Newly developed compound may enable sustainable, cost-effective, large-scale energy storage

To nutrient a cost-effective redox travel battery, researchers based astatine the South China University of Technology person synthesized a molecular compound that serves arsenic a low-cost electrolyte, enabling a unchangeable travel artillery that retains 99.98% capableness per cycle. They published their attack connected August 14 successful the Energy Material Advances.

Comprising 2 tanks of opposing liquid electrolytes, the artillery pumps the affirmative and antagonistic liquids on a membrane separator sandwiched betwixt electrodes, facilitating ion exchanges to nutrient energy. Significant enactment has been dedicated to processing the antagonistic electrolyte liquid, portion the affirmative electrolyte liquid has received little attention, according to corresponding writer Zhenxing Liang, prof successful the Key Laboratory of Fuel Cell Technology of Guangdong Province, School of Chemistry and Chemical Engineering, South China University of Technology.

"Aqueous redox travel batteries tin recognize the unchangeable electrical output for utilizing unsteady star and upwind energy, and they person been recognized arsenic a promising large-scale vigor retention technology," Liang said. "Electroactive integrated merit of constituent abundance, debased outgo and flexible molecular power implicit the electrochemical features for some affirmative and antagonistic electrolytes are regarded arsenic cardinal to processing next-generation redox travel batteries."

Liang and his squad focused connected TEMPO, a chemic compound with easy reversed oxidation states and precocious imaginable for energy, a desired prime successful affirmative electrolytes.

"However, TEMPO cannot beryllium straight applied to aqueous redox travel batteries owed to the precocious hydrophobicity of the molecular skeleton," Liang said, explaining that TEMPO, near unmodified, volition not dissolve successful the liquid needed to facilitate the vigor speech successful the travel batteries. "We developed a strategy to functionalize TEMPO with viologen, an integrated compound that has highly reversible redox reactions, to amended TEMPO's hydrophilicity."

According to Liang, viologen is highly soluble successful water, which increases TEMPO's quality to dissolve successful water. Viologen besides chemically withdraws electrons from atomic partners, which elevates its imaginable to alteration its oxidative state. Viologen is besides a salt, which endows TEMPO with what Liang calls "a decent conductivity" successful an aqueous solution.

When the synthesized viologen-modified TEMPO was tested successful a travel battery, the researchers recovered that the artillery retained capableness of 99.98% per cycle, meaning the artillery could clasp astir each its stored vigor erstwhile not successful progressive use.

"This enactment overcomes the disadvantages of TEMPO by viologen-functionalization and realizes its exertion successful aqueous redox travel battery," Liang said. "The molecular plan conception provides a strategy for caller integrated electroactive materials and lays a instauration for the exertion of aqueous integrated flow battery."

Other contributors see Shuzhi Hu, Liwen Wang, Xianzhi Yuan, Zhipeng Xiang, Mingbao Huange, Peng Luo, Yufeng Liu and Zhiyong Fu, each with the Key Laboratory of Fuel Cell Technology of Guangdong Province, School of Chemistry and Chemical Engineering, South China University of Technology. Hu is besides affiliated with the School of Materials Science and Engineering, Sun Yat-sen University.

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More information: Shuzhi Hu et al, Viologen-Decorated TEMPO for Neutral Aqueous Organic Redox Flow Batteries, Energy Material Advances (2021). DOI: 10.34133/2021/9795237

Provided by Beijing Institute of Technology Press Co., Ltd