How Advanced Battery Technology and Lower Costs Are About to Disrupt the Electric Car Industry

How advanced battery technology and lower costs are about to disrupt the electric car industry

If car buyers haven’t hesitated over limited range and recharging infrastructure, the cars’ high upfront costs certainly has scared off many potential customers. Those high price tags are largely driven by the cost of the battery.

Not all batteries are expensive, however, lithium-ion batteries are. Automakers switched from nickel metal hydride batteries to lithium batteries in commercial EVs because lithium-ion battery technology enables cells with higher energy densities (kWh/kg), higher power densities (W/kg), significantly higher cycle life and greater safety than other battery chemistries. Currently, cost of these batteries is high, but it is expected that in- creased volume sales and technology improvements will significantly reduce the cost in the future.

“When you move into an all-electric vehicle,” Ford CEO Alan Mulally recently told a For- tune magazine forum on green technology, “the battery size moves up to around 23 kWh, [and] it weighs around 600 to 700 lbs. They’re around $12,000 to $15,000 [each]” in a compact car the size of a $20,000+ gasoline-powered Focus. “So you can see why the economics are what they are.”

Currently, customers pay about $520 per kWh for the batteries fitted to the electric Ford Focus, one of the more affordable vehicles available today. The price level the US Ad- vanced Battery Consortium is targeting for a fairly affordable electric car battery is about $125 per kWh. However, figures recently released by Lux Research, an independent research and advisory firm that focuses on emerging technologies, indicate that the low- est cost battery at the moment is produced by Tesla at $274 per kWh. On strength of scale and technology, Tesla aims at lowering the battery price by 30% to some $196 per kWh with the gigafactory – which is still too costly.

Unfortunately, these costs are not likely to drop any- time soon, ac- cording to Kevin See, lead analyst for the electric vehicle service of Lux Re- search: “The costs are too high and will remain so despite increasing economies of scale,” which bodes ill for widespread adop- tion of EVs in the near future. “We need innovations and new strategies to reduce the costs further, faster.”

One promising alternative would be a battery based on a multivalent ion, such as magnesium (Mg). Whereas a Li-ion with a charge of +1 provides only a single electron for an electrical current, a Mg-ion has a charge of +2, which means Mg-ions, in principle, can provide twice the electrical current of Li-ions if present in the same density.

Thus, a magnesium battery’s capacity is eight to 12 times higher than a lithium battery, and its charge-discharge efficiency is five times higher as well. Mg-ion batteries would also be safer and less expensive than Li-ion batteries. However, the additional charge on a multivalent ion creates other problems; the most notable being magnesium’s high reactivity with other materials in the battery which restricts the movement of the ions through the electrolyte.

New battery technology based on magnesium

This may soon change thanks to a new innovation recently unveiled by researchers from the National Cheng Kung University (NCKU) in Taiwan who have made significant strides in overcoming the inherent problems associated with magnesium-ion batteries. Fei-Yi Hung, one of the three leaders of the team, told the online publication Ener- gyTrends that they accomplished this in part by turning to a new technology that uses electrodes made of magnesium membranes and magnesium powder.

To illustrate magnesium’s superiority over lithium, Hung explained that an electric bicy- cle with a fully depleted lithium-ion battery needs about three hours to recharge fully, but if equipped with a magnesium battery the process would take a mere 36 minutes.

Also, the team claims that if current lithium batteries were to be coated with a film of magnesium, they would be capable of operating at temperatures as low as -30°C (Cur- rent lithium technology looses efficiency at around -15°C) and as high as 55°C.

Possibly even more impressive than the improvements made to magnesium batteries, are the claims that a Michigan startup company has developed an advanced solid state Li-ion battery that overcomes two of the major obstacles faced by current generation electric vehicles: 'range anxiety' and 'affordability'.

Sakti3 - Disrupting the electric car industry

Michigan battery company Sakti3, a spinout of the University of Michigan, which is fi- nanced by the world’s top cleantech fund, Khosla Ventures, and the world’s largest automotive investor, General Motors Ventures, claims that the company's solid state battery will be able to double the range of an electric car. The solid state batteries would enable a vehicle like the Tesla Model S to travel 800Km on a single charge.

Not content with overcoming the 'range anxiety' challenge for electric vehicle users, the Michigan startup also claims it will be able to produce the batteries commercially for around $100 per kilowatt hour which halves the figure currently achievable by lithium ion

batteries, and is a considerable improvement on the US Advanced Battery Consortium’s target of about $125 per kWh.

