title: Immobilization of Anions on Polymer Matrices for Gel Electrolytes with High Conductivity and Stability in Lithium Ion Batteries.
abstract: 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
  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
  TiO2 is nearly 1 order of magnitude higher than that of commercial separator-supported liquid electrolyte (SLE).
  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
  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.
authors.forename: Shih-Hong
authors.initials: SH
authors.lastname: Wang
authors.forename: Yong-Yi
authors.initials: YY
authors.lastname: Lin
authors.forename: Chiao-Yi
authors.initials: CY
authors.lastname: Teng
authors.forename: Yen-Ming
authors.initials: YM
authors.lastname: Chen
authors.forename: Ping-Lin
authors.initials: PL
authors.lastname: Kuo
authors.forename: Yuh-Lang
authors.initials: YL
authors.lastname: Lee
authors.affiliation: Department of Chemical Engineering and Materials Science, Yuan Ze Fuel Cell Center, Yuan Ze University , Taoyuan 32023, Taiwan.
authors.forename: Chien-Te
authors.initials: CT
authors.lastname: Hsieh
authors.forename: Hsisheng
authors.initials: H
authors.lastname: Teng
keywords: gel polymer electrolyte; lithium ion battery; lithium transference number; poly(acrylonitrile); space charge regime