Fuel cells were invented in 1839, powered the Gemini and Apollo space missions, and still provide power on the space shuttle. But perfecting them for use in cars still poses a challenge. Scientists at the Laboratory are developing new materials to make fuel cells cost-effective, durable, and vehicle-ready.
One day soon, these highly efficient powerhouses could replace internal combustion engines, so that our cars burn less fuel, and give off nothing more than the harmless emission of ordinary water.
The United States consumes much more oil than we produce domestically. In 2007, the U.S. produced 5.1 million barrels of oil per day, but consumed 20.7 million barrels per day according to the Energy Information Administration, which provides energy statistics from the U.S. government. The result is that the U.S. imports significant amounts of oil, and is dependent upon foreign countries for its oil supply.
Fuel cells, which utilize hydrogen instead of gasoline or diesel fuel, would greatly reduce that dependence.
Fuel cells are similar to batteries; they convert chemical energy
into electricity. However, unlike batteries, fuel cells use chemicals
that are external to the fuel cell. The types of fuel cells LANL
scientists develop convert hydrogen and oxygen (from air) into
electricity and water. The system utilizes a thin membrane and
catalysts - often made of platinum - to electrochemically convert the
hydrogen and oxygen into electricity.
"Of course, environmentally we love fuel cells because hydrogen plus oxygen makes water," says Rod Borup, program manager for the Laboratory's fuel cell program in MPA-11, the Sensors and Electrochemical Devices Group.
Scientists at the Lab are developing better materials and technologies to improve the different components of the fuel cell. These improvements include decreasing the costs of the catalyst, improving the materials that make up the membranes, understanding what degrades the performance of fuel cells including the effects of fuel and air impurities, understanding water management inside the cell, and improving on-board vehicle hydrogen storage.
One of the biggest advantages of fuel-cell powered vehicles is their
efficiency as compared to conventional internal combustion engines.
A gasoline-powered engine is about 22 percent efficient, Borup says. That means that 22 percent of the fuel you put into your car is used to power the vehicle, and the remainder is wasted as heat. A diesel-powered vehicle runs at about 27 percent efficiency, a hybrid electric vehicle, about 30-35 percent.
By contrast, fuel cell vehicles can run at 55 percent efficiency. They simply burn less fuel.