Jump to main content
Jump to site search


Silicon hydrogensulfates: solid acids with exceptional 25°C conductivities and possible electrochemical device applications

Abstract

Solid acids as a class are of much interest in areas such as acid catalysis, and exotic protonation chemistries. They include the strongest acids yet identified. A subclass exhibit very high protonic conductivity and its members have been investigated as possible fuel cell electrolytes, as first demonstrated by Haile’s group in 2001 with CsHSO4. These superprotonic plastic crystals bring a “true solid state” alternative to polymer electrolytes, operating at mild temperatures (150-200ºC) without the requirement of humidification. However, they suffer from the narrow operating temperature range, and other problems. Here we describe a new class of solid acids based on silicon, which are of general interest. Its members have extraordinary conductivities, as high as 21.5 mS/cm at room temperature, orders of magnitude above any previous reported case. We discuss possible applications. Although the present electrolytes are not suitable for H2/O2 fuel cell applications due to hydrolizable components, a proof of principle short term fuel cell test is shown to produce a maximum (short circuit) current of 640 mA/cm2 at 87oC despite a low open circuit voltage.

Back to tab navigation
Please wait while Download options loads

Supplementary files

Publication details

The article was received on 20 Dec 2016, accepted on 17 May 2017 and first published on 17 May 2017


Article type: Paper
DOI: 10.1039/C6TA10956J
Citation: J. Mater. Chem. A, 2017, Accepted Manuscript
  •   Request permissions

    Silicon hydrogensulfates: solid acids with exceptional 25°C conductivities and possible electrochemical device applications

    I. Santana Klein, S. Davidowski, J. L. Yarger and C. Angell, J. Mater. Chem. A, 2017, Accepted Manuscript , DOI: 10.1039/C6TA10956J

Search articles by author