According to Technology Review, a British defense technology company, Qinetiq, is testing a new type of lithium-ion battery for hybrids and electric vehicles that could be cheaper and more powerful than existing batteries.
The battery is based on lithium-ion iron-sulfide chemistry, which has a number of advantages over the chemistry of existing batteries, says Gary Mepsted, technical manager for Qinetiq’s power sources group. The new battery would cost half as much as existing vehicle batteries and could last longer and recharge more quickly that other lithium batteries. Mepsted says that compared to standard lithium-ion batteries, the new battery has demonstrated about 1.6 times the energy density and a 50 percent higher power density.
Qinetiq’s approach involves making cathodes from lithium-ion iron sulfide instead of the more common lithium-cobalt oxide. Because this chemistry results in two lithium ions for every sulphide, it creates a massive increase in energy density.
Cost is a major issue, says Dahn. “Batteries are about three to five times more expensive than what we want,” he says. But while there are energy and cost advantages to using iron sulfide, it can be problematic to use in manufacturing. “Iron sulfide is stable in air, but when you react it with lithium it loses this stability,” he says.