Sodium-ion batteries promise cheap energy storage—what is still missing?
Cheap and safe: sodium-ion batteries are a promising energy storage technology, both for stationary storage and mobility purposes.
Published on January 20, 2025
Sodium-ion batteries are emerging as a promising alternative to traditional lithium-ion counterparts. These batteries utilize sodium, which is both plentiful and cheap, making them a viable solution for cost-effective production and large-scale energy storage. Despite their lower energy density, sodium-ion batteries are particularly suitable for applications like affordable electric vehicles and home energy storage.
Recent advancements have addressed challenges such as durability issues, with researchers proposing modifications to enhance battery chemistry. In collaboration with Chinese manufacturers like CATL and BYD, the development of these batteries has gained momentum, potentially powering a significant portion of global electric vehicles by 2033. However, some bottlenecks remain to make them market-competitive
What are sodium-ion batteries?
Sodium-ion batteries (SIBs) represent a technological shift in energy storage, replacing the scarce lithium with abundant sodium as the cathode material--the cathode is the negative electrode of a battery. Sodium is the sixth most abundant element on the Earth's crust and can be primarily found in compounds such as common salt.
The appeal is clear: sodium is approximately 50 times cheaper than lithium and can be harvested from seawater, making it a sustainable choice for large-scale energy storage applications. Recent research at the University of Houston has demonstrated significant improvements, with a new material achieving higher energy densities—the quantity of energy stored in a kilogram of a given material—of 458 Wh/kg, marking a 15.657% increase over previous generations.
The world's largest sodium battery and AI benchmarks: this week's global innovation news
Every week we wrap up for you a selection of innovation news from all over the world. Here is what struck with us the most last week.
Sodium-ion technical challenges
Despite the advancements, sodium-ion batteries still face challenges. One of the main ones is purely physics. Sodium mass is three times greater than lithium's, making sodium less energy dense by about 30%.
Another hurdle facing sodium-ion technology has been its durability, particularly related to atomic reshuffling during operation, known as the P2-O2 phase transition. However, researchers at Cornell University have made significant progress in understanding these mechanisms, modifying the battery structure. The aforementioned research at University of Houston also allows for smoother ion movement while maintaining stability during charging and discharging cycles.
Breakthrough: solid-state battery hits 25% energy density gain
A European consortium announced the release of a solid-state battery capable of providing a higher energy efficiency than lithium-ion modules.
Current battery market dynamics
Nowithstanding chepear raw materials to make sodium-ion batteries, lithium-ion options dominate the merket. In 2024, the price of lithium-ion battery packs saw a 20% drop, the steepest annual fall since 2017, according to BloombergNEF. Manufacturing overcapacity, economies of scale, and wider adoption of lithium iron phosphate (LFP) batteries (a cheaper alternative to lithium-ion ones) are the drivers behind this fall. What can make sodium-ion batteries competitive?
According to the Stanford University-led STEER program, which has evaluated over 6,000 scenarios for sodium-ion battery competitiveness, the technology's success will require more than just scaling production. Innovation in engineering will be crucial for reducing costs. The recent Chinese restriction on graphite exports in December 2024 might accelerate the adoption of sodium-ion technology as manufacturers seek alternatives to traditional lithium-ion batteries.
As sodium-ion batteries continue to evolve, we can expect to see their manufacturing scaling up, and more of them powering electric vehicles (EVs). The lower cost, the improved safety, and the potential to set resilient supply chain—that don't necessarily depend on one country only as it is in the case of China with lithium— are elements that suggest they will play a role in the future. Particularly to alleviate pressure on the critical minerals supply allowing to diversify EVs battery chemistries and easing the green energy transition.