Development of Nanostructured High-voltage Cathode Materials for Use in Advanced Lithium-Ion Cells
Funded by U.S. Department of Energy
Project Summary
The goal of this SBIR Phase I project was to develop and demonstrate a new class of nanoparticle-sized cathode composites based on olivine phosphate LiCoPO4 that has have an output 4.8 volts relative to lithium metal. This class of materials is expected to offer better performance over currently used cathode materials, including higher voltages, larger capacities, and better stability, and therefore is attractive for use in a Li-ion cell for hybrid electric vehicles (HEVs) or in other applications. The research conducted in Phase I, which included material design, synthesis, prototyping, and characterization, well demonstrated the technical feasibility of the proposed materials. The key technical issues related to material processing for the production of LiCoPO4/C nanocomposites were well addressed and preliminary characterization and prototyping in order to evaluate electrochemical performance has been conducted. In addition, the synthesis and characterization of doped LiCoPO4 and LiFePO4 have also been carried out. The methodology, including one-step synthesis of LiCoPO4/C and doped LiCoPO4, can be utilized to synthesize other LiMPO4-type (M = Fe, or Mn, or Co, or Ni) cathode materials, for instance, LiMnPO4 (voltage of 4.2 V) and to further improve the performance of LiFePO4. In the end of this Phase I project, our preliminary research has also pointed to a new material processing approach of doped LiMPO4/C nanocomposite that can be cost-effectively processed with a single-step processing with the aid of high energy ball milling. Consequently, the investigative study carried out in Phase I has established a solid technical basis for Phase II of the project, which will focus on process optimization, scaling up, system demonstration.