Ionic liquids for sustainable energy applications
Yansong ZHAO1
1Department of Safety, Chemistry and Biomedical Laboratory Sciences, Faculty of Engineering and Science, Western Norway University of Applied Sciences, Bergen, Norway
Ionic liquids for sustainable energy applications
Yansong Zhao*
Department of Safety, Chemistry and Biomedical Laboratory Sciences, Faculty of Engineering and Science, Western Norway University of Applied Sciences, 5063 Bergen, Norway
*Corresponding author and presenting author: Yansong Zhao (yansong.zhao@hvl.no).
Ionic liquids (ILs) are types of salts. ILs have many advantageous properties: (1) Low vapor pressure, high thermal and chemical stability; (2) Low melting point; (3) Phase behavior of ILs can be regulated by polarity modulation; (4) Favorable solubility in inorganic and organic chemicals; (5) Functional groups can be designed and synthesized to form functionized ILs. Due to advantageous properties of ILs, they can be utilized in wide fields. In my research group, we focus on utilization of ILs to develop sustainable energy technology.
First of all, a new generation self-powered and charged free battery is obtained in my research group. Ionic liquid based electrolyte is utilized for algae cultivation to form an algae battery, which can work continuously as a self-powered and charged free battery year by year. Algae are cultivated in my laboratory. ILs, light conditions, salt concentration, and discharge time on the performance of algae battery are investigated. Algae battery is a promising battery for sustainable energy devices applications.
In addition, nowadays, lithium-ion (Li) based batteries are important and are widely utilized as energy storage devices. However, Li-ion based batteries have several disadvantages, including high costs of the raw materials, safety issues, and limited Li resources in the earth. Therefore, researchers try to develop new generation batteries to replace Li-ion based batteries, including sodium (Na) based batteries, and magnesium (Mg) based batteries. However, costs of the Na and Mg based batteries are still high. In addition, flammable organic solvents are still utilized in Na and Mg based batteries. Therefore, Na and Mg based batteries still have similar safety issues. In our laboratory, ILs are utilized as electrolytes for a low cost and high safety battery: iron-ion battery (Fe-ion battery). Fe is the cheapest metal among all metallic materials. There are plenty of mineable Fe in the earth, ca. 230 billion tons. Element abundance of Fe rank No.1 in the universe and No.2 in the earth among metallic elements. This means that there are plenty of Fe in the nature for the Fe-ion battery fabrication. The cost of Fe-ion battery is much lower than the batteries mentioned above. Fe-ion battery is a kind of extremely safe battery. Ionic liquid based electrolyte in Fe-ion battery is not flammable, not oxygen or water sensitive, neither. Therefore, there is not safety issues in Fe-ion battery.
Moreover, ILs based electrolytes are designed and utilized for dye-sensitized solar cells (DSSC) fabrication. Traditional electrolytes of DSSC have temperature stability problems. ILs based electrolytes have higher stability than the traditional electrolytes. New generation of ILs based electrolyte are designed and utilized for DSSC fabrication in our laboratory.
References
(1) Y. Zhao, etal . ACS Omega, 2022, 7, 28, 24082-24090.
(2) Y. Zhao, etal. A self-powered and charged free ionic liquid electrolyte based algae battery, 2022 (under review).