Life beyond lithium-ion: alternatives for electric vehicle batteries

Solid state batteries are emerging as the next power storage frontier for electric vehicles.
Published: Tue 27 Feb 2018

At least for electric vehicles (EV), the days of lithium-ion batteries are on the decline. Not tomorrow but probably within the next five to 10 years.

Lithium-ion limitations

While debate rages about the availability of lithium to meet the growing demand for batteries and companies such as Apple and Samsung start to recycle elements such as this, new technologies under development offer the potential to both undercut the cost of lithium-ion and to improve on its performance.

Based on data from the US Department of Energy, the Global EV Outlook 2017 found that “technologies currently in the R&D stage have better performance than those available on the market”. In addition, its assessment suggests that battery costs will continue to decline.

Beyond lithium-ion, technologies under development include advanced lithium-ion, using an intermetallic anode such as a silicon alloy-composite, and lithium metal combinations including aluminium-ion, lithium-sulphur and metal-air. Key issues include the capacity and cycle life that impact on the range and longevity from the user’s perspective.

Solid state batteries

While all of these technologies are under development in research labs, from the vehicle manufacturers’ perspective, the next major thrust is broadly termed solid state batteries. Several EV manufacturers are reported to be developing solid state options, including Honda, Hyundai, Nissan and Toyota.

In 2010 General Motors invested in the development of solid state batteries with the University of Michigan spun-out startup Sakti3, with the company subsequently acquired by vacuum manufacturing giant Dyson.

Initially, Dyson’s stated intent was to provide batteries for its own products but last year announced its plan also to roll out EVs starting in 2020.

BMW is another manufacturer which has started looking at solid state batteries in a December 2017 announced partnership with University of Colorado Boulder offshoot Solid Power.

Solid Power’s technology is based on combining a high capacity cathode with a high capacity lithium metal anode in combination with a high ionic conductivity solid separator. With all materials inorganic, there are no flammable or volatile components – unlike the liquid electrolytes of traditional lithium-ion systems.

As such, costly safety features can be eliminated. Other potential benefits include a greater energy capacity, faster recharge time and longer cycle life, all in a more compact design.

According to a statement on the deal, the BMW Group will assist Solid Power to advance its technology in order to achieve the performance levels required for high performance electric vehicles.

“Collaborating with BMW is further validation that solid state battery innovations will continue to improve electric vehicles,” comments Doug Campbell, Founder and CEO of Solid Power on the codenamed ‘xEV’ technology.

Beyond EVs

While the jury is still out on which of the emerging technologies will be the first to seriously challenge lithium-ion, the impact will extend beyond electric vehicles not only to portable electronic devices but also to aviation and shipping, where the power requirements become more significant.

This should be good for consumers, but also should speed the electrification of transport, which will help the world on its way to meeting the COP21 Paris Agreement.