Three-dimensional ordered macroporous Cu current collector for lithium metal anode: Uniform nucleation by seed crystal
Three-dimensional ordered macroporous Cu current collector for lithium metal anode: Uniform nucleation by seed crystal
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用于锂金属负极的三维有序大孔铜集流体：籽晶均匀成核
DOI：
10.1016/j.jpowsour.2018.09.083
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发表时间：
2018-11-01
影响因子：
9.2
通讯作者：
Deng, Yida
中科院分区：
文献类型：
--
作者：
Tang, Yiping;Shen, Kang;Deng, Yida
锂金属阳极因其极高的比容量、低密度和低还原电位而被视为“圣杯”。然而，锂枝晶的生长降低了库仑效率，同时引发了安全事故。本文采用胶体模板法结合铜电沉积法制备了一种设计合理的三维有序大孔Cu作为电化学性能优异的锂金属阳极的集流剂。该新型多孔Cu/Li阳极孔径为450 nm，在0.2 mA/cm(2)下稳定运行750 h，锂电镀/剥离过电位小（< 30 mV）， 120次循环库仑效率高达93.3%。大比表面积的三维有序大孔结构降低了局部电流密度，提高了电化学反应动力学，有利于孔隙内锂的沉积。特别是外孔弧区的Li层为后续的Li沉积提供了种子晶，使Li均匀成核，有效地抑制了枝晶。
Lithium metal anode is regarded as the "holy grail' due to its extremely high specific capacity, low density and low reduction potential. However, Li dendrite growth reduces coulombic efficiency and causes safety accidents synchronously. In this paper, a rational designed three-dimensional ordered macroporous Cu is used as current collector for Li metal anode with excellent electrochemical performance, which is prepared by colloidal template method combined with copper electrodeposition. The novel porous Cu/Li anode with the pore size of 450 nm can stably run for 750 h at 0.2 mA/cm(2) with a small Li electroplating/stripping overpotential (< 30 mV), and it exhibits a high coulombic efficiency of 93.3% over 120 cycles. The three-dimensional ordered macroporous structure with large specific surface area results in lower local current density and enhances electrochemical reaction kinetics, and benefits Li deposition inside pores. Especially, the Li layer on the arc area of outer pores acts as seed crystal for the subsequent Li deposition, which leads to Li uniform nucleation and dendrite suppression effectively.