Ionic Liquid-Based Polymer Electrolytes via Surfactant-Assisted Polymerization at the Plasma-Liquid Interface.
We first report an innovative method, which we refer to as interfacial liquid plasma polymerization, to chemically cross-link ionic liquids (ILs). By this method, a series of all-solid state, free-standing polymer electrolytes is successfully fabricated where ILs are used as building blocks and ethylene oxide-based surfactants are employed as an assisted-cross-linking agent. The thickness of the films is controlled by the plasma exposure time or the ratio of surfactant to ILs. The chemical structure and properties of the polymer electrolyte are characterized by scanning electron microscopy (SEM), Fourier transformation infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR) spectroscopy, X-ray photoelectron spectroscopy (XPS), differential scanning calorimetry (DSC), and electrochemical impedance spectroscopy (EIS). Importantly, the underlying polymerization mechanism of the cross-linked IL-based polymer electrolyte is studied to show that fluoroborate or halide anions of ILs together with the aid of a small amount of surfactants having ethylene oxide groups are necessary to form cross-linked network structures of the polymer electrolyte. The ionic conductivity of the obtained polymer electrolyte is 2.28 × 10(-3) S·cm(-1), which is a relatively high value for solid polymer electrolytes synthesized at room temperature. This study can serve as a cornerstone for developing all-solid state polymer electrolytes with promising properties for next-generation electrochemical devices.
Department of Chemical Engineering and Applied Chemistry, Chungnam National University , 220 Gung-Dong, Yuseong-Gu, Daejeon 305-764, Republic of Korea.
Quoc Chinh
QC
Tran
Department of Chemical Engineering and Applied Chemistry, Chungnam National University , 220 Gung-Dong, Yuseong-Gu, Daejeon 305-764, Republic of Korea.|Institute of Research and Development, Duy Tan University , R.809, K7/25 Quang Trung, Da Nang 550000, Viet Nam.
Van-Tien
VT
Bui
Department of Chemical Engineering and Applied Chemistry, Chungnam National University , 220 Gung-Dong, Yuseong-Gu, Daejeon 305-764, Republic of Korea.
Van-Duong
VD
Dao
Energy Storage Research Center, Korea Institute of Science and Technology , P.O. Box 131, Cheongryang, Seoul 130-650, Republic of Korea.
Joong-Kee
JK
Lee
Department of Chemical Engineering and Applied Chemistry, Chungnam National University , 220 Gung-Dong, Yuseong-Gu, Daejeon 305-764, Republic of Korea.
Ho-Suk
HS
Choi
Triton X100; ion conductivity; ionic liquid; liquid plasma; polymerization; surfactant