New high temperature proton conducting polymer electrolyte for sustainable energy conversion applications

Research area: Polymer science and nanomaterials
Supervisors: Prof Naba Dutta, Prof Namita Roy Choudhury, Dr Anita Hill (CSIRO-Process Science and Engineering) and Prof Steven Holdcroft (Simon Fraser University, Canada)

Aim: Development of a new class of high temperature proton conducting membrane from unique polymer based nanomaterials.

Description: The fuel cell represents a fundamentally promising but different way of generating electrical power from a variety of fuels, which converts the chemical energy of a fuel and oxidant directly into electrical power. The key features of a fuel cell are; its high-energy conversion efficiency, cleanliness and fuel flexibility.

The polymeric proton exchange membrane (PEM) is one of the key components in solid polymer electrolyte fuel cell (PEFC). PEM fuel cells offer high power density, possess no corrosive liquids, are relatively simple, and operate at relatively low operating temperatures (50oC-95oC) and pressure (<5 atm). In a typical PEM fuel cell, a polymeric membrane provides the ionic path between the anode and the cathode of the galvanic cell and serves to separate the two-reactant gases.

The primary demands on the PEMs are: high proton conductivity, zero electronic conductivity, low fuel and gas permeability, dimensional stability, good mechanical strength, resistance to dehydration at high temperature, chemical stability towards oxidation, reduction and hydrolysis; and low cost. Conventional proton conducting polymers are based on hydrated ionomers with sulfonic acid groups in their protonated form. A profound drawback of current PEM- common to all aqueous-based proton exchange membranes, in general- is their inability to operate at temperature higher than 100oC, or under lower humidity, for extended periods. 

This project will address the critical issue of operating proton exchange membrane fuel cells (PEMFC) at above 100oC - a temperature desirable for several technical reasons, but destructive to current PEM and catalyst components. We will use the concept of incorporating inorganic nanoparticles/nanonetworks in mesophase separated polymer phase in order to lower the vapour pressure of water in the membrane.

The principal aim of the project is to produce a family of self-humidifying composite membranes containing various phospohosilicate networks organized in the supramolecular assembly of fluoro/nonfluro block ionomers. Novel solid polymer electrolyte systems comprising fluoropolymer and non-fluoropolymer segments such as sulfonated poly (vinylidene difluoride-block-polystyrene copolymers will be developed. Advanced sol-gel methodology will be developed to prepare hybrids that can be cast as membranes, and incorporated into gas diffusion electrodes, so as to prepare functional proton conducting polymers that operate in fuel cells, operating at temperatures > 100oC/relatively low (well below 100%) relative humidity.

The other specific aims are: (i) control and manipulate the morphology of the ionic block copolymer and inorganic networks, and correlate it with proton conductivity, (ii) devise methodology for investigating the electrochemistry of novel organic/ phosphosilicate hybrids, (iii) investigate proton conductivity at elevated temperature and reduced humidity, (iv) develop methodology for evaluating the state of water in the membrane and its retention at elevated temperature, (v) develop methodology to prepare membrane electrode assembly. The project will also examine the novel materials - mass transport properties on fuel cell, power density and efficiency, analysis of Membranes as Solid Polymer Electrolytes, Proton Conductivity, electrochemical characterization of membranes in contact with catalyst layers, loss of cell voltage under the influence of current load, etc.

This proposal represents a comprehensive interdisciplinary research involving inorganic modification of novel polymers and synthesis of organic-inorganic hybrid, their processing, and a range of novel characterization methods to establish microstructure-morphology-electrochemical property relationship. The researchers will have the opportunity to carry out research in different national and international laboratories.

Collaboration:  This is a collaborative project and the research methodology will primarily cover investigations carried out at the IWRI, UniSA; CSIRO- Manufacturing and Infrastructure Technology and Simon Fraser University, Canada 

Funding: A grant application to the Australian Research Council is currently being assessed. If successful, this grant will support two IWRI fully funded scholarships. International students should also apply for an International Postgraduate Research Scholarship (IPRS) and a UniSA President's Scholarship (UPS).

Australian students should also apply for an Australian Postgraduate Award (APA) and a UniSA Australian Postgraduate Research Award (USAPRA). Project maintenance costs will be met from internal funding.

Areas of study and research

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