Abstract
Advanced battery characterization using in situ/operando neutron imaging is critical for uncovering degradation modes such as lithium (Li) plating in Li-ion batteries (LIBs). However, conventional LIBs hinder operando neutron radiography (NR) and in situ neutron micro-computed tomography (N-μCT) for visualizing Li plating near the graphite-separator interface due to strong attenuation from hydrogen-rich components like PP-PE-PP separators, electrolyte, and Fe-based spacers. In this work, we designed and tested a neutron-friendly battery (NFB) optimized for in situ Li detection during extreme fast charging (XFC). Guided by neutron attenuation cross-sections and material transmission, the NFB enables clear visualization at the graphite-separator interface, which is typically opaque in standard LIBs. Electrochemical tests show the NFB exhibits voltage/current responses like standard cells for up to 50 XFC cycles. However, its lower reversibility and capacity are likely due to Cu-coated Al spacer degradation from delamination or corrosion. We propose titanium spacers as a more stable alternative, albeit requiring custom machining. Using this optimized cell, we achieved simultaneous neutron tomography of multiple cells, capturing in situ 3D images of dead Li accumulation, particularly near graphite edges. These heterogeneous deposits and disconnected Li clusters suggest localized current density hotspots during XFC.
| Original language | English |
|---|---|
| Article number | 090531 |
| Journal | Journal of the Electrochemical Society |
| Volume | 172 |
| Issue number | 9 |
| DOIs | |
| State | Published - Sep 1 2025 |
Funding
Funding was provided from the Vehicle Technologies Office of the U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy under the guidance of the Advanced Battery Cell Research Program (eXtreme fast charge Cell Evaluation of Lithium-ion batteries, XCEL). Work was performed in part in the nano@Stanford laboratories, which are supported by the National Science Foundation as part of the National Nanotechnology Coordinated Infrastructure under award ECCS-1542152. The Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, is supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Contract No. DE-AC02-76SF00515. The Argonne National Laboratory is operated for the U.S. Department of Energy by UChicago Argonne, LLC, under the contract number DE-AC02-06CH11357. Idaho National Laboratory is operated by Battelle Energy Alliance, LLC under Contract No. DE-AC07-05ID14517 for the U.S. Department of Energy. A portion of this research used resources at the High Flux Isotope Reactor, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory. The beam time was allocated to MARS (CG-1D) on proposal number IPTS-27158. This work was partially supported by the U.S. Department of Commerce, the NIST Radiation Physics Division, the Director’s office of NIST, and the NIST Center for Neutron Research. We are grateful to Dr. Kipil Lim for discussions on electrochemical characterization of LIB at fast charging. We would also like to acknowledge Dr. Hassina Bilheux for fruitful discussions on neutron imaging for plated Li detection. PPP acknowledges funding by EPSRC for the International Center to Center Collaboration with the ESRF grant reference EP/W003333/1 and the Henry Royce Institute established through EPSRC grants EP/R00661X/1, EP/P025498/1 and EP/P025021/1. M.Y. gratefully acknowledges the Schlumberger Foundation for its support through the Faculty for the Future Fellowship (2018-2023), the Stanford Office of the Vice Provost for Graduate Education for financial assistance through the DARE (Diversifying Academia, Recruiting Excellence) Doctoral Fellowship Program (2020-2022), and the Electrochemical Society for the Edward G. Weston Summer Fellowship 2022. The authors declare no competing financial interest. Notice of Copyright. This manuscript has been authored by UT-Battelle, LLC under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan (http://energy.gov/downloads/doe-public-access-plan). Funding was provided from the Vehicle Technologies Office of the U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy under the guidance of the Advanced Battery Cell Research Program (eXtreme fast charge Cell Evaluation of Lithium-ion batteries, XCEL). Work was performed in part in the nano@Stanford laboratories, which are supported by the National Science Foundation as part of the National Nanotechnology Coordinated Infrastructure under award ECCS-1542152. The Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, is supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Contract No. DE-AC02-76SF00515. The Argonne National Laboratory is operated for the U.S. Department of Energy by UChicago Argonne, LLC, under the contract number DE-AC02-06CH11357. Idaho National Laboratory is operated by Battelle Energy Alliance, LLC under Contract No. DE-AC07-05ID14517 for the U.S. Department of Energy. A portion of this research used resources at the High Flux Isotope Reactor, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory. The beam time was allocated to MARS (CG-1D) on proposal number IPTS-27158. This work was partially supported by the U.S. Department of Commerce, the NIST Radiation Physics Division, the Director’s office of NIST, and the NIST Center for Neutron Research. We are grateful to Dr. Kipil Lim for discussions on electrochemical characterization of LIB at fast charging. We would also like to acknowledge Dr. Hassina Bilheux for fruitful discussions on neutron imaging for plated Li detection. PPP acknowledges funding by EPSRC for the International Center to Center Collaboration with the ESRF grant reference EP/W003333/1 and the Henry Royce Institute established through EPSRC grants EP/R00661X/1, EP/P025498/1 and EP/P025021/1. M.Y. gratefully acknowledges the Schlumberger Foundation for its support through the Faculty for the Future Fellowship (2018–2023), the Stanford Office of the Vice Provost for Graduate Education for financial assistance through the DARE (Diversifying Academia, Recruiting Excellence) Doctoral Fellowship Program (2020–2022), and the Electrochemical Society for the Edward G. Weston Summer Fellowship 2022. The authors declare no competing financial interest. Notice of Copyright. This manuscript has been authored by UT-Battelle, LLC under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan ( http://energy.gov/downloads/doe-public-access-plan ).
Keywords
- Li metal deposition
- extreme fast charging
- graphite-separator interface
- high-resolution neutron imaging
- in situ/operando cell design