The controllable method of preparation results in a material that has uniformly excellent mechanical and ion transport properties that appear to be unaffected by the cross-linking density. This allows density to be varied to suit the application. The cross-linked materials achieve much higher lithium ion conductivities than other cross-linked polymers (10-5 S/cm at ambient temperatures) and yet also inhibit dendrite growth due to the mechanical properties. The side chains of the comb-branched structures are long enough to allow for maximum segmental motion so that the polymer can effectively penetrate between the electrode particles and adhere to electrode surfaces while maintaining the amorphous nature that facilitates high ion mobility. This overcomes many of the problems involved in the preparation of good composite electrode structures.
The capabilities, materials, and principles used for developing these polymer electrolytes for lithium batteries can be adapted to develop polymer films for fuel cells and electrochromic windows. Kerr’s group is investigating the use of new proton solvating functions on comb branch polyether polyelectrolyte materials to provide water-free membranes that can operate at high temperatures for fuel cells.
Applications and Industries
- Lithium metal polymer and lithium polymer batteries
- PEM fuel cells
- Electrochromic windows
- High lithium ion conductivity (10-5 S/cm at ambient temperatures)
- No concentration polarization, i.e. the transference number is one
- Clean grafting and cross-linking chemistry leaves no reactive residues
- Materials have uniform, reproducible mechanical properties and electrochemical stability
- Polymer backbone and cross-link density and flexibility may be adapted to tune the transport and mechanical properties
- Innovative solution to lithium mobility problems promises even higher conductivity
- Easy preparation