Cheap electric vehicles, but potential chemical concerns with CATL's salt battery technology?
In a significant move for the battery industry, CATL, the Chinese battery giant, has begun mass production of a 24V start-stop integrated sodium-ion battery for heavy-duty trucks. This development comes as CATL expects these batteries to offer a greater cost advantage over their current lithium iron phosphate (LFP) offerings.
Energy Density and Cost
Sodium-ion batteries trade off energy density for cost savings and material abundance. Compared to nickel-cobalt-manganese (NCM) lithium-ion cells, which typically have the highest energy density, sodium-ion batteries have lower energy density. LFP cells, on the other hand, operate at a lower voltage and have lower energy density than NCM but maintain an advantage in safety and lifespan.
The lower energy density of sodium-ion batteries is due to their larger ionic radius and a relatively low average operating voltage of around 3.2 volts per cell. However, they benefit from abundant, inexpensive materials, resulting in lower production cost and less exposure to cobalt and nickel supply chain risks. LFP batteries also use iron and phosphate, which are abundant and cheap, making them less expensive than NCM.
Commercial Viability
LFP batteries are currently the dominant chemistry in many markets, particularly China, for electric vehicles due to their low cost, superior safety, and long cycle life. NCM batteries remain preferred where higher energy density is required, such as premium EVs and performance applications.
Sodium-ion batteries are emerging as a promising low-cost alternative, particularly for grid-scale storage where energy density is less critical. As technology matures, commercial adoption is expected to grow.
Safety
LFP batteries are known for their excellent thermal stability and safety, with very low risk of thermal runaway or fires compared to nickel-based chemistries like NCM. Sodium-ion batteries are also expected to offer good thermal stability and safer profiles than conventional lithium-ion batteries but require further commercial validation.
Global Market Outlook
The global sodium-ion battery market is projected to grow from $18.2 billion in 2025 to $203.2 billion by 2032, reflecting more than tenfold growth over the period. This growth is driven by the potential of sodium-ion batteries to offer commercial viability in cost-sensitive segments.
Other battery manufacturers, such as Samsung SDI and SK On, are still exploring potential development paths for sodium-ion batteries. Only LG Energy Solution among Korean battery makers is aiming for sodium-ion battery commercialization for uninterruptible power supplies and EVs by 2030.
Challenges Ahead
Replacing lithium-ion cells with sodium-ion batteries remains a challenge. However, the manufacturing process for sodium-ion and lithium-ion cells is largely exchangeable, potentially lowering equipment costs for the new battery chemistry. A senior researcher views sodium batteries as one of many next-generation battery technologies, not necessarily as direct replacements for LFP or NCM.
CATL's "Naxtra" battery for passenger vehicles, scheduled for launch in December, has an energy density of 175 watt-hours per kilogram and a range of 500 kilometers on a single charge. This battery offers exceptional performance in cold weather, surpassing that of existing lithium-ion technologies.
However, it's important to note that CATL's sodium-ion battery primarily designed for starting engines or powering auxiliary systems in internal combustion engine vehicles, not for driving fully electric heavy trucks.
The launch of CATL's sodium-ion battery poses a challenge for Korean battery manufacturers who have yet to begin mass production of LFP cells for EVs. SK On CEO and President Lee Seok-hee stated the need to closely monitor technological trends in sodium-ion cells for the budget-friendly EV market.
In conclusion, while sodium-ion batteries offer a promising cost advantage and are expected to play a significant role in grid storage and budget-friendly EVs, they still face challenges in replacing lithium-ion batteries in high-energy-density applications.
References:
- https://www.sciencedirect.com/science/article/pii/S2468004621001311
- https://www.nature.com/articles/s41536-020-00266-w
- https://www.sciencedirect.com/science/article/pii/S2405450020303100
- https://www.sciencedirect.com/science/article/pii/S2468004620303559
- The mass production of CATL's 24V start-stop integrated sodium-ion battery for heavy-duty trucks represents a shift towards technology that aims to offer a greater cost advantage over current lithium iron phosphate (LFP) offerings, as sodium-ion batteries are known for their lower production cost due to the abundant and inexpensive materials they use.
- As the global sodium-ion battery market is projected to grow significantly over the next decade, other battery manufacturers, such as Samsung SDI and SK On, are exploring potential development paths for sodium-ion batteries, recognizing their potential as a low-cost alternative, particularly for cost-sensitive segments like grid-scale storage and budget-friendly electric vehicles.
