1] Mechanical, Aerospace and Nuclear Engineering, Rensselaer Polytechnic Institute, 110 8th Street, Troy, New York 12180, USA [2].
Mechanics of Solids and Structures, Brown University, Providence, Rhode Island 02912, USA.
Nat Commun. 2014 Apr 22;5:3710. doi: 10.1038/ncomms4710.
Lithium metal is known to possess a very high theoretical capacity of 3,842 mAh g(-1) in lithium batteries. However, the use of metallic lithium leads to extensive dendritic growth that poses serious safety hazards. Hence, lithium metal has long been replaced by layered lithium metal oxide and phospho-olivine cathodes that offer safer performance over extended cycling, although significantly compromising on the achievable capacities. Here we report the defect-induced plating of metallic lithium within the interior of a porous graphene network. The network acts as a caged entrapment for lithium metal that prevents dendritic growth, facilitating extended cycling of the electrode. The plating of lithium metal within the interior of the porous graphene structure results in very high specific capacities in excess of 850 mAh g(-1). Extended testing for over 1,000 charge/discharge cycles indicates excellent reversibility and coulombic efficiencies above 99%.
金属锂在锂电池中具有非常高的理论容量 3842mAh/g。然而，金属锂的使用会导致严重的安全隐患的枝晶生长。因此，金属锂长期以来一直被层状锂金属氧化物和磷橄榄石阴极所取代，这些阴极在延长循环寿命方面提供了更安全的性能，尽管在可实现的容量方面有很大的妥协。在这里，我们报告了在多孔石墨烯网络内部诱导金属锂电镀。该网络充当金属锂的笼式捕获物，防止枝晶生长，从而实现电极的扩展循环。在多孔石墨烯结构内部电镀金属锂可获得超过 850mAh/g 的超高比容量。超过 1000 次充放电循环的扩展测试表明，其具有优异的可逆性和超过 99%的库仑效率。
