While Lithium-ion batteries have become ubiquitous with modern technology, a competitor is on the rise. Researchers working on Sodium-ion batteries (SIBs) hope to reduce the reliance on the former due to the impact of mineral mining and rising costs.
Sodium-ion batteries present an opportunity to further reduce environmental impact and accelerate EV adoption.
Some experts believe that battery chemistry system will not see any further major breakthroughs, but industry leaders disagree. Continue reading to get a further look into the future viability of SIBs.
Sodium-Ion Batteries Overview
The basics of Sodium-ion batteries were discovered at the same time as Lithium-ion batteries, but the pace of innovation pulled all research and commercial interests towards Li-ion batteries.
The first true Sodium-ion battery was created in 2009, by a company called Aquion Energy. Just like with a Li-ion battery, sodium travels back and forth between cathode and anode in a Sodium-ion battery cell.
Scientists are working to develop a SIB that can compete with Lithium-ion batteries. The high degree of research interest is driven by the abundance and relative cost-savings of Sodium (Na) over Lithium (Li).
While the major hurdle preventing commercialization and industrialization of Sodium-ion batteries is related to the larger volume and higher structure requirements of SIBs.
Sodium-ion batteries share similarities with the chemistry of LIB systems, but are different enough that research has been ongoing to identify the best anode and cathode materials to maximize energy storage capacity.
Sodium-Ion Batteries vs Lithium-Ion Batteries
Lithium-ion batteries (LIBs) have been key to the rise of electronics and handheld devices after they were first commercialized in 1991.
Inventors of LIBs, Goodenough, Wittingham, and Yoshino, received the Nobel Prize in Chemistry for their contribution.
Lithium-ion batteries continue to get cheaper and safer. Laptops, cellphones, tablets, tools, headsets, electric toothbrushes, and electric vehicles are just a few of the common devices powered with rechargeable LIBs.
But Lithium-ion batteries are ‘dirty’ and relatively expensive. The best raw materials for Li-ion battery chemistry include minerals that are scarce, expensive, and lead to dangerous, polluting mining environments.
For EVs to further expand and replace gas-powered vehicles, they need to be priced more competitively.
Sodium-Ion Battery Pros
The reduced cost of sodium over lithium is the major driver behind funding development of a competitive Sodium-ion battery system. As lithium grows increasingly expensive, the lower costs associated with sodium are highly beneficial.
Sodium-ion technology does not require scare resources, while lithium salts are rare, but table salt is plentiful. Lithium-ion batteries require cobalt mining, which has major environmental and ethical implications.
Powerful anodes for Sodium-ion batteries can be produced from lignite, wood and other biomass. Cobalt and similar rare minerals are not required.
A successful Na-ion battery will have a long charge hold time, risk of battery damage, degradation, or automatic discharge. The reaction will not be corrosive and a long cycle life is expected.
According to CATL their Sodium-ion battery charges significantly faster than Lithium-ion batteries and offer more thermal stability.
Na-ion batteries can reach 80% charge within 15 minutes. The low temperature performance can also improve charging capability and speeds in winter months and colder climates.
Sodium-Ion Battery Cons
Unfortunately, the risk of fire or explosion present with Lithium-ion batteries remains with Sodium-ion batteries, because of the continued reliance on highly flammable organic solvents.
Na-ion batteries will be heavier than their counterparts because sodium is 3x heavier than lithium. This may have noticeable weight effects on mobile devices like mobile phones, laptops, and tablets.
Sodium-ion batteries will struggle to be competitive against lithium options until a superior anode is developed. Graphite anodes don’t absorb enough sodium absorption and therefore have a lower voltage. Around 0.3 volts lower. This means 10% less energy density compared to Lithium-ion batteries.
Price of Sodium-Ion Batteries
Consumers can expect reduced costs if technologies transition to Sodium-ion batteries. Quotes are currently 20-40% cheaper for Na-ion battery cells than their lithium counterparts.
This will drive electric vehicle prices into a very affordable range and contribute to further electrification of transportation. Consumers will see prices for mobile devices drop as well.
Current State of Development
Currently Sodium-ion batteries lags behind Li-ion batteries by roughly 20 years, but the technology is rapidly improving.
In July 2021 CATL unveiled it’s first Sodium-ion battery that can be integrated with Lithium-ion battery cells into a single pack. This pack is intended for use in electric vehicles.
Ultimately, development of viable Na-ion battery systems hinges on the improvement of battery chemistry. A suitable anode that can support the larger sodium molecules is needed. Graphite does not meet this requirement.
German-Russian researchers are working to resolve the issue with current Graphite anodes. Their research suggests that wafer-thin layers of graphene may improve the transfer of sodium ions. Oxide and polyanion cathodes are the best performing options at this time.
The European Environmental Agency is highly concerned with Li-ion batteries and how infrequently they are recycled. Research suggests only 5% of Lithium-ion batteries are recycled, which is an unsustainable in the long-term.
The polluting impact of mineral mining for lithium, cobalt, copper, and nickel are also problematic.
Faradion, a Na-ion battery producer located in Great Britain, was purchased by Reliance Industries for 100 million GBP.
Reliance plans to continue investing heavily in Sodium-ion battery systems and hopes to open gigafactories to produce these batteries. Additionally, the French company, TIAMAT, is looking to sell Sodium-ion batteries sometime in 2023.
The European market is expected to make a large push towards this transition to Na-ion battery systems within the next 5 years. Europe and China, current leaders in the EV market, will likely lead in this area.
Waiting for the Breakthrough
Expect to wait a few more years for a breakthrough that brings Sodium-ion batteries to technical and commercial maturity.
The battery chemistry needs further work to produce Sodium-ion batteries that can compete with the energy density found in Lithium-ion batteries.
There are no EVs that operate using Na-ion batteries at this time. But with the current pace of research, this could change very soon.