SANKEN, Osaka University


Division of Advanced Materials and Beam Science

Department of Energy and Environmental Materials


  • Prof.
  • Assoc. Prof.
  • Assis. Prof.
    Y. KONDO
Ryansu Sai
  • Specially Appointed Assis. Prof.
    Ryansu Sai

Content of research

Our group is engaged in the development of new materials and reactions toward high-energy-density and safe rechargeable batteries. Through our unique strategy of controlling the coordination states of ions and solvent molecules in electrolyte materials, we are developing new functions and properties that are not found in conventional electrolytes. We are also pursuing the possibility of new rechargeable batteries by utilizing the developed electrolyte materials. Our research achievements include the development of high-voltage lithium-ion batteries by widening the potential window of electrolytes (Nature Communications 2016, Nature Energy 2019), rapid charging of lithium-ion batteries using unique electrode/electrolyte interphases (Journal of the American Chemical Society 2014), development of safe lithium-ion batteries using flame-retardant and fire-extinguishing organic electrolytes (Nature Energy 2018), discovery of alkaline metal salt hydrate melts and development of high-voltage aqueous batteries using hydrate melt electrolytes (Nature Energy 2016, Angewandte Chemie 2019), and design and synthesis of a new electrolyte solvent that is both flame-retardant and voltage-resistant (Nature Energy 2020). We will continue to explore unknown functions and properties of electrolyte materials and develop new rechargeable batteries that contribute to solving energy and environmental issues.

Current Research Programs

  • 1. Development of new electrolyte materials through our original design strategies
    2. Establishment of new theories and science on liquid material chemistry
    3. Analysis of electrode/electrolyte interfacial reactions and active control of the interfacial states/structures
    4. Development of new reactions for high-density energy storage
    5. Development of new rechargeable battery devices

Figure / Graph

  • Electrode/electrolyte interface in rechargeable batteries
リチウム塩水和融体の発見と新型高電圧水系電池(Nature Energy, 1, 16129 (2016))
  • Discovery of lithium salt hydrate melts and development of high-voltage aqueous batteries (Nature Energy, 1, 16129 (2016))
新規電解液溶媒の設計(Nature Energy, 5, 291 (2020))
  • Design of new electrolyte solvent (Nature Energy, 5, 291 (2020))