**7. Further research**

Upon addition of plasticizer, some limitations are obtained such as low flash point, slow evaporation, decreases in thermal, electrical and electrochemical stabilities. Low performances, for instance, small working voltage range, narrow electrochemical window, high vapor pressure and poor interfacial stability with lithium electrodes are the disadvantages of plasticized–gel polymer electrolytes (Pandey and Hashmi, 2009). Therefore, ionic liquid will be incorporated into the plasticizer in our further study. Room temperature ionic liquid (RTIL) possesses many attractive properties, such as wider electrochemical potential window (up to 6V), wider decomposition temperature range, non–toxicity and non–volatility as well as non– flammability with low melting point. Other features are better safety performance, relatively high ionic conductivity due to high ion content, and excellent thermal, chemical and electrochemical stabilities (Jiang et al., 2006; Cheng et al., 2007).
