Higher energy densities in rechargeable batteries can be achieved using thicker cathode films, though it is a challenging endeavor since the electrochemical performance of thick electrodes is substantially worse than that of the conventional thin electrodes due to a variety of transport limitations, which are thus far poorly understood. Operando synchrotron studies have been, for the first time, applied to thick film samples to determine the depth-dependent state of charge (SOC) distribution inside 170 micron thick Li(Ni0.8Mn0.1Co0.1)O2 cathode films using an unconventional radial diffraction experiment geometry, allowing the SOC to be probed with both high spatial resolution (20 microns) and high temporal resolution (hundreds of time steps) in a single experiment. The resulting data allow the evolution of vertical inhomogeneity within these thick cathode films to be determined during cycling and they reveal a number of unexpected phenomena, such as the continuation of charging at some heights within the cathode during the discharge cycle of the cell. The new availability of comprehensive depth-dependent SOC data will drive the parameterization and advancement of whole-cell models, leading to an improved understanding of large-scale transport phenomena and enhanced capabilities for the rational design of thick electrodes with improved performance.
|Number of pages||7|
|Journal||Chemistry of Materials|
|Publication status||Published - 2020 Aug 11|
Bibliographical noteFunding Information:
This work was supported by the Assistant Secretary for Energy Efficiency and Renewable Energy, Office of Vehicle Technologies of the U.S. Department of Energy (DOE) through the Advanced Battery Materials Research (BMR) program and the Battery500 Consortium under Contract No. DE-SC0012704. Research was in part carried out at Brookhaven National Laboratory, which is supported by the U.S. Department of Energy, Office of Basic Energy Sciences, under Contract No. DE-SC0012704. The use of the Advanced Photon Source at Argonne National Laboratory was supported by the U. S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. We gratefully acknowledge the support of the staff at beamlines 11-ID-B (O. Borkiewicz) and 11-BM (S. Lapidus) as well as the use of the dedicated eChem lab facility (K. Wiaderek). We gratefully acknowledge internal discussions with many of our Battery500 Consortium collaborators on experimental and theoretical aspects of depth-dependent measurements, especially Eric Dufek, Y. Shirley Meng, and Michael Toney.
© 2020 American Chemical Society.
All Science Journal Classification (ASJC) codes
- Chemical Engineering(all)
- Materials Chemistry