Performance of Nanostructured Polymer Electrolytes in Li Batteries

Batteries that employ Li anodes for high energy density applications suffer from failures due to side reactions and dendrite growth on the Li electrodes. A recent theory by Newman and Monroe (2005) shows that dendrite formation can be prevented if the shear modulus of the electrolyte can be increased by several orders of magnitude without a concomitant decrease in conductivity. The nanostructured polymer electrolyte (PE) in our study has a modulus of a glassy polymer. AC impedance measurements on Li/PE/Li systems show that the PE has high ionic conductivity. We present experimental data on the performance of a novel nanostructured dry PE in a Li/PE/Li battery. We report the DC cycling measurements, interfacial resistance measurements, and dendrite growth characteristics in Li/PE/Li cells. The performance of the nanostructured PE is compared with that of PE based on the homopolymer poly(ethylene oxide), which is a benchmark for dry polymer electrolytes.