Method—Deconvoluting Losses in Lithium-Ion Batteries via a Versatile Reference Electrode

This work enables high fidelity, virtual evaluation of prospective large format cell designs against program requirements early in the vehicle development process. It demonstrates conclusively the scalability of small, 3-electrode cell data to the large, commercial cell format. In doing so, it provides a protocol for the deconvolution of individual electrode resistances among the kinetics, ohmic, and transport domains at the 3-electrode level that can be directly translated to the same domains in a large format full cell. For the test cell seen in this work, this process details that the largest contribution to the overall losses in the battery cell are due to the anode kinetic and ohmic losses, followed by the losses due to the current collectors, internal leads, welds, and other electrical connections. This process can be generally applied to any electrochemical cell, and the materials and methods reported here can be utilized for any lithium-ion or sodium-ion battery. © 2024 The Author(s). Published on behalf of The Electrochemical Society by IOP Publishing Limited.