Pore Alignment Impacts on Lithium Ion Transport and Rate Capability of Thick Sintered Electrodes

Published

June 25, 2021

Author(s)

Daniel Hussey, Jacob LaManna, David Jacobson, Gary Koenig

Abstract

Increasing electrode thickness is one route to improve the energy density of lithium-ion battery cells. However, restricted Li+ transport in the electrolyte phase through the porous microstructure of thick electrodes limits the ability to achieve high current densities and rates of charge/discharge with these high energy cells. In this work, processing routes to mitigate these transport restrictions were pursued. The electrodes used were comprised of only active material sintered together into a porous pellet. For one of the electrodes, comparisons were done between using ice-templating to provide directional porosity and using sacrificial particles during processing to match the pore volume fraction but without any preferential pore alignment. The electrodes with directional porosity retained much greater discharge capacity at higher rates of cycling, which was attributed to the lower tortuosity and improved transport properties provided by the ice-templated processing. The electrodes were further characterized using an electrochemical model of the cells evaluated and neutron imaging of a cell containing the ice-templated pellet, to provide further support that the observed improvements in capacity retention at higher discharge rate was due to improving the Li+ transport properties in the electrode microstructure. These results indicate that significant improvements can be made to electrochemical cell properties and cycling performance via templating the pore microstructure for situations where the rate limiting step includes ion transport limitations in the cell, as is the case for very thick electrodes.

Citation

journal of the electrochemical society

Pub Type

Journals

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Keywords

lithium ion battery, neutron imaging, sintered electrode, electrochemical modeling, alternative energy

Citation

Hussey, D. , LaManna, J. , Jacobson, D. and Koenig, G. (2021), Pore Alignment Impacts on Lithium Ion Transport and Rate Capability of Thick Sintered Electrodes, journal of the electrochemical society, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=931890 (Accessed December 13, 2024)