New zinc-air battery design boosts power output by up to 80% using wireless bipolar electrodes

In Spain, researchers at the Institute of Materials Science of Barcelona (ICMAB-CSIC) have developed a new architecture for zinc-air batteries that can boost their power output by up to 80% without changing their core chemistry. The system integrates conductive elements inside the battery, which act as wireless bipolar electrodes to ease charge transport and reduce internal resistance.

The breakthrough opens up a new way of designing more efficient, higher-performance batteries. The study, published in the journal "Energy Storage Materials", was carried out in collaboration with the Catalan Institute of Nanoscience and Nanotechnology (ICN2) and the National University of La Plata in Argentina.

According to the researchers, this work and previous studies by the group challenge the conventional design of batteries and point to a new way of thinking about energy storage systems.

A design principle that changes the rules

Batteries generate electricity thanks to the energy difference between the materials in their two electrodes. Charges move from one to the other through the electrolyte, a material that allows ions to move. Until now, it was assumed that this component had to block the flow of electrons to avoid any risk of short circuit. The new study calls this principle into question.

The team led by Nieves Casañ-Pastor, a researcher at ICMAB-CSIC, has shown that, under certain conditions, small conducting metal pieces can be placed inside the battery without being connected either to the electrodes or to the external circuit, and that doing so can even improve its performance.

The key lies in the electric field that forms between the two electrodes when the battery is operating. The researchers have found that inserting one or more isolated conductive elements between them does not cause a short circuit and can help improve charge transport.

The electric field polarises the conductive pieces, which accumulate opposite charges at their ends and create new pathways for charge transport. This reduces internal resistance and makes it possible to deliver energy more quickly. "What is surprising is that these conductors are not wired to anything: they are simply introduced into the system and produce beneficial effects," Casañ-Pastor explains.

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The oxygen challenge, the key to the new design

The research, which forms part of Marc Mosqueda's doctoral thesis, demonstrates the potential of zinc-air batteries, made from abundant, cheap and safe materials, but limited by the slow reaction of oxygen.

The new design incorporates wireless bipolar electrodes that cut internal resistance and speed up energy delivery, allowing power output to increase by up to 80%.