When 3:30 PM - 5:00 PM Oct 24, 2014
Where 1670 Beyster Building
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Keeping up with the increasing demands for electrical vehicle energy storage: Ceramic electrolytes enabling beyond Li-ion batteries


Jeff Sakamoto
University of Michigan, Department of Mechanical Engineering

The interest in vehicle electrification and electrical grid storage is unprecedented. Several automotive manufacturers are producing, or planning to produce, hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and fully (or battery) electric vehicles (BEVs). Li-ion battery technology is the current leading candidate to meet the near and medium-term needs for electric vehicles. However, while progress has been made in the last decade, widespread adoption of electric vehicles will require cheaper, safer, and higher performance battery technology.

 

Whereas the primary strategy for improving performance has focused on electrode materials, the development of new electrolytes has been overlooked as a means to advance electrochemical energy storage. This work explores the development of a new superionic conducting oxide with the nominal formulation Li7La3Zr2O12 (LLZO) mimicking the garnet mineral structure. LLZO exhibits the novel combination of high ionic conductivity (1mS/cm at 298 K; higher than state-of-the-art liquid membrane technology), chemical stability against metallic lithium, and sufficient shear modulus (61 GPa) to suppress lithium dendrite penetration. These materials attributes could enable the first bulk-scale, solid-electrolyte membrane technology for use in non-flammable solid-state and Li-sulfur batteries, as well as Li-air semi-fuel cells.

 

The research addresses both fundamental and applied aspects of LLZO. The fundamental materials research investigates the origin of superionic conductivity, crystallographic phase stability, synthesis and densification phenomena, and mechanical property analysis. The applied research is centered upon a relatively new area of research studying the interactions between LLZO and battery electrodes such as molten or solid Li and Sulfur, or conventional insertion/intercalation electrodes. Solid-state electrolytes are at the frontier of electrochemical energy storage and are justifiably capable of generating significant engineering research and development opportunities in the coming decades.