In recent years, lithium prices have been on a roller coaster ride, bringing a technology that had previously been relatively low-key back into the spotlight: sodium-ion batteries. They look almost identical to lithium-ion batteries, but they have the potential to reshape the energy storage landscape without relying on lithium resources.

I. Sodium and Lithium: Close Relatives

The operating mechanism of sodium-ion batteries is virtually identical to that of lithium-ion batteries; both rely on ions shuttling back and forth between the anode and cathode. The biggest difference is that sodium accounts for about 2.3 percent of the Earth’s crust—more than 2,000 times the proportion of lithium—and is distributed extremely evenly, eliminating the risk of supply constraints caused by a few specific countries.

Indicators Sodium ion Lithium Iron Phosphate Ternary Lithium
Energy Density Approximately 100–160 Wh/kg Approximately 160–200 Approximately 250–300
Performance at Low Temperatures Still usable at −40°C Generally Weaker
Raw Material Dependency Sodium, adequate Lithium, Phosphorus Lithium, Nickel, Cobalt
Theoretical Cost 20–30% lower Chinese High

II. What Are Its Strengths?

Since sodium ions have a larger radius and are heavier than lithium ions, sodium-ion batteries naturally cannot match the energy density of lithium-ion batteries; this also means they are not well-suited to take the leading role in long-range passenger vehicles. However, they excel in terms of cost, low-temperature performance, and safety, and actually thrive in applications where volume and weight are not critical considerations.

III. Energy Storage Is the Most Comfortable Solution

Grid energy storage, backup power for cell towers, low-speed vehicles, and two-wheeled vehicles—in these applications, weight is of little concern, but cost and winter performance are critical. Sodium-ion batteries continue to function at temperatures as low as minus 30 to 40 degrees, effectively addressing the shortcomings of lithium iron phosphate batteries. CATL released its first-generation sodium-ion batteries in 2021, and its second-generation version in 2024 achieved an energy density of approximately 200 Wh/kg and low-temperature performance down to minus 40 degrees Celsius; the company is already moving toward large-scale production.

Don’t think of sodium-ion batteries as a replacement for lithium-ion batteries; it’s more accurate to say they have different roles: lithium-ion batteries are used where high energy density is required, while sodium-ion batteries are used where low cost, safety, and cold-weather performance are needed.

As energy storage shifts from a question of “whether it exists” to “whether it’s affordable,” sodium-ion technology—which doesn’t rely on scarce resources and can lower the cost per kilowatt-hour—has naturally disrupted that market worth hundreds of billions.