Zinc-air batteries: a cheaper, safer alternative to Li-ion

Batteries built from zinc and air could be the future of powering electric vehicles, according to research from Edith Cowan University (ECU). Researchers tested zinc-air batteries using cheaper, safer and sustainable sourced materials, which allowed for improved lifespan and performance. Zinc-air batteries could be a better alternative to lithium for the advancement of sustainable battery systems.

ECU’s Dr Muhammed Rizwan Azhar led the project, which discovered that lithium-ion batteries face limitations related to cost, finite resources and safety concerns. “Rechargeable zinc-air batteries (ZABs) are becoming more appealing because of their low cost, environmental friendliness, high theoretical energy density and inherent safety,” Azhar said.

The emergence of next-generation long-range vehicles and electric aircraft in the market has increased the need for safer, more cost-effective and high-performance battery systems that can surpass the capabilities of lithium-ion batteries.

A zinc-air battery consists of a zinc-negative electrode and an air-positive electrode. The major disadvantage of these has been the limited power output, due to poor performance of air electrodes and a short lifespan. ECU’s research has enabled researchers to use a combination of new materials, such as carbon, cheaper iron and cobalt based materials, to redesign zinc-air batteries.

“The new design has been so efficient it suppressed the internal resistance of batteries, and their voltage was close to the theoretical voltage, which resulted in a high peak power density and ultra-long stability. In addition to revolutionising the energy storage industry, this breakthrough contributes significantly to building a sustainable society, reducing our reliance on fossil fuels and mitigating environmental impacts,” Azhar said.

The use of natural resources such as zinc and air further enhances the cost-effectiveness and viability of the zinc-air batteries for the future. Azhar said while renewable resources such as solar, wind and hydro energy play a role in the future of green energy, they are not completely reliable solutions as they are intermittent sources of energy. “Due to the abundance of zinc available in countries such as Australia, and the ubiquity of air, this becomes a highly viable and reliable energy storage solution,” Azhar said.

Image credit: iStock.com/HT Ganzo