Understanding Dendrite Abatement in Reaction-Engineered Convection Battery

University Of Missouri-Columbia, Columbia MO

Investigators

Abstract

0940720 Suppes This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). This is a proof of concept with fundamental investigation on a "convection battery" that has inherent design features allowing it to immediately overcome the following barriers to lithium batteries: * Dendrite and Geometry-Based Failure -Large distances and pipes (versus a thin polymer or glass fiber separator) separate electrodes in the convection battery creating expanses far too great for this type of short-circuit mode of failure. * Battery Exotherm - The oxidizing and reducing substrates are in separate vessels where exotherms are limited by the amount of electrolyte in the vessel. * Battery Costs - Separators in traditional spiral-wound batteries are not used in the convection battery which saves on weight, materials, and processing costs (not for convection batteries). * Heat Removal - Heat removal in the convection battery is easy through the incorporation of a radiator in the electrolyte circulation loop. Rather than relying on diffusion for the transport of ions from on electrode to another, the convection battery uses a pump to convectively flow electrolyte through a non-conductive (no free electron flow) pipe network and packed bed electrodes. This design is not practical for small batteries (e.g. 0.1 kWh); however, at sizes above 1 kWh the flow batteries will cost less (and weigh less) than traditional batteries. The pumping energy is minimal, expected to be about 5% of the pumping cost of a radiator pump on a typical automobile. The four tasks of this project will proceed as follows: * Proof of Concept * Lithium Dispersion Studies * Insight Studies and Alternative Chemistries The PI's group has demonstrated an expertise in fabricating the carbon packing and active components in preliminary studies. The unknowns for the convection battery design include the degree of capacity fade from SEI and dendrite fracturing losses, new failure modes that might replace the four barriers overcome by this design, and the manner in which the design degrees of freedom (carbon properties, lithium to carbon ratio on anode, flow rate of electrolyte, particle sizes, and operation mode) can achieve desired performance. These will be investigated with an agenda to better understand dendrite formation and SEI formation as well as how to control these phenomena. Intellectual Merit - The convection battery is a novel/innovative and high impact approach for energy storage that is based on reaction engineering to understand and overcome barriers to typical batteries. Advancing of knowledge will occur because it creates new and improved methods to study and overcome key performance limitations related to dendrite formation and solid-electrolyte interface layer (SEI) formation. The Task 2 view cells will allow the following of dendrite formation along with new degrees of freedom such as flow rate, concentration of electrolyte, and flow direction/reversal to provide an improved understanding of dendrite and SEI formation and to develop methods to overcome these barriers. The research team brings expertise in packed-bed catalysis along with a track record of success from the previous NSF-PFI award on carbon production. Broader Impact - Convection batteries and solutions to dendrite and SEI problems will lead to improved energy storage technology with impact on applications for PHEV vehicles and electric grid energy storage. The social benefits of advances in this area would be in the creation of a new, stable, and competitive manufacturing industry in the U.S. The laboratories of PI actively recruit and foster undergraduate researchers including minorities and females who are encouraged to pursue graduate degrees-in total these labs have about 8 undergraduate researchers. The undergraduate research program is a key part of the chemical engineering program and the equipment and resources of this effort will enhance that infrastructure. The results of this research will be published in engineering journals with several presentations at professional conferences.