Lithium-ion batteries have come a long way, but in many ways they haven’t come far enough.
They charge faster than ever before, but there’s still room for improvement. The materials they’re made of, particularly cobalt and nickel, are pricey and problematic. Researchers have been scrambling to find alternative materials, from manganese to sodium. Now they might have another: TAQ.
Unlike nearly every other lithium-ion battery chemistry, TAQ is an organic compound — not the free-range hippie type, but the kind made primarily of carbon. Researchers have been investigating organic materials as cathodes, the negatively charged part of the cell, because they could store more energy at lower cost. But so far, candidate materials haven’t been very durable because they tend to dissolve in the liquid electrolytes commonly used in the industry today.
The new material doesn’t dissolve in two widely used electrolytes, and it sports an energy density that’s 50% better than one of the most common lithium-ion battery chemistries in use today, nickel-manganese-cobalt (NMC).
TAQ, short for bis-tetraaminobenzoquinone, is composed of carbon, nitrogen, oxygen and hydrogen arranged in a row of three neighboring hexagons. The structure is similar to that of graphite, which is almost universally used today as an anode material (the positive terminal). Each TAQ molecule is attracted to up to six others through hydrogen bonds, which aren’t as strong as other bonds but are sufficient to create a nearly flat sheet of the stuff that can be layered atop each other with the holes storing lithium ions.
The material was discovered by Tianyang Chen and Harish Banda while they were working in the lab of Mircea Dincă, a professor at MIT who has a partnership with Lamborghini to help the hypercar manufacturer electrify its lineup. Lamborghini, which previously used a supercapacitor developed in Dincă’s lab in its Sian model, has licensed the patent on the material.
TAQ’s appeal for Lamborghini is obvious: The material holds more energy than existing battery chemistries, appears to be able to last as long, and can be charged quicker. Less mass is paramount in sports cars, and everyone, not just Lambo owners, would benefit from faster charging.
Batteries made with TAQ could also be cheaper. The MIT researchers estimate that the bill of materials for a TAQ cathode could be a third to half as expensive as NMC. Given that NMC cathodes account for nearly half the materials cost of a lithium-ion battery, that could trim today’s battery costs by 10% to 15%.
The actual savings, though, will depend on a lot more than just which chemicals are required to make a battery. TAQ would almost certainly require changes to the way batteries are made. Battery manufacturers, which have either built or planned hundreds of gigafactories around the world, would be hesitant to upend billions of dollars in capital spending. The battery landscape is littered with chemistries that are brimming with potential but haven’t been able to clear the commercial hurdle.
Geopolitics might change that equation, though.
China dominates nearly every part of today’s cathode supply chain, according to Benchmark Minerals Intelligence. Over three-quarters of finished cathode production happens in the country. It also has a stranglehold on nickel, cobalt and manganese production and refining. Further upstream, cobalt mining is also largely under Chinese control. While the majority of cobalt is mined in the Democratic Republic of Congo, Chinese firms own many mines, and the country has a cozy relationship with the DRC’s state mining company that controls most of the rest. TAQ would allow just about any country with sufficient know-how and expertise to make cathodes for lithium-ion batteries.
Even without a geopolitical thumb on the scale, TAQ might still find a place in the market or eventually dominate. A high-price, high-margin product like a Lamborghini is a great place to start since there’s plenty of room to absorb higher costs that result from new, low-volume technologies. It might be the beachhead the chemistry needs to break into the mainstream. That journey, though, will be long and filled with obstacles. Don’t expect a TAQ-powered car in your driveway anytime soon.