Nanostructured Polymer for Ion-Conduction

Lithium-ion batteries are a rapidly-growing industry with widespread applications and superior performance in comparison to other energy storage devices. Block polymer electrolytes show promise in addressing some of the safety and performance limitations of the current liquid electrolytes in lithium-ion batteries. We are interested in designing block polymer electrolytes that can transport lithium ions efficiently to reduce charging times, have sufficient mechanical strength to reduce lithium dendrite growth that can cause short-circuiting between electrodes, and are processible via inexpensive means.

Tapered block polymers are block polymers with interfacial regions that taper from one polymer block to another polymer block (in a well-defined fashion over a well-defined region of the copolymer). These materials are of high interest because the tuning of monomer sequence gives rise to higher ionic conductivities, favorable nanostructures with well-connected ion-conducting pathways, and improved processibilities in comparison to non-tapered analogues while maintaining the desired chemistry and mechanical properties.

Block polymer/homopolymer blends also present an opportunity to improve ionic conductivity and processability. The appropriate combination of polymer molecular weights enables the formation of homopolymer-rich channels that act as “superhighways” for lithium ions.

The precise quantification of structural characteristics of the block polymer electrolytes allows us to identify key parameters that govern the material properties. Experimental techniques such as reflectometry provide nanometer-level resolution to ascertain distributions of monomer segments and ions, while computational modeling suggests mechanistic insights into block polymer assembly. This understanding allows us to advance our material designs efficiently.