Scientists at the Institute of Materials Science of Barcelona (ICMAB-CSIC) have unveiled a new battery architecture that could significantly enhance the performance of zinc-air batteries, a promising technology for sustainable energy storage. By inserting small conductive elements inside the battery, the team achieved a power output increase of up to 80% without altering the underlying chemistry.
The findings, published in the journal Energy Storage Materials, challenge long-held assumptions about battery design and open new avenues for developing more efficient storage systems. The research was conducted in collaboration with the Catalan Institute of Nanoscience and Nanotechnology (ICN2) and the National University of La Plata in Argentina.
A design principle that rewrites the rules
Conventional batteries generate electricity by exploiting the energy difference between two electrodes. Charges flow from one electrode to the other through an electrolyte, a material that conducts ions but was traditionally thought to block electrons to prevent short circuits. The new study, led by ICMAB-CSIC researcher Nieves Casañ-Pastor, demonstrates that this assumption is not always necessary.
The team showed that under certain conditions, small pieces of conductive metal can be placed inside the battery without being connected to either the electrodes or the external circuit. Rather than causing a short circuit, these isolated conductors improve performance. The electric field generated between the electrodes during operation polarises the conductive pieces, causing them to accumulate opposite charges at their ends. This creates new pathways for charge transport, reducing internal resistance and allowing energy to be delivered more quickly.
“What is remarkable is that these conductors are not wired to anything: they are simply inserted into the system and they produce beneficial effects,” Casañ-Pastor explained.
The oxygen challenge
Zinc-air batteries are made from abundant, inexpensive, and safe materials, but their performance has been limited by the slow reaction of oxygen at the cathode. The new design addresses this bottleneck by incorporating wireless bipolar electrodes that reduce internal resistance and speed up energy delivery, enabling the power boost.
The research, part of Marc Mosqueda's doctoral thesis, highlights the potential of this approach for other battery technologies. Casañ-Pastor noted that the group has already observed similar effects in other systems and plans to continue investigating the potential of wireless bipolar electrodes.
This breakthrough comes at a time when Europe is seeking to bolster its energy storage capabilities, particularly for renewable energy integration. The work by Spanish researchers could contribute to more efficient and cost-effective storage solutions, aligning with broader EU goals for a green transition.
While the technology is still in the research phase, the implications are significant. If scaled up, zinc-air batteries with this new design could offer a viable alternative to lithium-ion batteries for certain applications, reducing reliance on scarce materials and improving sustainability.
The study also underscores the importance of fundamental research in driving innovation. As Casañ-Pastor and her team continue to explore the potential of wireless bipolar electrodes, the scientific community will be watching closely for further developments.
