法拉第效率
阳极
材料科学
电解质
锂(药物)
纳米技术
阴极
化学工程
碳纤维
电极
硅
锡
复合材料
光电子学
化学
冶金
工程类
复合数
内分泌学
物理化学
医学
作者
Guangyuan Zheng,Seok Woo Lee,Zheng Liang,Hyun‐Wook Lee,Kai Yan,Hong‐Bin Yao,Haotian Wang,Weiyang Li,Steven Chu,Yi Cui
标识
DOI:10.1038/nnano.2014.152
摘要
For future applications in portable electronics, electric vehicles and grid storage, batteries with higher energy storage density than existing lithium ion batteries need to be developed. Recent efforts in this direction have focused on highcapacity electrode materials such as lithium metal, silicon and tin as anodes, and sulphur and oxygen as cathodes. Lithium metal would be the optimal choice as an anode material, because it has the highest specific capacity (3,860 mAh g –1 )a nd the lowest anode potential of all. However, the lithium anode forms dendritic and mossy metal deposits, leading to serious safety concerns and low Coulombic efficiency during charge/discharge cycles. Although advanced characterization techniques have helped shed light on the lithium growth process, effective strategies to improve lithium metal anode cycling remain elusive. Here, we show that coating the lithium metal anode with a monolayer of interconnected amorphous hollow carbon nanospheres helps isolate the lithium metal depositions and facilitates the formation of a stable solid electrolyte interphase. We show that lithium dendrites do not form up to a practical current density of 1 mA cm –2 .T he Coulombic efficiency improves to ∼99% for more than 150 cycles. This is significantly better than the bare unmodified samples, which usually show rapid Coulombic efficiency decay in fewer than 100 cycles. Our results indicate that nanoscale interfacial engineering could be a promising strategy to tackle the intrinsic problems of lithium metal anodes.
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