Anhydrous proton conduction of 0.6CsHSO4-0.4H4SiW12O40 (CHS-WSiA) composite materials fabricated by dry and wet mechanical ball milling

Abstract

Abstract Anhydrous proton conductive 0.6CsHSO4-0.4H4SiW12O40(CHS-WSiA) composites (in molar ratio) were fabricated by dry and wet mechanical milling. From X-ray diffraction (XRD), the diffraction peak with the highest intensity of WSiA shifted to higher angle from 25.5° to 26.2° in the composites synthesized via dry and wet mechanical ball milling, which indicated that H+ ions in WSiA were partly substituted with Cs+ ions in CHS via ion-exchange reaction to form CHS-WSiA composites. The structural characterizations and conductivity of CHS-WSiA composites fabricated by CHS and WSiA were studied by XRD, thermogravimetry analysis, field emission scanning electron microscopy, and electrochemical impedance analysis (EIS), respectively. The proton conductivities of the composites were largely increased via high chemical interaction between CHS and WSiA, particularly in the low temperature region under a superprotonic phase-transition of CHS. The highest proton conductivity of 9.41 ×10-4 S cm-1 was achieved at 170°C under dry nitrogen atmosphere for 0.6CHS-0.4WSiA composites obtained by wet milling process.