TY - JOUR
T1 - Immobilization of Anions on Polymer Matrices for Gel Electrolytes with High Conductivity and Stability in Lithium Ion Batteries
AU - Wang, Shih Hong
AU - Lin, Yong Yi
AU - Teng, Chiao Yi
AU - Chen, Yen Ming
AU - Kuo, Ping Lin
AU - Lee, Yuh Lang
AU - Hsieh, Chien Te
AU - Teng, Hsisheng
PY - 2016/6/15
Y1 - 2016/6/15
N2 - 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.
AB - 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.
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U2 - 10.1021/acsami.6b01753
DO - 10.1021/acsami.6b01753
M3 - Article
AN - SCOPUS:84975261075
VL - 8
SP - 14776
EP - 14787
JO - ACS applied materials & interfaces
JF - ACS applied materials & interfaces
SN - 1944-8244
IS - 23
ER -