Today, batteries have become an essential part of our daily life, and everything from mobile phones and smart watches to electric vehicles depends on them. However, most batteries contain dangerous, toxic, and corrosive materials that can pollute the human environment if disposed of in landfills or dumped elsewhere.
Most batteries contain materials such as lead, cadmium, and mercury, which can poison humans and animals, cause soil and water pollution, and remain in the environment for a long time.
A team of researchers from Flinders University in South Australia and Zhejiang University of Science and Technology in China have done extensive research to produce the first non-toxic battery. The research that resulted in the first stage of the development of a new, non-toxic aluminum-ion battery was completed. Rechargeable aluminum ion batteries (AIBs) have recently attracted much attention due to their high theoretical volumetric capacity and good safety, and these batteries have potentially become a sustainable and low-cost energy storage system due to these features.
The battery system consists of cathode, anode and electrolyte, the first component must produce metal and positive ions, and the third component must be in such a way that the movement of ions can be done easily. For this reason, one of the main challenges for AIBs scientists is the slow mobility of Al+3 ion complexes, which leads to AIBs with low cathodic efficiency.
The solution for this problem is to use some kind of organic conjugated polymers. These polymers are considered as promising candidates for cathode materials for AIBs to address the ion transport problem, but their battery voltage output performance is still poor, so scientists are looking for better solutions.
Of course, stable radicals are a class of electroactive organic molecules that are widely used in various organic battery systems. These materials offer several advantages such as higher stability in production, tunable electrochemical properties, and many favorable structural properties.
Previously, researchers had produced radical materials for lithium-ion organic hybrid batteries (LIBs), sodium-ion batteries, and all-organic batteries. But these materials have not been used in emerging rechargeable aluminum ion batteries due to the problem of chemical reactions in electrolytes.
The new aluminum batteries are made using special materials called stable organic radicals, which contain the vital component 2,2,6,6-tetramethylpiperidyl-1-oxy (TEMPO). Instead of using harmful chemicals, these batteries use an aqueous electrolyte with a high concentration of acid.
The use of these water-based electrolytes has helped researchers develop the first design of water-polymer AIBs that are flame retardant and weather stable. They also provide a stable output voltage of 1.25 V and a capacity of 110 mAh-g at 800 cycles.
Researchers hope to use biodegradable materials to develop batteries in the future so that the manufactured product is safe and sustainable. In conclusion, this research work shows the way to use electroactive organic materials for cost-effective and safe AIBs that currently rely on conjugated organic molecules.
The research results are published in the following article:
Shangxu Jiang, Yihui Xie, Yuan Xie, Li-Juan Yu, Xiaoqing Yan, Fu-Gang Zhao, Chanaka J. Mudugamuwa, Michelle L. Coote, Zhongfan Jia, and Kai Zhang. Lewis Acid-Induced Reversible Disproportionation of TEMPO Enables Aqueous Aluminum Radical Batteries. American Chemical Society, 2023; DOI: 10.1021/jacs.3c04203