Lithium-ion battery cells are currently dominant in electric cars and energy storage, but researchers are constantly looking to improve on them.
The need to increase the amount of electricity a battery can store, decrease charging times, and lower costs is driving experimentation with other battery chemistries.
Now, one British firm has found a somewhat unusual way to demonstrate its latest experimental chemistry.
Faradion was founded in 2011 to develop sodium-ion batteries, and as a proof of concept, it recently built an electric bicycle powered by them.
Replacing lithium with sodium could reportedly cut costs by about 30 percent per kilowatt-hour, because the material is more plentiful.
Faradion prototype electric bicycle powered by sodium-ion battery pack
However, sodium ions are also much larger than lithium ions, which makes the material less well-suited to use in battery cells.
By using a sodium-ion battery pack to power an electric bicycle, though, Faradion hopes to show how the chemistry can still work outside the lab.
The project was undertaken in concert with Williams Advanced Engineering, a division of the Williams Formula One team that also supplies batteries to the Formula E electric-car racing series.
It also did development work on the stillborn Jaguar C-X75 hybrid supercar.
Williams built the battery pack's four modules, each of which contains 12 cells. Everything is also controlled using a Williams-designed battery-management system.
Faradion sodium-ion battery
Because the bike is just a proof-of-concept exercise, the cells were made much larger than necessary to simplify the manufacturing process.
Fardion claims production-ready cells would be of comparable size to current lithium-ion cells.
Assuming researchers can achieve energy density similar to lithium-ion cells as well, the potentially cheaper sodium-ion cell could become an attractive option for future electric cars.
Of course, the usual disclaimer for new battery research applies here.
Success in the lab doesn't automatically translate into commercial viability and, even when it does, that process can take years to complete.