Silicate-based polymer-nanocomposite membranes for polymer electrolyte membrane fuel cells

Advanced nanocomposite membranes for fuel cell applications: a comprehensive review

“…The high proton conductivity of Nafion ® at low temperatures and its lower conductivity at high temperatures have prompted many researchers to investigate its proton conduction mechanism (Mishra et al, 2012). Proton conductivity is a major parameter to evaluate the membrane performance.…”

“…The decomposition profiles of membranes measured by TGA depend on many factors, including heating rate, gas (nitrogen or oxygen) flow rate, and sample preparation technique (Mishra et al, 2012). There are generally three stages in the decomposition process of membranes: (1) the release of free and bound water molecules; (2) the decomposition of functional groups; and (3) the separation of core series of the membrane (Zakaria et al, 2016).…”

“…By modifying the silicate surface using different modifiers phase inconsistency between organic polymer membranes and inorganic silicate could be avoided. In general, silica is synthesized through the hydrolysis and polycondensation of alkoxy silanes in an acidic or basic medium, using different precursors such as alkoxy silanes (like tetraethyl orthosilicate (TEOS)), sodium metasilicate, and fumed silica (Mishra et al, 2012). The hydrophilic nature of silicates helps in developing the proton conductivity of nanocomposite membranes.…”

“…Clay (layered silicates), including montmorillonite and laponite, are one class of the most widely used inorganic fillers for the preparation of polymerclay nanocomposite membranes for PEMFCs owing to high aspect ratio and excellent barrier properties (Mishra et al, 2012). The thickness of the layer is generally around 1 nm, and the lateral dimensions of these layers vary from 30 nm to several µm or larger depending on the particular layered silicate (Laberty-Robert et al, 2011).…”

“…FCs diminish power loses by avoiding the intermediate steps required in similar diesel-powered generators (Mishra et al, 2012). FCs are commonly named and classified based on the nature of the electrolyte used in the cell as follows: proton exchange membrane fuel cell (PEMFC), direct methanol fuel cell (DMFC), phosphoric acid fuel cell (PAFC), molten carbonate fuel cell (MCFC), solid oxide fuel cell (SOFC), alkaline fuel cell (AFC), microbial fuel cell (MFC), and enzymatic fuel cell (EFC), and in general, two main classes can be defined: i) low temperature FCs operating at temperatures lower than 250 ºC (such as proton exchange membrane fuel cells (PEMCs)) and ii) high temperature FCs operating at temperatures ranging from 600 ºC up to 1100 ºC (such as solid oxide fuel cells (SOFCs)) (Laberty-Robert et al, 2011).…”