(23c) Microstructured Block Copolymer Membranes for Lithium Batteries and Ethanol Separation

Authors: 
Balsara, N. P., University of California, Berkeley


Nanostructured block copolymers enable the design of membranes with optimized transporting channels for a variety of applications.  This presentation addresses the use of these membranse to transport lithium ions in an all solid lithium battery and to separate ethanol from a dilute aqueous stream.  Previous studies of electrolytes showed an inverse correlation between ionic conductivity and shear modulus: increasing conductivity invariably resulted in a decrease in the shear modulus.  Similarly, previous studies of alcohol-selective membranes showed an inverse correlation between alcohol separation factor (ratio of alcohol concentration in the exiting stream to that of the incoming stream) and total flux: increasing the separation factor invariably resulted in a decrease in total flux.  Block copolymer membranes do not show these inverse correlations.  Practical implications of our discoveries for enabling electric vehicles and bioethanol will be discussed.  A large fraction of energy and materials that we use today are derived from industries that consume non-renewable resources.  The two projects described here may enable a gradual transition toward to a more sustainable approach.