Abstract
The practical implementation of Co-free, LiNiO2-derived cathodes has been prohibited by their poor cycle life and thermal stability, resulting from the structural instability, phase transformations, reactive surfaces, and chemomechanical breakdown. With the hierarchical distribution of Mg/Ti dual dopants in LiNiO2, we report a Co-free layered oxide that exhibits enhanced bulk and surface stability. Ti shows a gradient distribution and is enriched at the surface, whereas Mg distributes homogeneously throughout the primary particles. The resulting Mg/Ti codoped LiNiO2 delivers a material-level specific energy of ∼780 W h/kg at C/10 with 96% retention after 50 cycles. The specific energy reaches ∼680 W h/kg at 1C with 77% retention after 300 cycles. Furthermore, the Mg/Ti dual dopants improve the rate capability, thermal stability, and self-discharge resistance of LiNiO2. Our synchrotron X-ray, electron, and electrochemical diagnostics reveal that the Mg/Ti dual dopants mitigate phase transformations, reduce nickel dissolution, and stabilize the cathode-electrolyte interface, thus leading to the favorable battery performance in lithium metal and graphite cells. The present study suggests that engineering the dopant distribution in cathodes may provide an effective path toward lower cost, safer, and higher energy density Co-free lithium batteries.
| Original language | English |
|---|---|
| Pages (from-to) | 9769-9776 |
| Number of pages | 8 |
| Journal | Chemistry of Materials |
| Volume | 31 |
| Issue number | 23 |
| DOIs | |
| State | Published - Dec 10 2019 |
| Externally published | Yes |
Funding
This material is based upon the work supported by the U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy (EERE) under the award number: DE-EE0008444. W.H.K. appreciates the beamtime in ECHIDNA granted from Australian Centre for Neutron Scattering (CSNS) in ANSTO. The use of 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. Professor Greg Liu and Dr. Tianyu Liu are acknowledged for collecting the N physisorption data. 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. W.H.K. thank the support from the National Natural Science Foundation of China (11805034 and 21704105). 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. 2 This material is based upon the work supported by the U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy (EERE) under the award number: DE-EE0008444. W.H.K. appreciates the beamtime in ECHIDNA granted from Australian Centre for Neutron Scattering (CSNS) in ANSTO. The use of 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. Professor Greg Liu and Dr. Tianyu Liu are acknowledged for collecting the N2 physisorption data. 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. W.H.K. thank the support from the National Natural Science Foundation of China (11805034 and 21704105). 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.