Abstract
Lithium-ion batteries utilizing 5V spinel material, LixMn1.5Ni0.5O4 have received considerable interest in recent years for their ability to deliver high energy and power densities. In this paper, we report an atomic scale analysis of the surface layer of a core-shell 5V spinel structure where a small amount of the manganese lattice sites have been substituted with cobalt in the shell to reach a stoichiometry of LixMn1.18Ni0.55Co0.27O4. Our analyses include electrochemical analysis, atom probe tomography (APT) analysis, kinetic analysis of the interfacial reactions, and high resolution scanning transmission electron microscopy (HR-TEM) analysis. The APT analysis is performed on the material before and after long-term cycling at room temperature to provide insights into the atomic scale phenomena within the surface layer of the electrode material. Our APT data reveals a 25-30 nano-meter (nm) region which forms after cycling. From our analyses, we believe that the outer few nanometers of this region stabilizes the 5V spinel within the chemical environment of the lithium-ion cell such that its structure is not compromised and thereby enables this material to cycle without significant capacity fading.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 297-306 |
| Number of pages | 10 |
| Journal | Nano Energy |
| Volume | 19 |
| DOIs | |
| State | Published - Jan 1 2016 |
Funding
This work was supported as part of the Center for Electrochemical Energy Science, an Energy Frontier Research Center funded by the U.S. Department of Energy , Office of Science, Basic Energy Sciences. Argonne National Laboratory is operated for the US Department of Energy by UChicago Argonne, LLC, under contract DE-AC02-06CH11357 . Use of the Center for Nanoscale Materials, including resources in the Electron Microscopy Center, was supported by the U. S. Department of Energy, Office of Science, Office of Basic Energy Sciences, as well as NUANCE-EPIC facility supported by the Initiative for Sustainability and Energy at Northwestern University. We are grateful to Andrew Jansen, Bryant Polzin, and Stephen Trask from the U.S. Department of Energy׳s (DOE) Cell Fabrication Facility (CFF), Argonne. The CFF is fully supported by the DOE Vehicle Technologies Program (VTP) within the core funding of the Applied Battery Research (ABR) for Transportation Program. This work was carried out in part in the Frederick Seitz Materials Research Laboratory Central Research Facilities, University of Illinois Urbana Champaign (UIUC). The authors also gratefully acknowledge the assistance and valuable discussions with Jim Mabon and Matthew D. Bresin from UIUC and Michael Thackeray and Larry Curtiss from Argonne National Laboratory.
Keywords
- 5V spinel
- Atom probe tomography
- Scanning transmission electron microscopy
ASJC Scopus subject areas
- Renewable Energy, Sustainability and the Environment
- General Materials Science
- Electrical and Electronic Engineering
