1. LiCoPO4 mechanical properties evaluated by nanoindentation.
- Author
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Wolfenstine, J., Allen, J. L., Jow, T. R., Thompson, T., Sakamoto, J., Jo, H., and Choe, H.
- Subjects
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LITHIUM compounds , *MECHANICAL properties of metals , *NANOINDENTATION , *LITHIUM-ion batteries , *ANNEALING of metals - Abstract
LiCoPO4 is a promising cathode material for use in high voltage Li-ion batteries. One of the problems with LiCoPO4 is limited cycle life. One possible cause for the limited cycle life of LiCoPO4 is mechanical degradation. As a consequence, the mechanical properties, elastic modulus, E, and fracture toughness, KIC, of hot-pressed dense (~98%) polycrystalline (15-20 µm) single phase LiCoPO4 were investigated. E for the hot-pressed LiCoPO4 specimen is ~137 GPa while the E value for the LiCoPO4 specimen after annealing at 600 °C is ~106 GPa. The fracture toughness of the hot-pressed LiCoPO4 sample is ~0.41 MPa m1/2, which increased to ~0.53 MPa m1/2 after annealing. These low KIC values reveal that LiCoPO4 is a brittle material. It is believed that the decrease in E and increase in KIC with annealing is associated with a reduction in residual stress. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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