| Lithium Ion Concentration Dependant Ionic Conductivity and Thermal Properties in Solid Poly(PEGMA-co-acrylonitrile) Electrolytes |
|
Kyung-Chan Kim, Sae-Weon Roh, Sang-Woog Ryu |
|
Department of Engineering Chemistry, Chungbuk National University;Samsung SDI;Department of Engineering Chemistry, Chungbuk National University; |
|
|
| Abstract |
|
The lithium ion concentration dependant ionic conductivity and thermal properties of poly(ethylene glycol) methyl ether methacrylate (PEGMA)/acrylonitrile-based copolymer electrolytes with $LiClO_4$ have been studied by differential scanning calorimetry (DSC), linear sweep voltammetry (LSV) and AC complex impedance measurements. In systems with 11 wt% of acrylonitrile all liquid electrolytes were obtained regardless of lithium ion concentration. Complex impedance measurements with stainless steel electrodes give ambient ionic conductivities $8.1 imes10^{-6}sim1.4 imes10^{-4}S cm^{-1}$. On the other hand, a hard and soft films at ambient temperature were obtained in copolymer electrolyte system consists of 15 wt% acrylonitrile with 6 : 1 and 3 : 1 of [EO] : [Li] ratio, respectively. DSC measurements indicate the crystalline melting temperature of poly(PEGMA) disappeared completely after addition of $LiClO_4$ in this system due to the complex formation between ethylene oxide (EO) unit and lithium salt. As a result, free standing film with room temperature ionic conductivity of $1.7 imes10^{-4}S cm^{-1}$ and high electrochemical stability up to 5.5V was obtained by controlling of acrylonitrile and lithium salt concentration. |
| Key Words:
Polymer electrolyte, Copolymer, Free standing film, Ionic conductivity, Crystalline melting |
|
PDF Links
Full text via DOI
Download Citation
