skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Olivine Composite Cathode Materials for Improved Lithium Ion Battery Performance

Abstract

Composite cathode materials in lithium ion batteries have become the subject of a great amount of research recently as cost and safety issues related to LiCoO2 and other layered structures have been discovered. Alternatives to these layered materials include materials with the spinel and olivine structures, but these present different problems, e.g. spinels have low capacities and cycle poorly at elevated temperatures, and olivines exhibit extremely low intrinsic conductivity. Previous work has shown that composite structures containing spinel and layered materials have shown improved electrochemical properties. These types of composite structures have been studied in order to evaluate their performance and safety characteristics necessary for use in lithium ion batteries in portable electronic devices, particularly hybrid-electric vehicles. In this study, we extended that work to layered-olivine and spinel-olivine composites. These materials were synthesized from precursor salts using three methods: direct reaction, ball-milling, and a coreshell synthesis method. X-ray diffraction spectra and electrochemical cycling data show that the core-shell method was the most successful in forming the desired products. The electrochemical performance of the cells containing the composite cathodes varied dramatically, but the low overpotential and reasonable capacities of the spinel-olivine composites make them a promising class for the next generationmore » of lithium ion battery cathodes.« less

Authors:
;
Publication Date:
Research Org.:
DOESC (USDOE Office of Science (SC) (United States))
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
1051809
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Undergraduate Research; Journal Volume: 6
Country of Publication:
United States
Language:
English

