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Enable High Initial Coulombic Efficiency for Lithium Battery Anode By Ultrathin Polymer Electrolyte Coating

Monday, 14 May 2018
Ballroom 6ABC (Washington State Convention Center)
S. Wang, Y. Gao, B. H. Shen, and W. Tenhaeff (University of Rochester)
The current lithium battery anodes (graphite and graphite-silicon composite) suffer from low initial coulombic efficiency and low charging rate at low temperature. To address these issues, uniform stable solid electrolyte interphase (SEI) and higher ionic transference number are of primary importance. Recent advancements of nanoscale polymer coating open a new way in surface optimization for better performance. Initiated chemical vapor deposition ((iCVD) could achieve uniform nanoscale polymer coating on the porous substrate, which can enable the large-scale coating on battery electrode sheet. Here, ultrathin conformal coating of the Poly(methacrylic acid) (PMAA) polymer is achieved on graphite electrode by iCVD. Then, Ion-exchange is conducted to form the lithium polymer electrolyte. The high ionic transference number of the polymer electrolyte would significantly reduce the ionic polarization at the electrochemical interface, enabling the higher initial coulombic efficiency and power performance at low temperature. The cycling performance was also significantly improved due to the uniform nanoscaled polymer coating.