Immobilization of Anions on Polymer Matrices for Gel Electrolytes with High Conductivity and Stability in Lithium Ion Batteries

Shih Hong Wang, Yong Yi Lin, Chiao Yi Teng, Yen Ming Chen, Ping-Lin Kuo, Yuh-Lang Lee, Chien Te Hsieh, Hsisheng Teng

研究成果: Article

30 引文 斯高帕斯(Scopus)

摘要

This study reports on a high ionic-conductivity gel polymer electrolyte (GPE), which is supported by a TiO2 nanoparticle-decorated polymer framework comprising poly(acrylonitrile-co-vinyl acetate) blended with poly(methyl methacrylate), i.e., PAVM:TiO2. High conductivity GPE-PAVM:TiO2 is achieved by causing the PAVM:TiO2 polymer framework to swell in 1 M LiPF6 in carbonate solvent. Raman analysis results demonstrate that the poly(acrylonitrile) (PAN) segments and TiO2 nanoparticles strongly adsorb PF6- anions, thereby generating 3D percolative space-charge pathways surrounding the polymer framework for Li+-ion transport. The ionic conductivity of GPE-PAVM:TiO2 is nearly 1 order of magnitude higher than that of commercial separator-supported liquid electrolyte (SLE). GPE-PAVM:TiO2 has a high Li+ transference number (0.7), indicating that most of the PF6- anions are stationary, which suppresses PF6- decomposition and substantially enlarges the voltage that can be applied to GPE-PAVM:TiO2 (to 6.5 V vs Li/Li+). Immobilization of PF6- anions also leads to the formation of stable solid-electrolyte interface (SEI) layers in a full-cell graphite|electrolyte|LiFePO4 battery, which exhibits low SEI and overall resistances. The graphite|electrolyte|LiFePO4 battery delivers high capacity of 84 mAh g-1 even at 20 C and presents 90% and 71% capacity retention after 100 and 1000 charge-discharge cycles, respectively. This study demonstrates a GPE architecture comprising 3D space charge pathways for Li+ ions and suppresses anion decomposition to improve the stability and lifespan of the resulting LIBs.

原文English
頁(從 - 到)14776-14787
頁數12
期刊ACS Applied Materials and Interfaces
8
發行號23
DOIs
出版狀態Published - 2016 六月 15

    指紋

All Science Journal Classification (ASJC) codes

  • Materials Science(all)

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