“The number one problem has been the cost. Seventy percent of lithium-ion cell [cost] comes from materials. Overall, 40 percent of the cost is the cathode alone,” said Envia co-founder and CTO Sujeet Kumar. “The cathode is the costliest component. If you want to reduce the cost of the lithium-ion battery, the first thing you want to reduce is the cost of the cathode.”
In 2007, Kumar began investigating new cathode technologies, hoping to identify a low-cost, energy-dense innovation. After reviewing the academic literature, he settled on a manganese-based chemistry created at Argonne National Laboratory. Envia licensed the technology, and then set to optimize cathode chemistry.
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“The bottleneck [became] the anode. That is what ARPA-E funded. That was our proposal,” said Kumar. “We had a very good working cathode. If you [could] pair it up with an anode, you [would] end up with a 400 wh/kg battery.”
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But before Envia’s battery can be commercialized in electric vehicles, it must also meet cycle life requirements, satisfy safety standards, and undergo qualification.
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Numerous other start-ups are exploring both lithium-ion advances and alternative chemistries. Boston-Power recently raised capital from Chinese investors to manufacture advanced lithium-ion batteries. QuantumScape is a stealthy start-up backed by both Khosla Ventures and Kleiner Perkins Caufield & Byers. ARPA-E also funded Sion Power, Pellion Technologies, and PolyPlus, which are developing lithium-sulfur, magnesium-ion, and lithium-air batteries, respectively.
“Quite frankly, some of the other companies [we funded] are close [to 400 wh/kg],” said ARPA-E’s Boysen. “Our job is to bring not one, but many technologies across the finish line.”