In September Sakti3's founder Ann Marie Sastry revealed the energy density for the company's latest battery cell to be 1100 watt hours per liter. Whilst the energy-density claims have yet to be independently verified, Sakti3 became an affiliate of the US De- partment of Energy's Joint Center for Energy Storage Research (JCESR) in March 2014. As far back as 2006 Sastry and her colleagues started working on complex math- ematical optimization systems to find out which of the many variables that make up an electric car battery - energy, power, mass, volume, cost, safety - could give the best re- sults. The calculations pointed to the need to remove the liquid electrolyte found in con- ventional lithium-ion batteries together with all of the extra packaging that this liquid electrolyte requires.

The vacuum deposition process used to manufacture the battery cells requires that the layers of the thin-film battery are deposited sequentially - first for the cathode, then the current collector, then the interlayer, anode and such like. The innovative technology enables a solid-state battery to be produced with a similar thin-film deposition process used to make flat panel displays and photovoltaic solar cells.

The test packs have been made on 'fully scalable equipment', with Sastry indicating that the technology would be available for sale within two years, targeting wearable electron- ics before moving on to address the automotive sector. With Li-ion technology being seen as the baseline against which all EV battery development is measured Japanese start-up, Power Japan Plus, recently launched a new battery technology that claims to offer a more sustainable, safer, longer-lasting and cost-effective battery with an energy density comparable to a lithium ion battery whilst charging 20 times faster.

Dual carbon battery utilizing unique chemistry

Power Japan Plus is a materials engineering company that has developed a new class of carbon material that balances economics, performance and sustainability in a world of constrained resources, said Dou Kani, CEO of Power Japan Plus. Current advanced batteries have made great improvements on performance, but have done so by com- promising on cost, reliability and safety said CTO, Dr. Kaname Takeya, claiming that the Ryden dual carbon battery is the energy storage breakthrough needed to bring green technology, such as electric vehicles, to mass market, while balancing consumer de- mands, including performance, cost, reliability, safety and sustainability.

The Ryden dual carbon battery, developed in partnership with Kyushu Universi- ty in Fukuoka Japan, claims to be the first high performance battery that meets a consumer lifecycle demand rated at more than 3.000 charge/discharge cy- cles.

The battery also claims to be the safest high performance battery chemistry ever. By eliminating the unstable active materials used in other high performance batteries, fire and explosion hazards are greatly reduced, while the battery undergoes minimal tem- perature change during operation, eliminating the threat of a thermal runaway.

The new battery is capable of slotting directly into existing manufacturing processes, re- quiring no change to existing manufacturing lines. Even more importantly, the battery allows for consolidation of the supply chain, with only one active material, carbon. This reduces any threat of supply disruption or price spikes from rare metals, rare earth or heavy metals.

The battery, which can be completely charged and discharged with no damage to the cells, is 100 percent recyclable thereby vastly improving the cradle-to-cradle sustainability. Tests are currently being conducted using the company’s organic Carbon Complex material, with the intention of producing the battery with all organic carbon in the future.

Power Japan Plus began benchmark production of 18650 Ryden cells toward the end of 2014 at the company’s production facility in Okinawa, Japan. The facility will allow the company to meet demand for specialty energy storage markets such as medical devices and satellites. For larger demand industries, such as electric vehicles, licensing agree- ments will be entered into that will provide technology and expertise to existing battery manufacturers.

Beyond the dual carbon battery, Power Japan Plus is creating a new, drop-in material with the world’s first and only organic carbon material, Carbon Complex. Made of natu- rally grown organic cotton, Carbon Complex claims to offer novel properties not seen in other carbon material. By controlling the size of the carbon crystals during production, Power Japan Plus can engineer the Carbon Complex for a variety of high performance applications.

Battery Cost Studies

Over the past a wide range of battery cost studies have been performed but usually different studies make different assumptions leading to all kind of cost projections. Some studies use ground up models that cost out all the specific components of the battery pack while others use top down methods to estimate overall cost. The following graphs show the varying perspectives of decreasing battery pack costs for both full battery EVs and Plug-in hybrid vehicles.

Pack cost Forecast:

Source: Edison Electric Institute (EEI), 2014 / Analysis by UC Davis

Plug-in hybrid vehicle forecast:

Source: Edison Electric Institute (EEI), 2014 / Analysis by UC Davis

Author: Peter Els

AutoRenew – Battery Technologies and Energy Storage Solutions 28-30 September 2015, Berlin

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