Researchers at the Institute of Materials Science of Barcelona (ICMAB-CSIC), working with the Catalan Institute of Nanoscience and Nanotechnology (ICN2) and the National University of La Plata in Argentina, have developed a zinc-air battery architecture that increases power output by up to 80% without changing its core chemistry.

The work, “Unlocking high power in membraneless Zn-air batteries: A paradigm shift via wireless bipolar electrochemistry,” was published in August in Energy Storage Materials. It challenges the conventional approach of avoiding conductive materials in the electrolyte to prevent short circuits. In the new architecture, conductive elements remain disconnected from the external circuit, while their polarization under an electric field reduces internal resistance rather than causing a short circuit.

The architecture introduces small conductive elements inside the battery that are not connected by wires to either the main electrodes or the external circuit. These elements act as wireless bipolar electrodes and modify the distribution of charge within the device.

The principle relies on the electric field that develops between the two electrodes while the battery is operating. When an electrically isolated conductive element is introduced into the electrolyte, the field polarizes it, causing one end to become positively charged and the other negatively charged. The element thereby creates additional pathways for charge transport without establishing a direct electrical connection between the electrodes.

The effect is particularly relevant to zinc-air batteries, in which the electrochemical reaction involving oxygen limits the rate of operation. Zinc has a favorable oxidation reaction and the system uses aqueous chemistry, while the oxygen reaction is slower and can limit the power the device can deliver.

Source link