Could urea be used to create electric vehicle batteries?

Researchers from Adelaide University’s School of Chemical Engineering have identified a new way to create an important chemical in energy storage by using urea.

Hydrazine, the chemical in question, is widely used in a variety of industries including pharmaceuticals and rocket fuels, as well as emerging energy systems and electric vehicle batteries.

“Hydrazine is industrially synthesised from ammonia or a derivative urea created through an established method,” said Dr Pengtang Wang.

“These methods have been developed and employed for decades, but they rely on other hazardous chemicals, and use a great deal of energy, which makes it costly and environmentally challenging. Developing a new and mild alternative to this conventional process would represent an important step towards greener and more economical hydrazine production,” Wang said.

The research team created an electrochemical strategy which converted urea into hydrazine using electricity and sodium chloride, with findings published in the journal Nature Synthesis.

“Urea was chosen as the feedstock because it is abundant in human urine,” Wang said.

“Turning this readily available resource into hydrazine could provide a potential pathway for fuel production, including applications in fuel cells and long-duration space missions. Sodium chloride helps drive the reaction by generating adsorbed chlorine species on the electrode surface. These chlorine species react with urea to form N-chlorourea, which is then converted into hydrazine through a simple hydrolysis process,” Wang said.

Using this strategy, the researchers achieved high-yield hydrazine production and demonstrated its versatility across different urea sources, including pure urea, urea-rich wastewater and human urine.

“Although this electrochemical strategy enables efficient urea-to-hydrazine conversion, practical engineering challenges and associated cost bottlenecks, including salt accumulation and energy consumption required for product isolation, remain to be addressed,” Wang said.

“Future research will focus on reducing costs, simplifying product separation, improving continuous system operation and developing more practical reactor designs. With these engineering advances, we believe this technology could provide a sustainable alternative route for hydrazine manufacturing powered by renewable electricity.” Wang said.

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