High Power Materials Development of Olivine System using Non-Stoichiometry or Surface Coating Method

Technology #12347

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Inventors
Professor Gerbrand Ceder
Department of Materials Science and Engineering, MIT
External Link (ceder.mit.edu)
Byoungwoo Kang
Department of Materials Science and Engineering, MIT
Managed By
Christopher Noble
MIT Technology Licensing Officer - Clean and Renewable Energy
Patent Protection

Oxide Coatings on Lithium Oxide Particles

US Patent 8,568,611
Publications
Battery materials for ultrafast charging and discharging
Nature, 458, 190-193 (12 March 2009)

Applications

Nano-sized coatings improve the performance of electrodes in lithium batteries. Lithium batteries have applications ranging from power tools to hybrid electric vehicles.

Problem Addressed

LiMPO4 materials are of interest for rechargeable Li batteries as they are safe, relatively inexpensive and very stable. However, LiMPO4 materials are relatively weak conductors; therefore, they are typically coated with carbon. This technology is a coating that is extremely stable, a good ionic and electronic conductor, and can be applied in-situ (during synthesis of the material) or ex-situ (after synthesis) of the electrode material.

Technology

Due to demand for lightweight, high energy density batteries, improvements in the energy storage of battery materials is needed. This coating is an amorphous or microcrystalline glass of Li-P-O-N-Fe. The coating can be applied in-situ or ex-situ and at a 44C rate the material has over 120 mAh/g capacity. At 60C the material retains 100 mAh/g capacity, the best performance observed for a LiFePO4 electrode. The material increases cyclability, rate capability, and capacity retention through increasing the electronic conductivity. 

Advantages

  • Can be applied in-situ or ex-situ
  • Increases cyclability, rate capability, and capacity retention