Lamborghini funds a cobalt-free battery

Researchers at MIT have demonstrated a lithium-ion battery cathode made with organic materials, offering a more sustainable way to power electric vehicles, and Lamborghini is all-in.

"I think this material could have a big impact because it works really well," said Mircea Dincă, W.M. Keck Professor of Energy at MIT and senior author of a paper on the findings published in the journal ACS Central Science. "It is already competitive with incumbent technologies, and it can save a lot of the cost and pain and environmental issues related to mining the metals that currently go into batteries."

The new battery includes a cathode based on organic materials, replacing cobalt and nickel, which could be produced at a much lower cost than batteries containing cobalt, has a comparable storage capacity, and would conduct electricity at similar rates, with faster charging.

Cobalt alternatives

Most mainstream lithium-ion batteries produced today contain cobalt cathodes, which offer high stability and energy density. But the price is high – not only due to scarcity of the metal, but socioeconomically due to political instability and hazardous working conditions.

Much of the cobalt produced is poorly regulated and often the processes generate heavy emissions and environmental issues.

"Cobalt batteries can store a lot of energy, and they have all of the features that people care about in terms of performance, but they have the issue of not being widely available, and the cost fluctuates broadly with commodity prices. And, as you transition to a much higher proportion of electrified vehicles in the consumer market, it's certainly going to get more expensive," Dincă said.

Research has steadily gone into developing alternative battery materials, such as lithium-iron-phosphate, which some automotive manufacturers are beginning to use despite usually possessing only about half the energy density of cobalt and nickel batteries.

Until now, organic materials have not been able to match the conductivity, storage capacity, and lifetime of cobalt-containing batteries, which typically require polymer binders to help them maintain a conductive network. These binders, which make up at least 50% of the overall material, bring down the battery's capacity.

Lamborghini goes organic

Roughly six years ago, Lamborghini began funding a battery development project with Dincă's lab to create an organic EV battery, later discovering that a fully organic material they had made appeared to be an unusually strong conductor.

This material consists of a layered molecule that contains three fused hexagonal rings in a structure similar to graphite, called bis-tetraamino-benzoquinone, or TAQ.

TAQ molecules contain chemical groups called quinones, which serve as electron reservoirs, and amines, which help form strong hydrogen bonds that make the material insoluble and highly stable. Insolubility specifically prevents eventual dissolution into the battery electrolyte, a key flaw in other organic battery materials.

"One of the main methods of degradation for organic materials is that they simply dissolve into the battery electrolyte and cross over to the other side of the battery, essentially creating a short circuit. If you make the material completely insoluble, that process doesn't happen, so we can go to over 2,000 charge cycles with minimal degradation," Dincă said.

The key materials required in manufacturing this type of cathode are quinone and amine precursors, which are commercially available as commodity chemicals. The estimated cost of materials in assembling these organic batteries could be as low as one-half to one-third the cost of batteries using cobalt.

Performance tests have proven MIT's TAQ cathode has comparable conductivity and storage capacity to traditional cobalt-containing lithium batteries. In addition, batteries with TAQ cathodes have a faster charging rate than existing batteries, an improvement of notable appeal to the EV market.

To stabilize and increase the new material's adherence to copper or aluminum collectors, the research team added cellulose and rubber filler materials. These fillers make up less than one-tenth of the overall cathode composite, preventing cracking while avoiding significant reduction of the battery's overall storage capacity.

Lamborghini has licensed the patent on the technology. Meanwhile, Dincă's lab plans to continue developing alternative battery materials and is exploring possible cheaper and more abundant replacements for lithium, like sodium and magnesium.