3 Sep 22

Are aluminium-air batteries the best solution for EVs?

We shouldn't get too excited, too quickly, upon hearing about a new electric vehicle (EV) battery technology but we can't help it in this case. While several new types of EV battery are being developed, one stands out as potentially the optimum solution for range, energy and recycling concerns. 

Aluminium-air (AI) batteries are another highly futuristic EV battery the auto industry expects to see in commercial applications around the 2030s, along with other innovations. AI-air batteries are not directly tied to the grand changes expected in the rare mineral mining industry compared to its rivals. 

Despite the efforts to switch to non-lithium batteries for the future, including sodium-ion and silicon anode batteries, lithium will likely continue to dominate the EV battery market through increasing demand and also new battery types such as lithium-sulphur and lithium-iron phosphate (LiFePO4) batteries.  

According to McKinsey, lithium demand will surge between the 2021 demand level of around 500,000 metric tons to reach 3-4 million metric tons in 2030. Additionally, the surge in EV sales since 2019 has strengthened lithium investments, pushing up prices. Virta figures show that EV sales jumped 43% in 2020 despite the pandemic compared to 2019, and in 2021 EV sales doubled from 2020, reaching 6.75 million globally. The demand was so strong that "the number of EVs sold in a week in 2021 was higher than the number sold in the whole of 2012," Virta notes.  

2022 will be no different. EV sales are to hit 10.6 million by the end of the year, jumping 57% over 2021, according to Vehicle Freak. Eventually, lithium prices also surged. McKinsey notes that the price for lithium carbonate reached $75,000 per metric ton by the beginning of March 2022, and lithium hydroxide reached $65,000 per ton. 

The picture above may depict an intense development in the EV industry, boosting investments in technology. Nevertheless, skyrocketing energy prices and the burden they will set on EV owners is not a good sign. According to Britain's energy regulator Ofgem, the energy price cap will rise around 80% from 1 October 2022. 

What is the optimum solution? 

If lithium is too expensive and also causes environmental, labour and recycling concerns, why not just remove it from the equation? 

This is what Métalectrique has been working on for several years, as they describe their technology as "halfway between a battery and a fuel cell." Their equation is a simple transformation of fossil-fueled vehicles. Instead of petrol or diesel, an aluminium-air battery mixes aluminium and O2 to produce not combustion but a chemical reaction. In the end, not CO2 but aluminium hydroxide and electricity comes out. 

Métalectrique describes their technology as an "electric engine", not both but an electric equivalent of an engine, according to EU-China Energy. And what are the advantages of an AI-air electric engine when it becomes real? 

  • AI-air technology will offer ranges up to 1,600 km. 
  • The energy density of the battery is 1,350 kWh/kg, equal to around nine times the energy of lithium-ion batteries.
  • Métalectrique is developing a battery swapping system, which will enable changing batteries in 90 seconds. 
  • The system is based on modules less than 5kg, requiring only warehousing and logistics as battery swapping infrastructure. 
  • Métalectrique says the energy cost is between 29 and 35 euros per kWh for OEMs and $0.15 for the driver, according to the company's tests. 

The rise of xEVs 

One critical characteristic of AI-air technology is it emerges as an extension for xEVs (3D printed EVs). xEVs are a rising trend in Europe, mainly imported from China due to their low-cost and easy operability. 

According to Bloomberg, Chinese EV makers shipped $1.2 billion worth of electric passenger cars, representing a 122% increase from the previous year. Some of these exports include xEVs, which are around €8,000 and €13,000. APAC expert Baran Gumusel says this is possible thanks to the Chinese government's incentives to local OEMs. For each exported EV, the government provides €3,000 to OEMs, which makes this trade profitable. 

As the xEV number rises in Europe and other parts of the world, AI-air technology will likely find a growing space. The AI-Air adapter can turn an EV into a lithium-aluminium-air hybrid, Métalectrique CEO Trevor Jackson tells EU-China Energy. The extender also gives an extra 300 miles (480 km) to an EV with a dying battery. Eventually, AI-air technology could be used to extend the life cycle of lithium-ion batteries and reduce the pressure on the recycling industry. 

Jackson also notes the already existing aluminium recycling industry would have no problem handling the AI-air electric engines. 

When is it coming out? 

Like all other technological developments in the EV industry, the R&D process of AI-air technology will take some time. Métalectrique hopes to align with the International Energy Agency's (IEA) Net Zero roadmap and introduce the electric engine in 20 years. Thus, it would be possible to support the 2050 zero-emission goals. 

Image: Shutterstock

Authored by: Mufit Yilmaz Gokmen