MIT chemists developed a battery cathode based on organic materials, which could reduce the EV industry’s reliance on scarce metals.
MIT News reports Cobalt-Free Batteries Could Power Cars of the Future.
Many electric vehicles are powered by batteries that contain cobalt — a metal that carries high financial, environmental, and social costs.
MIT researchers have now designed a battery material that could offer a more sustainable way to power electric cars. The new lithium-ion battery includes a cathode based on organic materials, instead of cobalt or nickel (another metal often used in lithium-ion batteries).
In a new study, the researchers showed that this material, which could be produced at much lower cost than cobalt-containing batteries, can conduct electricity at similar rates as cobalt batteries. The new battery also has comparable storage capacity and can be charged up faster than cobalt batteries, the researchers report.
“I think this material could have a big impact because it works really well,” says Mircea Dincă, the W.M. Keck Professor of Energy at MIT. “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.”
However, cobalt has significant downsides. A scarce metal, its price can fluctuate dramatically, and much of the world’s cobalt deposits are located in politically unstable countries. Cobalt extraction creates hazardous working conditions and generates toxic waste that contaminates land, air, and water surrounding the mines.
“Cobalt batteries can store a lot of energy, and they have all of 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 says.
About six years ago, Dincă’s lab began working on a project, funded by Lamborghini, to develop an organic battery that could be used to power electric cars. While working on porous materials that were partly organic and partly inorganic, Dincă and his students realized that a fully organic material they had made appeared that it might be a strong conductor.
This material consists of many layers of TAQ (bis-tetraaminobenzoquinone), an organic small molecule that contains three fused hexagonal rings. These layers can extend outward in every direction, forming a structure similar to graphite. Within the molecules are chemical groups called quinones, which are the electron reservoirs, and amines, which help the material to form strong hydrogen bonds.
Those hydrogen bonds make the material highly stable and also very insoluble. That insolubility is important because it prevents the material from dissolving into the battery electrolyte, as some organic battery materials do, thereby extending its lifetime.
“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 says.
Lamborghini has licensed the patent on the technology. Dincă’s lab plans to continue developing alternative battery materials and is exploring possible replacement of lithium with sodium or magnesium, which are cheaper and more abundant than lithium.
Six Minute Charge Time
ACS Publications has a technical PDF on Layered Organic Cathode for High-Energy, Fast-Charging, and Long-Lasting Li-Ion Batteries
Eliminating the use of critical metals in cathode materials can accelerate global adoption of rechargeable lithium-ion batteries. Organic cathode materials, derived entirely from earth-abundant elements, are in principle ideal alternatives but have not yet challenged inorganic cathodes due to poor conductivity, low practical storage capacity, or poor cyclability. Here, we describe a layered organic electrode material whose high electrical conductivity, high storage capacity, and complete insolubility enable reversible intercalation of Li+ions, allowing it to compete at the electrode level, in all relevant metrics, with inorganic-based lithium-ion battery cathodes. Our optimized cathode stores 306 mAhg−1 cathode, delivers an energy density of 765Wh kg−1cathode, higher than most cobalt-based cathodes, and can charge−discharge in as little as 6 min. These results demonstrate the operational competitiveness of sustainable organic electrode materials in practical batteries
Lamborghini licenses MIT’s Cobalt-free organic battery tech for EVs
Energy World reports Lamborghini licenses MIT’s Cobalt-free organic battery tech for EVs.
If this technology works. it will dramatically speed up adoption of EVs, while lowering costs.
Any battery engineers care to comment?
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