Highly stabilized and efficient thermoelectric copper selenide
Haihua Hu1, Yiwei Ju1,2,3, Jincheng Yu4
1State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, China.
Nature Materials
|March 7, 2024
Summary
Researchers enhanced thermoelectric superionic conductors by confining ion migration, boosting performance and stability. This ion confinement strategy improves the figure of merit (ZT) and device longevity for efficient energy conversion.
Area of Science:
- Materials Science
- Solid-State Chemistry
- Energy Conversion
Background:
- Thermoelectric superionic conductors offer low thermal conductivity due to ion migration but suffer from poor stability.
- Uncontrolled ion movement in these materials leads to degradation and reduced device lifespan.
- Developing stable and efficient thermoelectric materials requires managing ion dynamics.
Purpose of the Study:
- To enhance the figure of merit (ZT) and operational stability of Cu1.99Se-based superionic conductors.
- To investigate the effects of ion confinement on thermoelectric properties and material stability.
- To develop a strategy for creating robust functional materials with controlled ionic migration.
Main Methods:
- Utilized density functional theory (DFT) and nudged elastic band (NEB) simulations to guide material design.
- Employed a cation-anion co-doping strategy to increase ion migration activation energy.
- Fabricated and tested thermoelectric device modules based on the modified Cu1.99Se material.
Main Results:
- Achieved a figure of merit (ZT) of approximately 3.0 at 1050 K through ion confinement.
- Successfully reduced carrier concentration while maintaining low thermal conductivity.
- Demonstrated high device module conversion efficiency of ~13.4% for a 518 K temperature difference.
- Maintained performance over 120 cycles without significant degradation.
Conclusions:
- Ion confinement via co-doping is an effective strategy for simultaneously enhancing ZT and stability in superionic conductors.
- The developed Cu1.99Se-based material shows promise for high-performance, long-lasting thermoelectric applications.
- This approach offers a pathway for designing robust functional materials with tunable ionic migration characteristics.
