Abstract
Achieving the targeted control of layered oxide properties calls for more fundamental studies to mechanistically probe their evolution during their synthesis. Herein, dopant distribution, phase propagation, and local chemical changes as well as their interplay in multielement-doped LiNiO2 materials are investigated using spectroscopic, imaging, and scattering techniques. It is shown that dopants undergo dynamic redistribution in the Ni(OH)2 host lattice at the early stage of calcination (below 300 °C). Such redistribution behavior exhibits strong dopant-dependent characteristics, allowing for targeted surface and bulk doping control. The Ni oxidation process exhibits depth-dependent characteristics and the most rapid Ni oxidation takes place between 300 and 700 °C. Using Ni oxidation state as the proxy for the phase transformation, the buildup of heterogenous phase propagation in the early stage of calcination is shown, especially along the radial direction of secondary particles. The radial heterogenous phase distribution gradually decreases upon completing the calcination. However, a high degree of mosaic-like heterogeneity may still be present in the final product, departing from the perfect layered oxide. The present study offers fundamental insights into manipulating multiscale materials properties during calcination for obtaining stable, high-energy layered oxide cathodes.
| Original language | English |
|---|---|
| Article number | 2002719 |
| Journal | Advanced Energy Materials |
| Volume | 11 |
| Issue number | 1 |
| DOIs | |
| State | Published - Jan 7 2021 |
Funding
The work was supported by the U.S. Department of Energy's Office of Energy Efficiency and Renewable Energy (EERE) under the award number: DE‐EE0008444. The use of the Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Contract no. DE‐AC02‐76SF00515. This research used resources of the Advanced Photon Source, a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract no. DE‐AC02‐06CH11357. The research used 18‐ID 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 use of the Spallation Neutron Source at Oak Ridge National Laboratory was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Contract no. DE‐AC05‐00OR22725. This work was performed in part at the Surface Analysis Laboratory in Department of Chemistry at Virginia Tech, which was supported by the National Science Foundation under grant no. CHE‐1531834. This research was partially supported by Virginia Tech's Institute for Critical Technology and Applied Science through instruments provided by the Nanoscale Characterization and Fabrication Laboratory (NCFL). The authors acknowledge the assistance of Dr. Thomas W. Staley on the TGA experiment. The authors also acknowledge the assistance of Dr. Yijin Liu, Dr. Xu Feng, and Dr. Chunguang Kuai on the data analysis. Z.Y. and F.L. thank Dr. Yijin Liu's research group for the initial proof‐of‐concept TXM studies. This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. The work was supported by the U.S. Department of Energy's Office of Energy Efficiency and Renewable Energy (EERE) under the award number: DE-EE0008444.?The use of the Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Contract no. DE-AC02-76SF00515. This research used resources of the Advanced Photon Source, a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract no. DE-AC02-06CH11357. The research used 18-ID 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 use of the Spallation Neutron Source at Oak Ridge National Laboratory was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Contract no. DE-AC05-00OR22725. This work was performed in part at the Surface Analysis Laboratory in Department of Chemistry at Virginia Tech, which was supported by the National Science Foundation under grant no. CHE-1531834. This research was partially supported by Virginia Tech's Institute for Critical Technology and Applied Science through instruments provided by the Nanoscale Characterization and Fabrication Laboratory (NCFL). The authors acknowledge the assistance of Dr. Thomas W. Staley on the TGA experiment. The authors also acknowledge the assistance of Dr. Yijin Liu, Dr. Xu Feng, and Dr. Chunguang Kuai on the data analysis. Z.Y. and F.L. thank Dr. Yijin Liu's research group for the initial proof-of-concept TXM studies. This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.
Keywords
- Co free
- Li-ion batteries
- calcination
- dopant distribution
- layered oxides
