Polyvinyl formal based gel polymer electrolyte prepared using initiator free in-situ thermal polymerization method
发表时间：2015-03-05 11:05
Novel polyvinyl formal (PVFM) based gel polymer electrolytes (GPEs) are developed using an initiator
free thermal polymerization method. The polymerization mechanism during the cross-linking process is
investigated by means of Fourier transform infrared (FTIR) spectroscopy measurements. With the prepared GPEs (containing 2 to 5 wt % PVFM), Li polymer batteries with LiFePO4 as the cathode are
assembled, and the electrochemical properties such as interfacial impedance, electrochemical stability
window and cycling performance are evaluated. The resulting PVFM based GPEs present a better thermal
stability compared with the corresponding conventional liquid electrolyte and an acceptable conductivity of w103 S cm1 at ambient temperatures. Cyclic voltammetric (CV) curves reveal that the electrochemical stability window of PVFM based GPE is 1.5e5V vs. Li/Liþ and wider than that for the
corresponding liquid electrolyte which is 1.8e4.4 V. The discharge capacity of the polymer Li/LiFePO4
battery is 145 mAh g1 over a voltage range of 2.5e4.25 V at 1/10 C rate after 80 cycles with a small
capacity fade.