Operating principles, development challenges, and future prospects of next-generation secondary batteries.

Research trends, possibilities, and points to be addressed regarding sodium cluster secondary batteries and organic secondary batteries: high energy density, safety, and application prospects.

**Part 1:** High-performance batteries are being sought as next-generation batteries, and the market for secondary batteries is emerging in two types: mobile and stationary. The latter is a market where cost is prioritized, but considering future resource risks, the concept of sodium secondary batteries is emerging. **Part 2:** In this lecture, I would like to explain a new type of secondary battery that uses metal cluster complexes (molecular clusters) and their nano-composites as positive electrode active materials, discussing their principles, performance, and reaction mechanisms, as well as the potential for these to exceed the performance of currently mainstream lithium-ion batteries. **Part 3:** Various approaches are being taken to develop new secondary batteries that can handle energy more efficiently. "Multi-electron organic secondary batteries" are a new type of secondary battery that utilizes multi-electron reactions of organic compounds for charging and discharging, and are expected to feature high energy density, safety, low environmental impact, and low cost. The lecture will introduce the operating principles, development status, and future prospects of such multi-electron organic secondary batteries, and discuss their potential as next-generation secondary batteries.

Technical Seminar