Maybe this is why we are not seeing much change in the batteries
http://www.wired.co.uk/article/what-is-solid-state-battery-toyota-dyson
Solid-state batteries are one of the technologies that could unlock the promise of electric cars. Toyota and Dyson are both known to be investing heavily in the technology, with the latter planning to launch a Dyson electric car in 2020.
According to a report in the Wall Street Journal earlier this year, Toyota has entered the production engineering stage of building a solid-state battery that would allow it to produce a smaller, lighter battery. Toyota also believes the new technology could be in electric vehicles by 2020.
How are they different to lithium ion batteries?
Lithium ion batteries are the standard batteries used in electric vehicles today. They have a relatively short useful life and are made from a flammable, organic solvent.
Dyson is ploughing £2.5bn into its own electric car
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Solid-state batteries contain solid electrodes and solid electrolytes, which have faster charging, increased energy density and cycle life, low leakage currents and are not flammable.
What does this mean for electric cars?
In theory, Toyota and Dyson can push the boundaries of electric vehicle design. Smaller batteries with longer battery life would allow them to focus on producing lightweight materials for other parts of the car and improving its efficiency. It would also allow them to increase the range.
The Wall Street Journal reports that the Japanese carmaker's use of a solid-state battery will increase the overall 'useable' life, which means a greater potential for product recycling after being used in the vehicle, such as in homes or commercial energy storage.
Toyota has been working towards all-electric vehicles for years now. In 2011 it said it was working with academic researchers to perfect crystalline structures that will move lithium ions through a solid electrolyte.
http://www.wired.co.uk/article/what-is-solid-state-battery-toyota-dyson