Synthesis and properties of gel polymer electrolyte membranes based on novel comb-like methyl methacrylate copolymers
writer：Yang LL, Ma XY, and Guo NN
keywords：Comb-like copolymer, Gel polymer electrolyte Ionic conductivity, Lithium ion battery, VTF behavior
source：期刊
specific source：Journal of Membrane Science, 2010,349(1-2), pp279-286
Issue time：2010年
Based on the principle of molecular design,
three comb-like methyl methacrylate copolymer matrixes for gel polymer
electrolyte (GPE) were designed and synthesized by reacting methyl
methacrylate-maleic anhydride copolymer (P(MMA-MAh)) with poly(ethylene glycol)
monomethyl ether (PEGME) of different molecular weight (350, 600, and 750)
respectively. The structures of comb-like polymers were characterized by
Fourier transform infrared (FTIR) and 1H-nuclear magnetic resonance (1HNMR), and
their thermal properties were investigated with differential scanning
calorimetry (DSC) and thermogravimetric analysis (TGA). The membranes of
P(MMA-MAh) copolymer and comb-like copolymer based polymer electrolytes, plasticized
with propylene carbonate (PC) and LiClO4as salt, have been prepared by solution
casting technique respectively. And AC impedance was used to characterize the
ion conductivity of GPE systems. Compared with P(MMA-MAh)
copolymer, introducing the flexible ether chain segments can reduce the resistance
of ion transport in polymer matrix and improve the mobility of electroactive
ions in the GPE systems. With the increase in side chain length of copolymers,
ionic conductivity of GPEs is improved dramatically. The highest conductivity
observed in MMA/MAh-g-PEGME600 GPE system (matrix content: 45 wt%) is 1.22×10 ?3S/cm
at 60?C. And temperature dependence of GPE membranes could be described by
Vogel–Tamman–Fulcher (VTF) behavior. TGA curves showed that these gel polymer
electrolyte membranes possessed favorable thermal stability for lithium ion
battery use.