Tesla Motors, the maker of high-performance electric vehicles, is working with Panasonic, the battery and consumer electronics giant, to develop its next generation of batteries. The partnership is intended to help Tesla lower the cost of its batteries and improve the range of its vehicles.
Last month Panasonic announced two high-energy batteries for electric vehicles. These new batteries store as much as 30 percent more energy than its previous lithium-ion batteries, and this increased storage could, in theory, increase a vehicle’s range by a similar amount, thereby addressing one of the main problems with electric cars. Tesla’s Roadster currently has a range of 244 miles and takes three and a half hours to charge with a special charger.
The other major challenge with electric vehicles is the cost of the battery packs. Tesla isn’t announcing the potential cost savings with future batteries, but JB Straubel, Tesla Motor’s chief technology officer, says battery costs have been steadily declining at about 8 percent a year.
Tesla plans to incorporate Panasonic’s cells into its battery packs, and will work with Panasonic to develop cells fine-tuned for use in cars, Straubel says. To do this, Tesla will draw on data gathered from the 1,000 cars it has made so far, which have been driven for over a million miles. Tesla currently gets its batteries from a variety of manufacturers.
Those driving Tesla cars won’t immediately see the added range from the new high-energy battery cells, Straubel says, since there is a lengthy process for validating the performance of new cells. What’s more, the actual range increases can vary. (For example, electronic controls keep a battery from completely discharging to help improve safety and reliability–complete discharges can harm some battery materials. The way the battery is controlled depends upon its chemistry and other details of the cell design.)
One of the new cells in particular will require extensive testing, since it relies on silicon-based electrodes. In theory, silicon electrodes can hold much more energy than the carbon electrodes they replace, but silicon electrodes tend to swell and break apart. They’ll need to be tested to make sure these problems have been overcome.