Development of a novel polymer-garnet solid state composite electrolyte incorporating Li-La-Zr-Bi-O and polyethylene oxide
Abstract
Current lithium ion batteries are comprised of organic liquid electrolytes - a mixture of lithium salts and binary solvents such as ethylene carbonate (EC) and dimethyl carbonate (DMC). The main drawbacks of this liquid mixture related to safety are flammability of the organic solvents and chemical instability with the electrode materials. To date, various ceramic and polymer materials have been considered which overcome safety issues. However, a common problem of these solid state materials is that they are not able to provide high ionic conductivity at ambient temperatures. Garnet-type cubic Li7La 3Zr2O12 ceramic material has attracted much interest because of its high ionic conductivity and stability with Li metal. In addition to that, polyethylene oxide (PEO) is known as an ionic conducting polymer and has been extensively investigated. The Li7-xLa3Zr 2-xBixO12 (LLZBO) composition was synthesized by Pechini sol-gel method, incorporating a mixture of dissolved salts into nitric acid. After calcination of the product, a ball milling procedure was developed to reduce particle size and various contents of ceramic, salts and polymer solid composite membranes were formed during the ball milling operation. Different LLZBO, PEO and Li salt contents were examined to obtain the highest ionic conductivity at room temperature and the optimum composition for the composite electrolyte was identified.
Degree
M.S.M.S.E.
Advisors
Youngblood, Purdue University.
Subject Area
Chemistry|Materials science
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