We all know that lithium has risen to prominence as the ultimate rock star of modern-day energy storage, obscuring its close relatives.
Lithium, on the other hand, is far from an unlimited resource on our planet. Argentina, Chile, Australia, and China are the only four nations in the world having significant reserves.
If we don’t get our recycling and repurposing systems in order in the future years, the world may run out of resources. A typical electric vehicle’s battery pack has roughly 10 kg of lithium. According to PV Magazine, if EV sales continue to climb at their current rate, there will be 3 billion of them on the road by 2040, using nearly all of the current 26 million tonnes of lithium.
It’s also tough to extract, needing a lot of carbon-intensive energy and having a lot of negative environmental consequences. Furthermore, most lithium-ion batteries require additional rare materials such as cobalt, which is mostly derived from the Democratic Republic of Congo, which is known for its environmental and human rights difficulties.
Lithium’s less glamorous twin, sodium, on the other hand, is widely available. The earth’s crust has almost 1,000 times more sodium than lithium. It’s a component of sodium chloride, which is, of course, salt.
It’s usually extracted from soda ash, but being the sixth most prevalent element on the world, it’s rather simple to come by, especially when compared to lithium.
Why hasn’t the sodium-ion battery, which is safer, cheaper, and cleaner than lithium-ion, been the darling of electrochemical engineers worldwide, and why aren’t our modern lifestyles powered by sodium-ion batteries instead of lithium-ion?
That is an excellent question. CATL of China, the world’s largest battery manufacturer, appears to agree with you, since they’ve just unveiled a sodium-ion battery that outperforms existing lithium-ion technology in terms of energy density and endurance, and might truly alter the future of energy storage.
So, why didn’t CATL and the rest of the battery companies just utilize salt from the start?
It wasn’t exactly as simple as our scientific colleagues would have thought.
The two battery types have very similar fundamentals.
One negative electrode and one positive charge collector lie on either side of an electrolytic solution, with a separator membrane in the center blocking the passage of electrons inside the battery.
The lithium or sodium atoms release electrons when the system charges up, which flow out of the cathode and along the electrical circuit to the anode on the other side, where they are physically caught inside the anode’s structure. Meanwhile, the lithium or sodium ions traverse the electrolyte on their way to the same place.
When the system is linked to a device, the stored electrons travel out of the battery, creating an electrical current that powers the device before returning to the cathode.
Because sodium ions are physically bigger than lithium ions, they can’t flow easily between layers in a graphite anode like lithium ions can. As a result, the insertion and extraction of sodium ions into and out of the electrodes places greater demands on whichever material was utilized.
CATL has always been at the forefront of research and development as the world’s largest battery manufacturer. With more than 5,000 people in a dedicated R&D team and state-of-the-art computer simulation technology, they’re constantly searching for more sustainable ways of producing these essential products, mindful of the finite nature of the resources available.
They’re already producing lithium-iron-phosphate batteries for all Tesla cars sold in China, for example. These batteries have a lesser energy density than traditional lithium-ion batteries, however they don’t include cobalt.
Tesla has declared that all of its normal production vehicles in the United States would be equipped with lithium-iron-phosphate batteries, so it’s not hard to picture CATL taking moves toward phasing out lithium-based batteries entirely.
CATL introduced the first version of their sodium-ion battery technology in July 2021, with an energy density of 160 Wh/kg and a charge time of under 15 minutes from zero to 80 percent. The materials utilized for the electrodes were the key difference with this newer technique. Prussian White is the substance used for the cathode.
Bods is a totally reduced and sodiated version of Prussian Blue with a high working capacity, high theoretical capacity, and low toxicity that eliminates the requirement for a reactive sodium-loaded anode in cell construction, according to scientists.
To summarize, Prussian White is a low-cost, easy-to-manufacture, non-toxic material with good discharge rates and the potential to maintain a capacity of up to 95% after 10,000 cycles, making it an appealing alternative for a battery cathode.
On the anode side, which is typically made of graphite in lithium-ion batteries, CATL has developed a hard carbon material with a unique porous structure that allows for abundant storage and rapid movement of the larger sodium ions, giving it overall performance and cycle life comparable to graphite.
Because sodium ions do not tend to form an alloy with aluminum, CATL has been able to employ aluminum foil instead of copper as the current collector on the anode side. Not only does this reduce the cost of each battery by around 80%, but it also makes them 10% lighter.
Furthermore, because of the qualities of sodium salt, a less concentrated electrolyte solution may be used, saving even more money.
CATL claims that they can make their new sodium batteries with the same technology and procedures that they use to make lithium-ion batteries, avoiding the need for a costly new set-up. As a cherry on top of the happy little CATL cake, it turns out that sodium-ion batteries have far superior thermal stability than lithium-ion batteries, resulting in increased safety ratings.
The business registered for a patent on a second-generation sodium-ion battery in January 2022, claiming that it will exceed 200 Wh/kg, outperforming lithium-iron-phosphate technology and approaching the performance levels of ordinary nickel-based lithium cobalt batteries.
Full production is expected to begin in 2023, with CATL aiming to supply not just Tesla and other cars, but also low-cost stationary energy storage facilities for power grids throughout the world, easing the way for fast renewable energy adoption.
It’s vital not to get carried away with slick marketing presentations, as with all these seemingly revolutionary new announcements in the field of battery storage systems, and instead focus purely on the product’s real-world performance and economic viability.
Various industry entrants have made a lot of big promises in the past, all claiming to be the next market disruptor. However, only a small percentage of those ideas have come to fulfillment. CATL, on the other hand, is a serious organization that follows through on its promises. Within the next several years, we may see electric cars driven by sodium-ion batteries.
Post time: Jun-20-2022