P. R. China.
Adv Mater. 2018 Aug;30(32):e1800884. doi: 10.1002/adma.201800884. Epub 2018 Jun 19.
There has been a renewed interest in using lithium (Li) metal as an anode material for rechargeable batteries owing to its high theoretical capacity of 3860 mA h g . Despite extensive research, modifications to effectively inhibit Li dendrite growth still result in decreased Li loading and Li utilization. As a result, real capacities are often lower than values expected, if the total mass of the electrode is taken into consideration. Herein, a lightweight yet mechanically robust carbon nanotube (CNT) paper is demonstrated as a freestanding framework to accommodate Li metal with a Li mass fraction of 80.7 wt%. The highly conductive network made of sp2-hybridized carbon effectively inhibits formation of Li dendrites and affords a favorable coulombic efficiency of >97.5%. Moreover, the Li/CNT electrode retains practical areal and gravimetric capacities of 10 mA h cm and 2830 mA h g (vs the mass of electrode), respectively, with 90.9% Li utilization for 1000 cycles at a current density of 10 mA cm . It is demonstrated that the robust and expandable nature is a distinguishing feature of the CNT paper as compared to other 3D scaffolds, and is a key factor that leads to the improved electrochemical performance of the Li/CNT anodes.
由于其高达 3860 mA h g 的理论容量，人们对将金属锂（Li）用作可充电电池的阳极材料重新产生了兴趣。尽管进行了广泛的研究，但对有效抑制 Li 枝晶生长的修改仍会导致 Li 负载和 Li 利用率降低。因此，如果考虑到电极的总质量，实际容量通常会低于预期值。在这里，展示了一种重量轻但机械强度高的碳纳米管（CNT）纸，作为一种独立的框架，可容纳 Li 金属，其 Li 质量分数为 80.7 wt%。由 sp2 杂化碳制成的高导电性网络可有效抑制 Li 枝晶的形成，并提供了超过 97.5%的良好库仑效率。此外，Li/CNT 电极在电流密度为 10 mA cm 时，在 1000 次循环中以 90.9%的 Li 利用率保持了 10 mA h cm 和 2830 mA h g（相对于电极质量）的实用面容量和重量容量。与其他 3D 支架相比，证明了 CNT 纸坚固且可扩展的性质是其区别特征，并且是导致 Li/CNT 阳极电化学性能提高的关键因素。
