• Kyoto University・AIST
  • Research and Development Initiative for Scientific Innovation
    of New Generation Batteries 2
  • RISING2 FY2016〜FY2020

Conversion-type Battery

Extremely high capacity can be achieved when Li+ insertion/deinsertion is carried out beyond the limits of the structural maintenance of the electrode materials. FeF3 is one such positive electrode material that enables the production of high-capacity, low-cost batteries in combination with metallic Li as the negative electrode. This battery system can be applied to xEVs and sustainable energy storage systems.

Features and Advantages

  • High theoretical energy from a multi-electron reaction in the conversion electrode
  • No oxygen evolution and improved safety
  • Low-cost materials

R&D Themes

  • Development of long-life and high-energy-efficiency positive electrode materials
  • Development of long-life negative electrode structure and surrounding components
  • Optimization of the overall cell design for balanced performance
conversion-type cell

R&D Strategies

  • Positive electrode: understanding the source of large hysteresis during operation and improving the technology, as well as side-reaction suppression technology
  • Negative electrode: understanding the area to be improved when considering the total cell reaction
  • Electrolyte and inactive battery components suitable for electrode materials

Research Results

Developing a prototype cell of high performance through improving the FeF3 electrode process and its electrolyte

prototype and its charge–discharge curves

The prototype cell (6 Ah-class) and its charge–discharge curves, which demonstrated 319 Wh/kg energy density.

Improvement of energy efficiency

Improvement of energy efficiency using a composite with vanadate glass.

degradation mechanism

Understanding the degradation mechanism by applying advanced analysis technology.