Olivine Phosphate Cathode Materials, Reactivity and Reaction Mechanisms
Crystalline size has tremendous effect to the thermodynamics and kinetics in intercalation compounds. This includes diffusion/transport length, effective surface area for exchange current, surface energy, and interphase energy. The focus now is on Li x FePO4, where the phase changes by simple two-phase separation but with controllable miscible character by raising temperature and/or reducing crystalline size, thereby provides simple model system to rationalize thermodynamics and electrochemistry in electrode reaction. Systematic experimental results on this issue are reviewed and summarized. Negative aspects of nanoparticle including surface poisoning by air contact and its diagnosis will be also demonstrated. As an atomic-scale phenomenon, experimental verification of one-dimensional lithium diffusion in Li x FePO4 will be also demonstrated.
KeywordsTiO2 Entropy Toxicity Anisotropy Enthalpy
Oxidizing agent in Battery.
Spontaneous movement of some species (ions in the present case).
A promising low-cost and safe cathode materials for LIB.
- Lithium-ion battery (LIB)
A rechargeable battery with highest energy density.
- Miscibility gap
A compositional region where two species cannot mix.
A name of mineral Mg2SiO4 with identical structure of LiFePO4.
- Phase diagram
Stable phase map as a function of composition, temperature.
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