How A ‘Breakthrough Technology’ From A Swedish Start-Up And An Indian Company May Change The EV Battery Game

Over the last month, two announcements have been made about a new type of battery, one that could majorly shake things up if all the promises turn out to be true.

The new kid on the block is sodium-ion batteries, which swap sodium for the lithium that powers most electric vehicles (EVs) and devices like mobile phones and laptops today.

In November 2023, Northvolt, a Swedish start-up, revealed the development of a sodium-ion battery that has no lithium, cobalt or nickel — critical metals that manufacturers have scrambled to obtain, leading to volatility in prices.

Back home, KPIT Technologies, a Pune-based company, unveiled its Sodium (Na)-ion battery technology, proudly asserting itself as the first Indian company and the fourth globally to possess a proven technology solution for sodium-ion battery storage.

Lithium Dominance

The chances are, you are reading this article on a laptop or smartphone, which will have a lithium-ion battery (LIB) inside them.

In the world of electrochemical batteries, lithium-ion is the king — due to its light weight and longer life cycle. However, the main reason for their high adoption in EVs is their high energy density. High energy density allows lithium-ion batteries to store more energy in less weight per unit volume, thereby allowing vehicles to move over long distances.

But just as batteries have a positive end and a negative end, LIBs have negative points set against their positive ones.

For one thing, while traditional LIBs are some of the most power-dense portable energy sources, it is approaching its physico-chemical limit, resulting in a cap on their energy density and recharge cycles.

However, a particularly concerning issue with current LIBs revolves around elements employed in their construction, with these rechargeable batteries using cobalt, nickel, and manganese in their electrodes.

According to an estimate by International Monetary Fund (IMF), a typical electric vehicle battery pack may need around 8 kilograms (18 pounds) of lithium, 35 kilograms of nickel, 20 kilograms of manganese and 14 kilograms of cobalt, while charging stations require substantial amounts of copper.

While the global electric vehicle market is on the cusp of exponential growth in the wake of a big push to transport decarbonisation, auto makers may encounter bumpy roads ahead, as they face challenges to secure supplies of raw materials used for battery production, according to a report by independent research organisation A T Kearney Energy Transition Institute.

Branching Out

Sodium, positioned just below lithium on the periodic table, shares both chemical and structural similarities with the latter. However, it is cheaper and far more abundant and cells made with the material can reach similar voltages to lithium-ion cells (meaning the chemical reactions that power the battery will be nearly as powerful).

Yet, the energy output per unit size of sodium cells has historically fallen behind lithium batteries, rendering them currently unsuitable for most electric vehicles, especially where space is a critical factor. Nevertheless, this is beginning to change, as sodium-based batteries have recently been cramming more energy into a smaller package.

Sample this, the sodium-ion battery developed by Northvolt has been validated at 160 watt-hours per kilogram, an energy density close to that of the type of lithium batteries typically used in energy storage. Lithium batteries used in electric cars have an energy density of up to about 250-300Wh per kg while those typically deployed in energy storage have about 180Wh per kg.

Additionally, SIBs provide enhanced safety in comparison to LIBs. Sodium exhibits lower chemical reactivity than lithium, thereby decreasing the chances of thermal runaway (which is, overheating) or fire hazards commonly associated with lithium-based batteries.

Supply Conundrum

Researchers are actively exploring methods to minimise the reliance on the costliest and scarcest components in battery technology. While certain alternatives already exist to decrease the dependence on elements such as cobalt and nickel, challenging lithium's dominance has proven more elusive.

Nevertheless, a potential shift is on the horizon, thanks to the recent unveiling of two innovative technologies last month. These advancements hold promise in alleviating concerns surrounding the battery supply chain.

The geological abundance of sodium — the earth’s crust contains about 1,300 times more of sodium than lithium, itself hardly a rare commodity — makes it cheaper to extract, thereby, enabling potentially lower production costs, making SIBs an attractive option for EVs.

To start with, Northvolt — backed by Volkswagen, BlackRock and Goldman Sachs — has claimed that its cell is produced with minerals such as iron and sodium that are abundant on global markets. Featuring a salt-based Prussian White cathode and a bio-based hard carbon anode, the technology entirely avoids use of critical metals including lithium, nickel, cobalt and graphite.

Similarly, KPIT's indigenous battery technology’s cornerstone is utilising Earth-abundant raw materials, thereby making electric mobility more affordable.

To be sure, Contemporary Amperex Technology Company Limited (CATL), the world’s largest battery maker, in 2021 launched the first-generation sodium-ion battery with a energy density of 160Wh per kg. However, all such previous attempts used oxides containing metals such as nickel, cobalt or manganese in their sodium-ion batteries. The use of the metals make them more expensive and less safe as they could catch fire at lower temperatures.

“We are not that dependent on a number of these strategic supply chains that China has created in a very efficient way,” said Peter Carlsson, Northvolt’s chief executive and co-founder.

The Price-Demand Seesaw

Experts argue that although market conditions have created opportunities for lithium alternatives, they have the potential to close the door just as swiftly.

The future prospects of sodium-ion batteries are “directly tied to the cost of lithium", according to Jay Whitacre, a battery researcher at Carnegie Mellon University and founder of Aquion, a sodium-ion battery company.

Echoing the sentiment, Iola Hughes, research manager at battery consultancy Rho Motion says that while it is "quite key to be the first ex-China player to have a sodium-ion product validated for energy storage", the "potential success of sodium-ion batteries would depend on the price of lithium batteries, which have fallen in recent months, and on how quickly manufacturers such as Northvolt could scale the new technology".

In the scenario where sodium-ion batteries are gaining traction in the market due to cost and material accessibility, a decline in lithium prices could pose significant challenges for them.

"It’s hard enough to make new batteries and build them at large scale, it’s even harder to chase a moving target of ever-improving lithium-ion batteries that are getting cheaper," says Whitacre.

Encouragingly, both newcomers are actively working towards the global commercialisation of this technology. Northvolt, in particular, aims to deliver initial samples to customers next year and achieve full-scale production by the end of the decade.

 “Our Sodium-ion battery technology, completely reliant on Earth’s abundant raw materials, is another testament to KPIT’s commitment towards the sustainable mobility ecosystem. We look forward to partnering with manufacturing companies to commercialise this technology globally”, said Ravi Pandit, co-founder and chairman of KPIT Technologies.

To sum it up, while sodium technology is unlikely to dethrone lithium, it may well discover its rightful niche.

“The combination of thermal capability, cost, and the sustainability aspect makes us very bullish about the possibility of the technology. This is a really large opportunity for areas like the Middle East, Africa and India,” Northvolt’s chief executive said.