Chinese researchers develop membrane for alkaline fuel cell

Researchers at Wuhan University in Wuhan, China, have developed a new membrane for fuel cells that operates in alkaline conditions, opening up the possibility of using cheaper catalysts.

The prototype fuel cell uses nickel as a catalyst instead of platinum. The model currently has low power output, but the researchers call the findings the first step to developing low-cost hydrogen fuel cells.

Fuel cells use catalyst-coated electrodes to split hydrogen into ions and an electrical current. The membrane conducts acidic hydrogen ions between the electrodes to create the external electric current.

Wuhan's alkaline fuel cell can use cheaper metals for catalysts because the conditions are less harsh. The prototype reacts hydrogen and oxygen to create hydroxyl ions and water using a nickel anode catalyst. The polymer membrane developed by the Wuhan researchers then conducts hydroxyl ions to generate an external electrical current.

The power output of the fuel cell is about 50 milliwatts per square centimeter at 60 degrees Celsius.

Other scientists are developing ways to remove pricey platinum from fuel cells.

Last year, Japans' Daihatsu Motor said it developed a method to use alkaline instead of acid exchange membranes to enable the use of less-costly metals, such as cobalt or nickel (see Daihatsu makes platinum-free fuel cell).

In October, India’s National Chemical Laboratory said it developed a polymer that could be 100 times cheaper to use than the industry-standard material for building hydrogen fuel cells. The substance is a variant of polybenzimidazole, which is used in making spacesuits (see India makes cheaper fuel cell part).

And in Japan, researchers say they've developed a smaller, cheaper fuel cell that can also generate power at room temperatures (see Japanese tout low-temp fuel cell). The researchers’ fuel cell uses a membrane composed of polybenzimidazole doped with phosphoric acid, allowing protons to migrate through the phosphoric acid.

Lin Zhuang led the team of researchers at Wuhan University in developing the polymer, which is structurally comparable to the highly conductive polymer Nafion that's used in conventional acidic fuel cells. Nafion is a polymer trademarked by Wilmington, Del.-based DuPont (NYSE: DD) used for the proton exchange membrane of the fuel cell, allowing ions to move from one side of the cell to the other.

Source: Cleantech.com