Increasing Fuel Cell Efficiency via Phase Transition

Engineering researchers have gone small to make big changes in the effectiveness and long-lasting electrical strength of fuel cells by designing the electrolyte found in fuel cells on the quantum level. In doing so, the electrolyte material was made stronger and able to operate for longer upon exposure to the fuel.

The improved electrolyte is composed of perovskite-structured nickelate. Nickelate alone conducts both proton-like ions and electrons, which makes nickelate itself a poor electrolyte. However, an engineering research team from the Harvard John A. Paulson School of Engineering overcame this challenge by coating the surface of the nickelate with a catalyst. The coated nickelate was then injected with electrons and the injected electrons joined the electron shell of positive nickel ions.

As a result, the material was transitioned from an electron conductor to an ion conductor.

Engineering Better Fuel Cells

Fuel cells operate using a current which is generated by the flow of electrons between an anode and a cathode separated by an electrolyte. Fuel cells do not require recharging to operate. Instead, they require fuel, which is mostly composed of hydrogen.

The hydrogen from the fuel is fed to the anode and then split into protons and electrons. The electrolyte acts as a filter which blocks electrons and allows protons to enter. Electrons are then forced through an external circuit, which creates a flow of electricity.

Solid oxide fuel cells, which rely on low-cost ceramic materials, are among the most efficient and promising type of fuel cell. They work like batteries that don't need charging.

On the other side of the fuel cell, air is fed to the cathode. Protons flowing through the electrolyte and electrons moving through the external circuit meet the oxygen to produce water and heat—the only emissions produced by fuel cells.

This new development poses an important solution to a challenge currently faced by solid oxide fuel cells. As the cell ages, the fuel wears down the effectiveness of the electrolyte. As such, the electrolyte allows both protons and electrons to permeate through, causing the external electrical circuit to become increasingly weak.

The incredibly vast potential and applications of fuel cells make this development not only a researching feat, but also extremely useful for the alternative fuel industry.

Read more about the research in the journal Nature.