Citation Formats

Ward, R.M., and Vaughey, J.T. Olivine Composite Cathode Materials for Improved Lithium Ion Battery Performance. United States: N. p., 2006. Web.
Ward, R.M., & Vaughey, J.T. Olivine Composite Cathode Materials for Improved Lithium Ion Battery Performance. United States.
Ward, R.M., and Vaughey, J.T. Sun . "Olivine Composite Cathode Materials for Improved Lithium Ion Battery Performance". United States. doi:. https://www.osti.gov/servlets/purl/1051809.
@article{osti_1051809,
title = {Olivine Composite Cathode Materials for Improved Lithium Ion Battery Performance},
author = {Ward, R.M. and Vaughey, J.T.},
abstractNote = {Composite cathode materials in lithium ion batteries have become the subject of a great amount of research recently as cost and safety issues related to LiCoO2 and other layered structures have been discovered. Alternatives to these layered materials include materials with the spinel and olivine structures, but these present different problems, e.g. spinels have low capacities and cycle poorly at elevated temperatures, and olivines exhibit extremely low intrinsic conductivity. Previous work has shown that composite structures containing spinel and layered materials have shown improved electrochemical properties. These types of composite structures have been studied in order to evaluate their performance and safety characteristics necessary for use in lithium ion batteries in portable electronic devices, particularly hybrid-electric vehicles. In this study, we extended that work to layered-olivine and spinel-olivine composites. These materials were synthesized from precursor salts using three methods: direct reaction, ball-milling, and a coreshell synthesis method. X-ray diffraction spectra and electrochemical cycling data show that the core-shell method was the most successful in forming the desired products. The electrochemical performance of the cells containing the composite cathodes varied dramatically, but the low overpotential and reasonable capacities of the spinel-olivine composites make them a promising class for the next generation of lithium ion battery cathodes.},
doi = {},
journal = {Journal of Undergraduate Research},
number = ,
volume = 6,
place = {United States},
year = {Sun Jan 01 00:00:00 EST 2006},
month = {Sun Jan 01 00:00:00 EST 2006}
}
  • Graphical abstract: The preparation condition of Ni-rich cathode materials was investigated. When the retention time was short, a poor cathode performance was observed. For long retention time condition, cathode performance displayed a best result at pH 12. Highlights: Black-Right-Pointing-Pointer Ni-rich cathode materials (LiNi{sub 0.8}Co{sub 0.15}Al{sub 0.05}O{sub 2}) were prepared by co-precipitation method using separate addition of Al salt. Black-Right-Pointing-Pointer Particle size of Ni-rich cathode materials became larger with increase of retention time and solution pH. Black-Right-Pointing-Pointer Cathode performance was poor for low retention time. Black-Right-Pointing-Pointer Optimal pH for co-precipitation was 12. -- Abstract: Herein, Ni-rich cathode materials (LiNi{sub 0.8}Co{sub 0.15}Al{submore » 0.05}O{sub 2}) in lithium ion batteries are prepared by a separate addition of Ni/Co salt and Al sol solution using a continuously stirred tank reactor. Retention time and solution pH were controlled in order to obtain high performance cathode material. Particle size increase was observed with a higher retention time of the reactants. Also, primary and secondary particles became smaller according to an increase of solution pH, which was probably due to a decrease of growth rate. From the cathode application, a high discharge capacity (175 mAh g{sup -1}), a high initial efficiency (90%) and a good cycleability were observed in the cathode material prepared under pH 12 condition, which was attributed to its well-developed layered property and the optimal particle size. However, rate capability was inversely proportional to the particle size, which was clarified by a decrease of charge-transfer resistance measured in the electrochemical impedance spectroscopy.« less
  • Graphical abstract: MnO{sub 2} was blended into pristine Li[Li{sub 0.2}Mn{sub 0.44}Ni{sub 0.18}Co{sub 0.18}]O{sub 2} and Li[Li{sub 0.2}Mn{sub 0.44}Ni{sub 0.18}Co{sub 0.18}]O{sub 2}/MnO{sub 2} composite was obtained. We can observe that the adding MnO{sub 2} in the composite participates in the electrochemical reaction and provide more active sites for lithiation/delithiation. - Highlights: • Li[Li{sub 0.2}Mn{sub 0.44}Ni{sub 0.18}Co{sub 0.18}]O{sub 2}/MnO{sub 2} composite was synthesized by incorporation of MnO{sub 2} into spherical Li[Li{sub 0.2}Mn{sub 0.44}Ni{sub 0.18}Co{sub 0.18}]O{sub 2}. • Properties of spherical Li-rich layered oxide can be greatly improved by adding MnO{sub 2}. • The reason for the improvement of Li[Li{sub 0.2}Mn{sub 0.44}Ni{sub 0.18}Co{submore » 0.18}]O{sub 2}/MnO{sub 2} by adding MnO{sub 2} was explained. - Abstract: Spherical Li-rich layered Li[Li{sub 0.2}Mn{sub 0.44}Ni{sub 0.18}Co{sub 0.18}]O{sub 2} with high tap density and low specific surface area was synthesized. Furthermore, low cost and environmental benign MnO{sub 2} was blended into it and Li[Li{sub 0.2}Mn{sub 0.44}Ni{sub 0.18}Co{sub 0.18}]O{sub 2}/MnO{sub 2} composite was obtained. The properties of the materials were investigated by XRD, SEM and electrochemical method. The results showed that the existence of MnO{sub 2} in the composites can't change the structure of the pristine Li[Li{sub 0.2}Mn{sub 0.44}Ni{sub 0.18}Co{sub 0.18}]O{sub 2}. The electrochemical characteristics of Li[Li{sub 0.2}Mn{sub 0.44}Ni{sub 0.18}Co{sub 0.18}]O{sub 2}/MnO{sub 2} such as the initial coulombic efficiency, discharge capacity, rate characteristics and cyclability are much better than those of the pristine Li[Li{sub 0.2}Mn{sub 0.44}Ni{sub 0.18}Co{sub 0.18}]O{sub 2}. The contribution of MnO{sub 2} to the excellent characteristics of the cathode is as follows: the existence of MnO{sub 2} (i) provides more active site for lithiation/delitiation and (ii) suppresses side interaction between cathode particle surface and electrolyte.« less
  • Lithium transition metal fluorophosphates (Li{sub 2}MPO{sub 4}F, M: Co and Ni) have been investigated from atomistic simulation. In order to predict the characteristics of these materials as cathode materials for lithium ion batteries, structural property, defect chemistry, and Li{sup +} ion transportation property are characterized. The core–shell model with empirical force fields is employed to reproduce the unit-cell parameters of crystal structure, which are in good agreement with the experimental data. In addition, the formation energies of intrinsic defects (Frenkel and antisite) are determined by energetics calculation. From migration energy calculations, it is found that these flurophosphates have a 3Dmore » Li{sup +} ion diffusion network forecasting good Li{sup +} ion conducting performances. Accordingly, we expect that this study provides an atomic scale insight as cathode materials for lithium ion batteries. - Graphical abstract: Lithium transition metal fluorophosphates (Li{sub 2}CoPO{sub 4}F and Li{sub 2}NiPO{sub 4}F). Display Omitted - Highlights: • Lithium transition metal fluorophosphates (Li{sub 2}MPO{sub 4}F, M: Co and Ni) are investigated from classical atomistic simulation. • The unit-cell parameters from experimental studies are reproduced by the core–shell model. • Li{sup +} ion conducting Li{sub 2}MPO{sub 4}F has a 3D Li{sup +} ion diffusion network. • It is predicted that Li/Co or Li/Ni antisite defects are well-formed at a substantial concentration level.« less
  • POP–sulfur composite as cathode material for lithium–sulfur battery.