Nanostructured metal oxides are leading candidates for lithium ion battery anodes. Recent studies suggest that the presence of structural defects (e.g. vacancies and interstitials) in metal oxides may enhance the material’s electrochemical charge storage capacity. We are investigating a new approach to introduce defects into metal oxide electrode materials through the use of charged particle irradiation to produce a supersaturation of point defects in the target material. We specifically focus on TiO2 nanotube (TiO2-NT) electrodes. We investigate the effects of 100-400 keV proton irradiation on amorphous TiO2 nanotube electrodes at both room temperature and high temperature (250°C).
Upon room temperature irradiation the nanotubes demonstrate an irradiation-induced phase transformation from amorphous to a mixture of amorphous, anatase, and rutile domains. This phase transformation results in a 35% reduction in capacity compared to anatase TiO2. However, the high temperature proton irradiation induced a disordered rutile phase within the nanotubes, which exhibits a 20% improvement in capacity and improved rate capability. Structural characterization is conducted using Raman spectroscopy and transmission electron microscopy (TEM).
Following irradiation, the TiO2-NT electrodes have greater contribution from diffusion in lithium charge storage. Our results suggest that tailoring the defect generation through ion irradiation could present a new avenue for designing advanced metal oxide electrode materials.
- H. Xiong, K.A. Smith, A.I. Savva, C. Deng, Boise State University
- D.P. Butt, University of Utah
- S. Hwang and D. Su, Brookhaven National Laboratory
- Y. Wang, Los Alamos National Laboratory
- T. Xu and J. Gong, Northern Illinois University
- National Science Foundation grant number DMR-1408949
- Center for Integrated Nanotechnologies (CINT) – DOE Office of Science User Facility
- In-kind support from Brookhaven National Laboratory and Northern Illinois University
- K.A. Smith, A.I. Savva, C. Deng, J.P. Wharry, S. Hwang, D. Su, Y. Wang, J. Gong, T. Xu, D.P. Butt, and H. Xiong. Effects of proton irradiation on structural and electrochemical charge storage properties of TiO2 nanotube electrodes for lithium-ion batteries. Journal of Materials Chemistry A, in press. doi: 10.1039/c7ta01026e
- J.P. Wharry, K. Smith, H. Xiong, and D.P. Butt. Charged particle irradiation induced defect evolution in titania. The Minerals, Metals & Materials Society Annual Meeting, San Diego CA, March 2017.
- K. Smith, D.P. Butt, J.P. Wharry, and C. Xiong. Structural and electrochemical response to irradiation induced defects in TiO2 anodes for lithium-ion batteries. Electronic Materials and Applications 2017, American Ceramic Society, Orlando FL, January 2017.
- K.A. Smith, D.P. Butt, J.P. Wharry, and C. Xiong. Irradiation induced defects in titanium dioxide for energy storage applications. Materials Science & Technology (MS&T) 2016, Salt Lake City UT, October 2016.
- K. Smith, H. Xiong, J.P. Wharry, and D.P. Butt. Defect driven titania anode for secondary sodium and lithium batteries. Electronic Materials and Applications 2016, American Ceramic Society, Orlando FL, January 2016.