Organic electrolyte for high output liquid thermoelectric converter

A cheap and high-power liquid thermoelectric converter could be produced thanks to a new strategy pioneered and tested by Japan-based researchers.

They published their results on 22 November in the journal Industrial Chemistry & Materials.

The research team expanded the aqueous electrolyte used up until now to an organic electrolyte to increase the output of liquid thermoelectric converter (LTE), which converts temperature differences in the environment into electricity. Organic electrolytes generate higher thermoelectric power than aqueous electrolytes but have the disadvantage of high electrolyte resistance and low output, according to corresponding author Yutaka Moritomo, professor of physics at the University of Tsukuba.

"Among organic electrolytes, methanol and acetone solutions, which have relatively low electrolyte resistance, are promising candidates for high-output LTE," Moritomo said, promoting the development of LTE using organic electrolytes. "To increase output, it is necessary to reduce the electrolyte resistance. We adopted a strategy of breaking down the electrolyte resistance into its components and aiming to reduce each component."

First, the team decomposed the electrolyte resistance into resistance due to the solution and resistance due to the electrode reaction. They found that the resistance due to the electrode reaction of the methanol solution was even smaller than that of the corresponding aqueous solution. On the other hand, the resistance due to the solution can be reduced by shortening the distance between the electrodes. The team fabricated a prototype LTE with a small electrode distance and demonstrated that the output of the methanol LTE is equal to or greater than that of the aqueous LTE.

"The approach of decomposing the electrolyte resistance into its components is considered to be very effective for reducing electrolyte resistance and developing high-power LTEs," Moritomo said.

Next, the team plans to expand the search area for organic electrolytes from pure solvents to mixed solvents to promote the development of even higher-power LTEs.

Other co-authors are Touya Aiba, Graduate School of Pure and Applied Science in the University of Tsukuba; Haruka Yamada, School of Science and Engineering in the University of Tsukuba.

Industrial Chemistry & Materials is a peer-reviewed interdisciplinary academic journal published by Royal Society of Chemistry (RSC) with APCs currently waived. ICM publishes significant innovative research and major technological breakthroughs in all aspects of industrial chemistry and materials, especially the important innovation of the low-carbon chemical industry, energy, and functional materials. Check out the latest ICM news on the blog.