Soft but solid electrolyte extends lithium battery life
S. Himmelstein | July 24, 2020A new battery chemistry combines ceramics and polymers to ward off the formation of dendrites, which undermine the performance and operating life of lithium metal batteries. The dendrite-suppression approach promises high energy density, safer lithium batteries and longer service life in electric vehicles and electric airplanes.
The soft, solid electrolytes developed by researchers from U.S. Lawrence Berkeley National Laboratory and Carnegie Mellon University consist of soft, porous polymers, with nanoscale ceramic particles filling the holes. Manufacturers could produce rolls of the flexible but solid material by sandwiching the electrolyte between the anode and the battery separator. The resulting lithium-electrode sub-assemblies can form drop-in replacements for commonly used graphite anodes and enable continued use of existing assembly lines.
The properties of the soft polymer of intrinsic microporosity were examined in 3D images produced by synchrotron hard X-ray microtomography. Analysis of images of the interface between lithium metal and the electrolyte and of lithium plating and stripping for up to 16 hours at high current showed no evidence of dendrite formation. Early stages of dendritic growth were observed on samples lacking the interface.