Abstract
Soft chemistry techniques, such as ion exchange, hold great potential for the development of battery electrode materials that cannot be stabilized via conventional equilibrium synthesis methods. Nevertheless, the intricate mechanisms governing ion exchange remain elusive. Herein, we investigate the evolution of the long-range and local structure, as well as the ion (de)intercalation mechanism during electrochemical Li-to-Na ion exchange initiated from an O3-type lithium-layered oxide cathode. The in situ-formed mixed-cation electrolyte leads to competitive intercalation of Li and Na ions. While Li ion intercalation predominates at the beginning of initial discharge, Na ion cointercalation into a different layer results in ion redistribution and phase separation, with the emergence of a P3-Na phase alongside an O3-Li phase. Further, this study spatially resolves the heterogeneous nature of electrochemical ion exchange reactions within individual particles and provides insights into the correlations between local Ni redox processes and phase separation. Overall, electrochemical ion exchange leads to a mixed-phase cathode and alters its reaction kinetics. Those findings have important implications for the development of new metastable materials for renewable energy devices and ion separation applications.
| Original language | English |
|---|---|
| Pages (from-to) | 26916-26925 |
| Number of pages | 10 |
| Journal | Journal of the American Chemical Society |
| Volume | 146 |
| Issue number | 39 |
| DOIs | |
| State | Published - Oct 2 2024 |
Funding
The work was supported by the National Science Foundation, DMR-1832613 for Li ion, and CBET 1912885 for Na ion. L.M. was also supported by the School for Engineering of Matter, Transport, and Energy Startup at Arizona State University. Use of the Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, is supported by the US Department of Energy, Office of Science, Office of Basic Energy Sciences under Contract No.DE-AC02-76SF00515. The neutron measurements used resources at the Spallation Neutron Source, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory. This research used Beamline 7-BM of the National Synchrotron Light Source II, a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Brookhaven National Laboratory under Contract No. DE-SC0012704. The NMR measurements reported here made use of the shared facilities of the Materials Research Science and Engineering Center (MRSEC) at UC Santa Barbara (NSF DMR 2308708). E.E.F. was supported by the NSF Graduate Research Fellowship Program under grant no. DGE 1650114, and E.E.F and R.J.C acknowledge the support from an NSF CAREER award under award no. DMR 2141754. J.-M.H. acknowledges the donors of the American Chemical Society Petroleum Research Fund for partial support of this research, under the award PRF # 61594-DNI9, as well as the support from NSF grant CBET-2006028. The phase-field simulations were performed using Bridges at the Pittsburgh Supercomputing Center through allocation TG-DMR180076 from the Advanced Cyberinfrastructure Coordination Ecosystem: Services & Support (ACCESS) program, which is supported by NSF grants #2138259, #2138286, #2138307, #2137603, and #2138296. NMC was produced at the U.S. Department of Energy\u2019s (DOE) CAMP (Cell Analysis, Modeling and Prototyping) Facility, Argonne National Laboratory. The CAMP Facility is fully supported by the DOE Vehicle Technologies Program (VTP) within the core funding of the Applied Battery Research (ABR) for Transportation Program. F.L. and L.M. thank Dr. Kai He for assistance with STEM-mapping.