Solid carbon fuel cells promise efficiency boost

The group’s fuel cell design, which is described in the journal Advanced Materials incorporates innovations in three components: the anode, the electrolyte and the fuel which allow the fuel cell to utilise about three times as much carbon as earlier direct carbon fuel cell (DCFC) designs.

The new fuel cells also operate at lower temperatures and showed higher maximum power densities than earlier DCFCs, according to INL materials engineer Dong Ding.

Whereas conventional hydrogen fuel cells generate electricity from the chemical reaction between pure hydrogen and oxygen, DCFCs can use any number of carbon-based resources for fuel, including coal, coke, tar, biomass and organic waste.

Because DCFCs make use of readily available fuels, they are potentially more efficient than conventional hydrogen fuel cells. "You can skip the energy-intensive step of producing hydrogen," Ding said.

Earlier DCFC designs have faced several drawbacks, not least the fact that they require temperatures of up to 900 degrees Celsius—which makes them less efficient and less durable and means they have to be constructed of expensive materials that can handle the heat. What’s more, early DCFC designs aren't able to effectively utilise the carbon fuel.