Polymeric gel electrolytes using a network matrix with carbonyl groups for rechargeable lithium batteries

A novel polymer matrix containing carbonyl groups in its network structure has been examined as the base component of polymeric gel electrolytes for rechargeable lithium batteries. The gel electrolyte was prepared by solidification based on photo-induced radical polymerization of a mixture of ethylmethacrylmethyl carbonate (EMMC) and diethyleneglycol dimethacrylate (DEGDM) that contains LiPF6 as the electrolytic salt with a liquid component of ethylene carbonate (EC) and dimethyl carbonate (DMC). The obtained gel film was flexible and self-standing with proper mechanical strength. The ionic conductivity of the polymeric film was about 1 mS cm−1 at room temperature. The introduction of carbonyl groups to the polymer matrix was effective to hold the liquid component as homogeneous gel phase. The applicability of the present gel system to rechargeable battery was examined by cyclic voltammetry and constant-current polarization of metallic lithium and lithium titanate electrodes.