Battery breakthrough could bring electric cars to all

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A startup working on battery technology says it’s developed a key breakthrough that could one day lead to an electric car that has a 300-mile range and could cost around $25,000 to $30,000. Envia Systems, backed by venture capitalists, General Motors, and the Department of Energy, plans to announce on Monday at the ARPA-E conference that the company has created a lithium ion battery that has an energy density of 400 watt-hours per kilogram, which Envia CEO Atul Kapadia told me in an interview could be the tipping point for bringing electric cars to mainstream car owner.

The secret sauce

Energy density is how much energy a battery can store and provide for the car with a given battery size — the more energy dense the battery, the less volume and weight is needed. For electric cars it is particularly important to have a high energy dense battery because electric cars need to be as light weight as possible (any extra weight just drains the battery faster), and batteries that are smaller and use less materials can also be lower in cost.

Kapadia tells me that current lithium ion batteries deliver an energy density of around 100 to 150 watt-hours per kilogram, while Envia’s battery can deliver 2.5 times that energy with about the same weight as the current electric cars that have hit the market. To build a 300-mile range electric car with standard lithium ion batteries, it would cost around $40,000 just for the batteries alone, says Kapadia.

Envia says with an energy density of 400 watt-hours per kilogram, its battery cell costs could be at $125 per kWh. Tesla CEO Elon Musk has said recently that he sees battery cells dropping in price to below $200 per kWh in the coming years. Current electric cars like the Volt have been reported to be closer to $500 to $600 per kWh, and the Nissan LEAF at $375 per kWh.

Envia, founded in 2007 in the Palo Alto public library, began its business by developing technology for a low-cost cathode. A battery is made up of an anode on one side and a cathode on the other, with an electrolyte in between. For a lithium ion battery, lithium ions travel from the anode to the cathode through the electrolyte, creating a chemical reaction that allows electrons to be harvested along the way. After Envia developed its cathode technology, it started working on a silicon carbon anode, and then paired these two innovations together, with a high-voltage electroloyte.

Kapadia says the innovation is also important because many scientists have thought that the lithium ion battery had certain limits on how efficient and cheap it could get: “The rumors of the demise of lithium ion batteries are greatly exaggerated.”

Kapadia also says: “Gone are the days of relying on ancient consumer batteries for automobiles and stifling this revolution by making expensive electric cars.” And in case you didn’t get this reference, Tesla Motors uses small format standard lithium ion batteries like the ones found in laptops for its cars.

Getting the battery into cars

Charging up the Volt

Envia is announcing at the ARPA-E conference that it has reached this 400 watt-hours per kilogram milestone in tests, but the company is still in the prototype stage, and an Envia battery will probably take about three years to move into the commercial auto market. Envia plans to work with battery and auto partners, potentially licensing or creating joint ventures to get the batteries manufactured. Kapadia tells me that Envia plans to avoid the capital intensive model of trying to be a startup that does all its own manufacturing.

General Motors is one of Envia’s high profile investors, and invested $7 million into Envia about a year ago. GM has said that Envia will provide battery technology for future generations of GM’s Volt electric car. Other investors in Envia include Japanese giant Asahi Kasei, Pangaea Ventures, and Redpoint Ventures.

Envia received a $4 million grant from the DOE’s ARPA-E program to attempt to hit the 400 watt-hour per kilogram milestone. Expect Envia to be touted throughout the ARPA-E event, as proof that its program is working to develop green innovation in the U.S.

Images courtesy of Envia Systems.

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