Designing a Better Battery – Out with Cobalt and In with…TAQ?

Researchers at the Massachusetts Institute of Technology (MIT) have recently developed a new type of battery technology that forgoes the need for precious metals.  In their place? An organic cathode known as bis-tetraaminobenzoquinone or ‘TAQ'.

The Importance Of Batteries

With the rise of EVs (Electric Vehicles) – largely thanks to American Tesla and Chinese BYD and CATL – battery technology has become more important than ever as they are relevant not only for electronics, but also for mobility. And soon for the electric grid as well, in order to balance out the intermittency of renewable energies like wind and solar.

Global EVs sales – Source: IEA

To this day, the dominant chemistry for batteries is lithium-ion technology. This is because these batteries are some of the energy dense available when measured in kW/kg. This metric is by far the most important in mobility applications, as every extra kilo of battery means a need for more battery and/or less range.

So, since EVs have proven to be the likely key future technology for automobiles (and maybe trucks and even planes), considerable effort has been made to improve battery technology.

Giving Up Lithium-Ion?

While highly dense, traditional lithium-ion technology is not without flaws. There is a list of problems to be solved:

• Density is still rather low compared to liquid fuels like gasoline and diesel, causing range anxiety.
• Charging can be somewhat slow, which is a problem for many drivers and commercial applications.
• Batteries are expensive, largely due to the need for expensive minerals.
  • This caused EVs to be initially more of a luxury good than a normal consumer good.
  • The mining of these minerals is rarely environment friendly and often comes together with appalling work conditions and exploitation of poor workers or children in mines, especially in the case of cobalt in Congo.

As a result, plenty of alternative chemistries have been considered. This includes and is not restricted to,

• LFP (Lithium-Ferrum/iron-Phosphate)
• sodium-ion
• solid-state batteries
• lithium-sulfur
• graphene
• glass batteries

The oxydation of aluminum has even been discussed as an alternative to batteries altogether. However, all of these alternatives have their limitations. This can include a shorter lifespan, manufacturing difficulty, etc.

(We discussed in detail the advantages and limitations of each of these technologies in our article “The Future of Mobility – Battery Tech”).

The most promising, like solid-state batteries, are still at an experimental stage, and the ones ready for commercialization, like LFP and sodium-ion, suffer from lower energy density than lithium-ion.

There is probably a market for these lower-density batteries, as they are also much cheaper to produce. The Chinese company CATL (300750.SZ), which produces more than half of the planet's batteries, is among the leaders in this field. We discussed the leading battery manufacturers in our article “Top 10 Battery Stocks To Invest In”.

Still, ultimately, the ideal EV would have a cheap AND powerful battery. This combination will be likely required to fully replace the combustion engine, especially for commercial applications.

The Lithium-Ion Cathode Problem

Most of the limitations of lithium-ion come from the chemical and physical properties of the cathode part of the battery. It is the cathode that typically requires cobalt, and even in cobalt-free potential alternatives, usually relies heavily on other costly metals like nickel and magnesium.

(The metals required for the transition to EVs and renewables were discussed further in our article “Top 10 Battery Metals & Renewable Energy Mining Stocks”)

These metals are required to be mined, cause pollution, and work conditions are often terrible. They are also toxic, making recycling batteries a more complicated task.

Source: Visual Capitalist

Researchers have been looking at carbon-based alternatives, or the so-called organic cathodes. For now, this has been rather unsuccessful, as organic cathodes have either been too low in energy density or not durable enough to use in the context of frequent charge-discharge cycles of EVs.

This might have changed, thanks to the aforementioned discovery by MIT researchers.

A New Type Of Organic Cathode

Pr. Mircea Dincă, working at the W.M. Keck Professor of Energy at MIT, has recently explored new organic compounds previously untested for cathode applications. Instead of the previously explored organosulfur and carbonyl compounds, he looked at a compound called TAQ (bis-tetraaminobenzoquinone). His team had previously demonstrated the potential of this chemical as a supercapacitor material.

TAQ has great potential for use in batteries, as it forms “layered solid-state structures than can potentially compete with traditional cobalt-based cathode performance.”

In itself, this would not have been enough. The MIT researchers also found how to improve the adherence of TAQ to the cathode’s stainless-steel current collector, improving the stability of the new proof-of-concept cathode prototype.

By adding cellulose- and rubber-containing materials to the TAQ, they safely achieved more than 2,000 charge-discharge cycles. The energy density was also higher than with cobalt-based cathodes, and the charging took less than 6 minutes.

What’s Next?

This is, for now, a laboratory prototype, and further work will be required to scale it up to the full EV battery pack size—and even further effort to see how to make a scaled-up manufacturing process for this new battery chemistry.

Still, this is among the first time that an organic cathode has out-competed cobalt-based lithium-ion designs on every important metric: energy density, cost of materials, and charging speed.

This shows that lithium-ion chemistry could stay the mainstream battery chemistry, as long as it can solve its reliance on metals that cause ethical and environmental issues.

Another thing the research by Pr Dincă proves is that organic cathodes have great potential, with potentially thousands of other organic compounds yet untested for this application. So even if TAQ ends up insufficient to displace cobalt and nickel, other chemicals similar to TAQ might achieve it.

Lithium-ion designs also benefit from a massive preexisting supply chain and manufacturing base. And it would be a lot easier just to change the cathode than rebuild battery factories from the ground up to accommodate new chemistries. So, improving lithium-ion might make a lot of sense from a business point of view.

It is also worth noting that organic cathodes have been discussed for other types of batteries as well, for example, for aluminum-ion, sodium/potassium-ion, zinc, or calcium-based dual-ion batteries. So, it is possible that the discovery of TAQ's properties can be applied to other battery types than lithium-ion.

In any case, organic components in batteries will make them easier to recycle, an issue (an investing opportunity) we explored in depth in our article “Addressing the Li-ion Dilemma: Disposing of Defunct Battery Cells in an Increasingly Electrified World”.

Organic Cathode Companies

Volkswagen AG

The research of Pr. Mircea Dincă was funded by Automobili Lamborghini S.p.A., a subsidiary of Audi, owned by the Volkswagen Group. A patent application for the organic cathode technology has already been filed.

The German automaker is the second-largest car producer in the world, behind only Toyota. The company was, for a time, lagging in EV technology but has worked hard to catch up since, notably with the ID car series and multiple hybrid models as well.

Source: Volkswagen

By 2033, the Volkswagen Group is planning to produce only EVs in Europe.

The collaboration with the MIT researchers is just one among many, with other partnerships about EVs including:

• A partnership with Renault for a 20,000-euro EV.
• A $700M investment in Chinese Xpeng to boost EV sales in China.
• A partnership with Chinese SAIC Motor to supply EV platforms to Volkswagen.
• A partnership with Jetta Motor for acquiring EV technology.
• A $492M partnership with Magna to revitalize the iconic Scout SUVs as an EV

With its ambitious plans regarding EVs and access to advanced EV technology from leading Chinese companies, Volkswagen is in a good position to look at MIT's organic cathode patented technology and work on deploying it at scale in its future EVs.

Other Organic Battery Companies

While they are not developing new cathodes, two startups are working on using organic compounds to improve the anode performances, Store Dot and EnergyX.