Sodium Batteries May Power New Electric Cars

Half a century ago, the battery of the future was built out of sodium. The reason has to do with why the seas are salty. Sodium is a light element that ionizes easily, giving up one of its electrons. In a battery, those ions shuttle back and forth between two oppositely charged plates, generating a current. This looked like a promising way to power a house or a car. But then another element crashed the party: lithium, sodium’s upstairs neighbor on the periodic table. In 1991, Sony commercialized the first rechargeable lithium-ion battery, which was small and portable enough to power its handheld video cameras. Lithium was lighter and easier to work with than sodium, and so a battery industry grew up around it. Companies and research labs raced to pack more energy into less space. Sodium faded into the background.

So it was surprising this summer when China’s CATL, one of the world’s largest battery makers, announced sodium would play a role in the electrified future. CATL, like its competitors, is a lithium company through and through. But starting in 2023, it will begin placing sodium cells alongside lithium ones inside the battery packs that power electric cars. Why? Well, for one thing, a CATL executive pointed out that sodium is cheaper than lithium, and performs better in cold weather. But it was also hedging against an issue that was difficult to imagine in 1991. By the end of this decade, the world will be running short on the raw materials for batteries—not just lithium, but also metals like nickel and cobalt. Now that electrification is actually happening on a big scale, it’s time to think about diversifying. A CATL spokesperson said it started thinking about sodium 10 years ago.

CATL’s announcement “really injected new energy into the people who work on sodium,” says Shirley Meng, a battery scientist at the University of California, San Diego who works extensively with both elements. As a young professor, Meng started working with sodium in part because she was looking for a suitably weird niche to stand out in—but also because she believed it had potential. “The biggest barrier to success for sodium was that lithium was so successful,” she says.

Lithium is not exceptionally rare. But deposits are concentrated in places that are hard to mine. So companies like CATL compete to secure a slice of the supply from a limited number of mines, mostly located in Australia and the Andes. Meanwhile, reserves in North America are tied up in environmental disputes, raising concerns in the US about the security of the supply chains. Competition is even fiercer for nickel—which Elon Musk has called the “biggest concern” for the future of EV batteries, due to price and supply constraints—and for cobalt, 70 percent of which is dug up in the Democratic Republic of the Congo.

As more mines open, there will probably be enough lithium to power all the world’s vehicles, Meng says. But that doesn’t account for all of the things poised for electrification that aren’t cars: chiefly, the batteries that will manage the load within microgrids and keep our lights on at night when the rooftop solar panels are in the dark. Those are the kinds of applications Meng had in mind when she got into sodium research. “I was thinking everybody would have a refrigerator for electrons in your home in the same way you have a refrigerator for food,” she says. “I think that really is the vision for grid storage.


Could Deep Sea Mining Fuel The Electric Vehicle Boom?

The world is hungry for resources to power the green transition. As we increasingly look to solar, wind, geothermal and move towards decarbonization, consumption of minerals such as cobalt, lithium and copper, which underpin them, is set to grow markedly. One study by the World Bank estimates that to meet this demand, cobalt production will need to grow by 450% from 2018 to 2050, in pursuit of keeping global average temperature rises below 2°C. The mining of any material can give rise to complex environmental and social impacts. Cobalt, however, has attracted particular attention in recent years over concerns of unsafe working conditions and labour rights abuses associated with its production.

New battery technologies are under development with reduced or zero cobalt content, but it is not yet determined how fast and by how much these technologies and circular economy innovations can decrease overall cobalt demand. Deep-sea mining has the potential to supply cobalt and other metals free from association with such social  strife, and can reduce the raw material cost and carbon footprint of much-needed green technologies.

On the other hand, concerned scientists have highlighted our limited knowledge of the deep-sea and its ecosystems. The potential impact of mining on deep-sea biodiversitydeep-sea habitats and fisheries are still being studied, and some experts have questioned the idea that environmental impacts of mining in the deep-sea can be mitigated in the same way as those on land.

Electric Cars Soon Less Expensive Than Petrol Vehicles

An international research team has pioneered and about to patent a new filtration technique that could one day slash lithium extraction times and change the way the future is powered. The world-first study, published today in the journal Nature Materials, presents findings that demonstrate the way in which Metal-Organic Framework (MOF) channels can mimic the filtering function, or ‘ion selectivity’, of biological ion channels embedded within a cell membrane.

Inspired by the precise filtering capabilities of a living cell, the research team has developed a synthetic MOF-based ion channel membrane that is precisely tuned, in both size and chemistry, to filter lithium ions in an ultra-fast, one-directional and highly selective manner. This discovery, developed by researchers at Monash University, CSIRO, the University of Melbourne and the University of Texas at Austin, opens up the possibility to create a revolutionary filtering technology that could substantially change the way in which lithium-from-brine extraction is undertaken. This technology is the subject of a worldwide patent application filed in 2019. Energy Exploration Technologies, Inc. (EnergyX) has since executed a worldwide exclusive licence to commercialise the technology.

Based on this new research, we could one day have the capability to produce simple filters that will take hours to extract lithium from brine, rather than several months to years,” said Professor Huanting Wang, co-lead research author and Professor of Chemical Engineering at Monash University. “Preliminary studies have shown that this technology has a lithium recovery rate of approximately 90 percent – a substantial improvement on 30 percent recovery rate achieved through the current solar evaporation process.”

Professor Benny Freeman from the McKetta Department of Chemical Engineering at The University of Texas at Austin, commented: “Thanks to the international, interdisciplinary and collaborative team involved in this research, we are discovering new routes to very selective separation membranes. “We are both enthusiastic and hopeful that the strategy outlined in this paper will provide a clear roadmap for resource recovery and low energy water purification of many different molecular species.”

Associate Professor (Jefferson) Zhe Liu from The University of Melbourne explained: “The working mechanism of the new MOF-based filtration membrane is particularly interesting, and is a delicate competition between ion partial dehydration and ion affinitive interaction with the functional groups distributed along the MOF nanochannels. “There is significant potential of designing our MOF-based membrane systems for different types of filtration applications, including for use in lithium-from-brine extraction.”