Preparation and Application of Nano-composite Poly(vinyl alcohol) Gel Electrolyte in Electrochemical Capacitor

A nano-composite polymer gel electrolyte was prepared using titanium oxide nanowire,poly(vinyl alcohol)(PVA),lithium salt and organic solvent N-methyl-2-pyrrolidone(NMP).The obtained electrolyte has the potential for application in electrochemical capacitor,the PVA in it is in an amorphous state.The ionic conductivities of electrolytes increased after addition of the nanowire,and the electrolyte with 3%(ω) of nanowire exhibited the highest ionic conductivity of 3.2 mS/cm at 20℃,as measured by electrochemical impedance spectroscopy.The temperature dependence of the conductivity was found to be in agreement with the Arrhenius equation.Functioning as separator and electrolyte,this nano-composite PVA gel electrolyte was used to assemble the electrochemical capacitor with active carbon film as electrodes.The compositing of nanowire may extend the life of electrochemical capacitors as they keep more than 90% of their capacitance after 5000 cycles of charging and discharging.