Research staff at the Barcelona Institute of Materials Science (ICMAB) of the Spanish National Research Council (CSIC), an organization under the Ministry of Science, Innovation and Universities, have developed a new architecture for zinc-air batteries capable of increasing their power output by up to 80% without modifying the device’s main chemistry. The strategy involves incorporating conductive elements inside the battery, where they act as wireless bipolar electrodes that facilitate charge transport and reduce internal resistance.
The breakthrough offers a new way to design more efficient, high-performance energy-storage systems. The research, published in the journal Energy Storage Materials, was carried out in collaboration with researchers from the Catalan Institute of Nanoscience and Nanotechnology (ICN2) and the National University of La Plata (Argentina). This paper, together with previous work by the group, completely changes the way battery design has traditionally been conceived.
An Idea That Challenges Traditional Rules
A battery stores energy through the energy difference between the two materials that make up its two electrodes. Electricity is generated as charges move from one material to the other through a third intermediate material, the electrolyte, which allows electrically charged atoms or molecules, known as ions, to move. However, electrolytes have never been designed to transport electrical charge in the form of electrons. This long-standing assumption is what the new study calls into question.
Traditionally, it has been assumed that the electrolyte should transport ions without containing conductive materials because, in theory, any material capable of transporting electrons could cause a short circuit, causing the battery to stop working. To prioritize safety, all battery designs have therefore been based on the principle that electrolytes should not contain conductive materials.
Now, the team led by ICMAB-CSIC researcher Nieves Casañ-Pastor has demonstrated that, under certain conditions, introducing small conductive metal pieces that are not connected by wires to the external circuit or to the electrodes can have beneficial effects.
When the battery is operating, an electric field is created between its two electrodes. The research team discovered that, if one or more small, unconnected conductive pieces are placed between them, they do not cause a short circuit.
On the contrary, the electric field causes one end of the piece to accumulate positive charge and the other end to accumulate negative charge—a phenomenon known as polarization. This polarization creates new pathways for charge transport within the battery and facilitates the electrochemical reactions that generate electricity. The result is lower internal resistance and a battery capable of delivering energy more rapidly.
“Normally, if a material could transport electrons within the electrolyte, you would have a short circuit and you would no longer have a battery,” says Casañ-Pastor. “What is surprising is that these conductors are not connected by wires to anything: they are simply placed inside the system and, even so, they produce beneficial effects and enormous changes in power or charging capacity.”
More Power from Abundant Materials
The research forms part of the doctoral thesis of Marc Mosqueda, who recently completed his PhD at ICMAB. Much of this work focused on inducing these effects in various types of batteries. The main advantage of the zinc-air system is that it uses abundant, inexpensive, and safe materials. However, it also has some drawbacks: the reaction with oxygen is relatively slow, which limits the power the battery can deliver. The new design demonstrates its potential to overcome this limitation by facilitating charge transport and significantly increasing system performance.
In zinc-air batteries, “zinc oxidizes very easily, it is not dangerous, and the system’s aqueous chemistry prevents the battery from exploding as can happen with lithium batteries or other materials. On the other hand, the reaction involving oxygen is slow. It is a very stable compound,” explains Casañ-Pastor. The solution designed by Casañ-Pastor and Mosqueda introduces wireless bipolar electrodes inside the battery, significantly reducing the system’s resistance and increasing the rate at which it can deliver energy. The result is a notable increase in performance and an improvement in power of up to 80%.
An Opening for a New Generation of Batteries
For Casañ-Pastor, the main value of the work extends beyond the battery studied: “This is not the definitive solution, but rather a new avenue for improving different performance parameters of a battery,” she says. The group has already observed similar effects in other energy-storage technologies and will continue exploring new applications of this architecture based on wireless bipolar electrodes.
Article
Mosqueda, M., Bengoa, L., Goñi, S., & Casañ-Pastor, N. Unlocking high power in membraneless Zn–air batteries: A paradigm shift via wireless bipolar electrochemistry. Energy Storage Materials, 2026, Volume 90, August 2026, 105418. DOI: 10.1016/j.ensm.2026.105418
