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Saturday, May 17, 2014

Electric Vehicles: New Dual-Carbon Batteries Potentially Better Than Lithium-Ion

As reported by Green Car Reports: In the search for better electric-car batteries, lots of lab research has to happen before anything can be announced.

A company called Power Japan Plus came out of stealth mode to unveil a new battery chemistry, with both electrodes--anode and cathode--made of carbon.

The new cell, known as the Ryden Dual-Carbon Battery, promises energy density equal to today's lithium-ion cells, but less capacity loss over time and far greater safety.

Power Japan Plus - Dual-Carbon Battery vs Lithium-Ion Battery
Dual-Carbon Battery vs Lithium-Ion Battery
Same energy, longer life, safer, recyclable
It is also almost entirely recyclable, with less energy input over its lifetime--and none of the rare or heavy metals required in various lithium-ion cell chemistries.

Dual-carbon cells have been described in theory since at least 1978, but years of development were required to make them reliable, cost-effective, and suitable for mass production in high volumes, Power Japan Plus CEO Dou Kani told Green Car Reports.

The breakthroughs in chemistry were achieved by chief technology officer Kaname Takeya and Dr. Tatsumi Ishihara of Kyushu University in Fukuoka, Japan, which partnered with the company to develop the cell for commercial applications.

While they cannot provide details due to multiple pending patents, Takeya said that the chemistry requires specific and proprietary changes to the nanostructure of the carbon crystals.

While Power Japan cannot disclose its first customer today, CEO Kani said, it will announce a partner in August, that will build battery packs and add a battery-management system.

Power Japan Plus - energy capacity over cycle life
Energy capacity over cycle life: Power Japan Plus
What electric cars need to succeed?
The company isn't holding back the hyperbole.
“The Ryden dual-carbon battery is the energy storage breakthrough needed," said CEO Kani, "to bring green technology like electric vehicles to [the] mass market.”

With energy density comparable to lithium-ion, the company claims that its Ryden dual-carbon chemistry can both recharge up to 20 times as fast and deliver more than 4 Volts of power from a single cell.

In testing, the cell has completed more than 3,000 charge/discharge cycles with virtually no performance degradation, meaning that it could conceivably last the lifetime of a car.

Power Japan says a Ryden cell barely heats up during charge and discharge--it "experiences minimal thermal change"--vastly reducing the risk of thermal runaway that can lead to explosion and fires.

Power Japan Plus - energy capacity over cycle life
Energy capacity over cycle life: Power Japan Plus
In other words, an electric car's battery would hold its full energy over 10 years or more, and could be discharged right down to 0 percent of capacity without damage.

New chemistry, same production process
And equally important for practicality, the new dual-carbon anode and cathode can both be produced by existing cell manufacturing processes--and require essentially just a single material as input: carbon.

That reduces the number of materials that must be procured for the supply chain, simplifying the entire production process.

Power Japan Plus says it will start production of Ryden cells in the 18650 "commodity cell" format later this year at its small production facility in Okinawa, Japan.

Satellites first
Those cells will be intended for low-volume specialty markets, including satellite and medical-device energy storage--in volumes of 500 to 5,000 cells per month.

For higher-volume production intended for other markets--including plug-in electric cars--the company will license its technology and consult with existing battery makers to enable them to produce the anode and cathode materials in their own facilities.

The next announcement will be a partnership with a "world-renowned company" in the auto racing field, which will build packs and complete battery systems, test them, and offer them in the market.

Power Japan Plus - Carbon Complex carbon made from organic cotton
Comblex carbon made from organic cotton - Power Japan Plus
Separate from the announcement of the Ryden battery, Power Japan Plus is also working on a new form of carbon that is entirely organic.

The material, known as Carbon Complex, which is made using naturally-grown organic cotton that is then processed using special techniques to control the size of the carbon crystals formed during production.

Early test cells are not produced with the organic carbon, but the company's goal is to create a battery cell that is not only competitive with today's lithium-ion cells but uses entirely organic input materials that can be fully recycled at the end of their life.

Meanwhile, Power Japan Plus--which has been internally funded until now--is seeking its first investments of private funds.  And, we suspect, car companies all over the globe will already be making plans to acquire some of the earliest Ryden dual-carbon cells to see if they hold up to the company's claims under independent testing.

Lithium-ion cells are likely to remain the default battery chemistry for electric cars at least through the end of the decade.

But the Power Japan Plus announcement--along with other potentially promising advances in lithium-air cells and other advanced chemistries--show the vital importance of battery technology to the future of transportation.