Interview with Guillermina Luque (LAES)

Guillermina Luque is in charge of the Sustainable Energy Laboratory at the National University of Córdoba. It is one of the leading groups in Argentina focused on the study of lithium batteries.

In this interview, she explains how a battery is capable of storing something as intangible as electricity and discusses the Argentine scientific community's stance on the environmental challenges posed by this technology.

- What are the differences between lithium batteries and those in current cars?

There are primary and secondary batteries. A primary battery, such as the one in a remote control, can be used only once. Secondary batteries, like lead-acid car batteries and cellphone batteries, are rechargeable. A lithium battery is better than a lead-acid one because it has a higher capacity, meaning it can store more energy in the same mass. That's why there are no electric cars with lead-acid batteries. Lithium batteries also have better cycleability, meaning a longer lifespan or the number of times the battery can be charged and discharged.

- How do batteries store energy?

It’s an electrochemical process. Batteries have two electrodes, one called the anode and the other the cathode, where the electrochemical reactions take place. When the battery discharges energy, an electrochemical reaction occurs, releasing electrons, which is the energy. In lithium-ion batteries, those electrons come from lithium ions as they 'travel' from the anode to the cathode.

When we charge it by plugging it in, we are forcing a reversal of that chemical reaction. We are supplying electrons from the electrical grid to produce the reverse electrochemical process. These are Redox (reduction/oxidation) reactions, which you may have studied in school.

This is the process used in lithium-ion batteries, which evolved from the primary lithium metal batteries to rechargeable lithium-ion ones. Thirty years ago, there were other secondary batteries like lead-acid or nickel-cadmium, but lithium is a very light material, allowing for greater energy density.

- What room is there for further improvement in lithium-ion batteries after 30 years of research?

The issue with today's batteries is the cathode. The technology has reached the maximum energy density that a battery of this type can deliver. The chemistry of these batteries has reached its limit. These cathodes can be made of nickel, manganese, and cobalt (NMC) or iron and phosphate (LFP) in varying proportions. But the lithium-ion remains. The next generation of batteries will be post-lithium-ion. Here, there are considerations for lithium-air or lithium-sulfur batteries. These new technologies will allow electric vehicles to have a range of over 400 kilometers, which is what the best electric cars of today can achieve.

- How long until this new generation of batteries arrives in the industry?

Between 10 and 20 years, but there are also ideas for batteries that don’t use lithium. However, the vehicle market already knows that different types of lithium-ion batteries will be used for the next 20 or 30 years.

- It's always news when an electric car catches fire or explodes. How safe are lithium batteries?

These incidents are rare and happen due to something very specific—a short circuit between the two battery electrodes because there's a problem with the insulator separating them. Also, the elements in the battery are volatile. Let’s think about current cars, which carry liters of fuel in their tanks and also catch fire or explode, yet we use them without fear. Electric vehicles are still in the novelty stage, and, in general, people are afraid of new things. The development of these batteries has years of research aimed not only at improving their capacity but also their safety. Therefore, electric vehicles are as safe or safer than internal combustion vehicles.

- How large is the Argentine scientific ecosystem studying the lithium chain?

There must be at least 300 researchers studying everything from new extraction methods in salt flats to the development of post-lithium-ion batteries. There are also social scientists studying the impacts of this industry on the communities where the resources are located. Argentine science has great capacity, and other countries value this human resource so much that they offer important job opportunities. The problem is that Argentina still can’t fully take advantage of that potential and knowledge. There is a lack of political will and financial support for local science. Argentina never maintains continuity with any policies. A few years ago, lithium research was promoted with a strategic approach, but now changes have been made that, for example, hurt our group in Córdoba, one of the most important in the country.

- What could be the real impact of lithium batteries in the fight against climate change?

We shouldn’t just think about lithium batteries for electric vehicles but in the context of an energy transition. We need batteries to store renewable energy, like wind or solar, which are intermittent. Also, in Argentina’s case, there is no point in having electric vehicles if the power generation source is still fossil fuels. Furthermore, in vast territories like Argentina, the use of batteries is necessary to supply isolated towns.

- When researchers work on these developments, is the goal to help reduce climate change?

In Argentina, lithium is often mentioned more as a resource that can generate foreign exchange and jobs, but we know that lithium batteries are necessary to help reduce greenhouse gases. We also know the conflict surrounding water issues, and many researchers are studying this problem and trying to find solutions. Extraction methods will improve to become more environmentally friendly. However, we shouldn’t forget that to make lithium batteries, not only lithium is needed, but other metals as well, which also require extraction methods that aren’t environmentally friendly.

- There’s also the ongoing debate about whether lithium should be considered a strategic mineral, as in other countries. Or that companies should pay more royalties to help develop the communities and even support science related to lithium.

- Why should Argentina have scientists who understand the science and technology behind the production of lithium batteries?

First, because the country should explore the possibility of producing batteries. It will be difficult to compete with China and other powers, but we shouldn’t discard it, especially since we already have qualified resources. Also, having the know-how is beneficial for knowing if the batteries we are importing are of good quality and for being able to monitor all devices that use batteries.