TY - JOUR

T1 - Reinforcing Germanium Electrode with Polymer Matrix Decoration for Long Cycle Life Rechargeable Lithium Ion Batteries

AU - Sun, Xiaolei

AU - Lu, Xueyi

AU - Huang, Shaozhuan

AU - Xi, Lixia

AU - Liu, Lixang

AU - Liu, Bo

AU - Weng, Qunhong

AU - Zhang, Lin

AU - Schmidt, Oliver G.

N1 - Funding information: This work was financially supported by the German Science Foundation (DFG) under the program “Temporary Position for Principal Investigator”.

PY - 2017

Y1 - 2017

N2 - Germanium is a promising anode material for lithium ion batteries because of its high theoretical specific capacity and low operation voltage. However, a significant challenge in using Ge-based anodes is the large volume variation during cycling that causes pulverization and capacity fade. Despite intense studies in the past decade, unsatisfactory cycling stability of the Ge-based electrodes still impedes their widespread applications. In this study, we demonstrate a high-performance electrode through the synergistic combination of a high-capacity Ge film grown on a three-dimensional current collector and an in situ formed poly(vinylidene fluoride)-hexafluoropropene/SiO 2 protective layer. Specifically, the polymer matrix is in continuous contact with the surface of the Ge shell, which provides improved mechanical and ionic transport properties. As a highlight, we present impressive cycling stability over 3000 cycles at 1 C rate with a capacity retention as high as 95.7%. Furthermore, the LiCoO 2-Ge full battery operates at an average voltage of 3.3 V at 0.5 C and maintains good electrochemical performance, suggesting great potential for applications in energy storage and conversion devices.

AB - Germanium is a promising anode material for lithium ion batteries because of its high theoretical specific capacity and low operation voltage. However, a significant challenge in using Ge-based anodes is the large volume variation during cycling that causes pulverization and capacity fade. Despite intense studies in the past decade, unsatisfactory cycling stability of the Ge-based electrodes still impedes their widespread applications. In this study, we demonstrate a high-performance electrode through the synergistic combination of a high-capacity Ge film grown on a three-dimensional current collector and an in situ formed poly(vinylidene fluoride)-hexafluoropropene/SiO 2 protective layer. Specifically, the polymer matrix is in continuous contact with the surface of the Ge shell, which provides improved mechanical and ionic transport properties. As a highlight, we present impressive cycling stability over 3000 cycles at 1 C rate with a capacity retention as high as 95.7%. Furthermore, the LiCoO 2-Ge full battery operates at an average voltage of 3.3 V at 0.5 C and maintains good electrochemical performance, suggesting great potential for applications in energy storage and conversion devices.

KW - amorphous Ge anode

KW - full cell

KW - high electrochemical performance

KW - lithium storage

KW - PVDF-HFP/SiO functional coating

UR - http://www.scopus.com/inward/record.url?scp=85033446586&partnerID=8YFLogxK

U2 - 10.1021/acsami.7b12228

DO - 10.1021/acsami.7b12228

M3 - Article

VL - 9

SP - 38556

EP - 38566

JO - ACS Applied Materials & Interfaces

JF - ACS Applied Materials & Interfaces

SN - 1944-8244

IS - 44

ER -