title: Interconnected hollow carbon nanospheres for stable lithium metal anodes.
abstract: 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 high-capacity 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)) and 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). The 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.
authors: Department of Chemical Engineering, Stanford University, Stanford, California 94305-5025, USA.
authors: Guangyuan
authors: G
authors: Zheng
authors: Department of Materials Science and Engineering, Stanford, California 94305-4034, USA.
authors: Seok Woo
authors: SW
authors: Lee
authors: Department of Materials Science and Engineering, Stanford, California 94305-4034, USA.
authors: Zheng
authors: Z
authors: Liang
authors: Department of Materials Science and Engineering, Stanford, California 94305-4034, USA.
authors: Hyun-Wook
authors: 0000000190741619
authors: HW
authors: Lee
authors: Department of Materials Science and Engineering, Stanford, California 94305-4034, USA.
authors: Kai
authors: K
authors: Yan
authors: Department of Materials Science and Engineering, Stanford, California 94305-4034, USA.
authors: Hongbin
authors: H
authors: Yao
authors: Department of Applied Physics, Stanford, California 94305, USA.
authors: Haotian
authors: H
authors: Wang
authors: Department of Materials Science and Engineering, Stanford, California 94305-4034, USA.
authors: Weiyang
authors: W
authors: Li
authors: Department of Physics, Stanford University, Stanford, California 94305, USA.
authors: Steven
authors: S
authors: Chu
authors: 1] Department of Materials Science and Engineering, Stanford, California 94305-4034, USA [2] Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA.
authors: Yi
authors: Y
authors: Cui