title: Tough germanium nanoparticles under electrochemical cycling.
abstract: Mechanical degradation of the electrode materials during electrochemical cycling remains a serious issue that critically limits the capacity retention and cyclability of rechargeable lithium-ion batteries. Here we report the highly reversible expansion and contraction of germanium nanoparticles under lithiation-delithiation cycling with in situ transmission electron microscopy (TEM). During multiple cycles to the full capacity, the germanium nanoparticles remained robust without any visible cracking despite ∼260% volume changes, in contrast to the size-dependent fracture of silicon nanoparticles upon the first lithiation. The comparative in situ TEM study of fragile silicon nanoparticles suggests that the tough behavior of germanium nanoparticles can be attributed to the weak anisotropy of the lithiation strain at the reaction front. The tough germanium nanoparticles offer substantial potential for the development of durable, high-capacity, and high-rate anodes for advanced lithium-ion batteries.
authors: Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, Pennsylvania 16802, United States.
authors: Wentao
authors: W
authors: Liang
authors: Hui
authors: H
authors: Yang
authors: Feifei
authors: F
authors: Fan
authors: Yang
authors: Y
authors: Liu
authors: Xiao Hua
authors: XH
authors: Liu
authors: Jian Yu
authors: JY
authors: Huang
authors: Ting
authors: T
authors: Zhu
authors: Sulin
authors: S
authors: Zhang
mesh_terms: D004553:Electric Conductivity; D004574:Electromagnetic Fields; D005857:Germanium / Q000737:chemistry* / Q000528:radiation effects; D008422:Materials Testing; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000528:radiation effects; D008839:Microelectrodes
chemical_list: D005857:Germanium