Chevrolet Spark EV at CCS fast charging station in San Diego.Enlarge Photo
All electric vehicles currently in production use some form of lithium-ion chemistry in their battery packs.
Finding ways of improving that chemistry is therefore very important--the aim being to make future electric car batteries cheaper, more stable and more energy-dense for longer range.
Researchers from the School of Engineering at the University of Tokyo have found a way to develop a lithium-based battery with seven times the energy density of current lithium-ion batteries, according to Nikkei Technology.
This has, at least theoretically, each of the major benefits you'd expect should it be introduced in production form--lower cost, greater capacity and increased safety.
Led by Professor Noritaka Mizuno, the team have used a new material on the positive electrode in the battery, formed by adding cobalt to the lithium oxide crystal structure. This aids an oxidation-reduction reaction during which peroxides are produced, and electrical energy is generated.
The researchers claim energy density of 2,570 watt-hours per kilogram. That's actually a little less than the theoretical density of lithium-air technology (3,460 Wh/kg, and a current leader in lithium battery developments) but as a sealed design it's more stable (and therefore safer) than lithium-air.
The team also proved that there are no unwanted byproducts in the battery's acceptable charging and discharging cycle--no excess oxygen or carbon dioxide is produced during the reactions.
Tests at the university have also shown it's possible to repeatedly charge and discharge the battery at a large current, boding well for faster charging.
In theory, at least. As with all current battery research projects, there is still some way to go before the technology can be applied in a practical format--one that could be used in electric vehicles.
While the team mentions no apparent drawbacks, such a concept would require more thorough testing before it's applied inn the real world. As ever though, it's evidence that battery technology is still progressing behind the scenes--and that one day, electric cars should be able to travel much further on a charge.
[Hat tip: Hugh Crawford]