What Exactly Are Sodium-Ion Batteries?
At a fundamental level, sodium-ion batteries work much like the lithium-ion batteries powering our phones and current electric vehicles. They store and release energy by moving ions between a positive electrode (cathode) and a negative one (anode). The key
difference, as the name suggests, is the ion itself. Instead of lithium, this emerging technology uses sodium—an element that is over 1,000 times more abundant on Earth. The basic principle is the same, but this simple substitution of a common material for a rare one has profound economic and geopolitical implications. While lithium is concentrated in a few countries, leading to volatile pricing and supply chain risks, sodium can be sourced from common salt, making it universally available and significantly cheaper.
The All-Important Cost Advantage
The primary driver behind the excitement for sodium-ion technology is cost. Lithium, nickel, and cobalt—key ingredients in many lithium-ion cells—are expensive and subject to market fluctuations. Sodium-ion batteries eliminate the need for all three. Because sodium is so plentiful, the raw material costs are dramatically lower. Furthermore, manufacturing can be done on existing lithium-ion production lines, which avoids the need for a complete retooling of factories and helps accelerate commercialisation. This combination of cheaper materials and compatible manufacturing is what promises to bring down the overall price of a battery pack, which is currently the single most expensive component of an EV, often accounting for around 40% of its total cost. Analysts predict that sodium-ion batteries have the potential to be 40-50% cheaper than their lithium-ion counterparts.
Performance, Range, and Limitations
So, if they are so much cheaper, why aren't all EVs using them? The trade-off comes down to energy density. Sodium ions are larger and heavier than lithium ions, which means sodium-ion batteries currently store less energy per kilogram. While top-tier lithium-ion batteries can reach energy densities of 240-350 Wh/kg, current commercial sodium-ion cells are in the 100-175 Wh/kg range. This makes them less suitable for long-range, high-performance luxury EVs. However, this density is comparable to that of Lithium Iron Phosphate (LFP) batteries, which are already widely used in many standard-range EVs. Their sweet spot is in applications where extreme range is not a priority: affordable city cars, two- and three-wheelers, and commercial fleet vehicles. An added advantage is their excellent performance in extreme temperatures, retaining up to 90% of their capacity even at -40°C, a significant weakness for many lithium-ion chemistries.
Key Players and the Indian Landscape
Globally, Chinese giants like CATL and BYD are leading the charge. CATL has already started mass production, with its batteries appearing in models from automakers like Chery and GAC Aion in 2026. BYD is also heavily invested, constructing a massive 30 GWh sodium-ion plant. India is not standing still. Reliance Industries made a significant move by acquiring UK-based sodium-ion pioneer Faradion for $135 million, with plans to commercialise the technology. Several homegrown startups are also making impressive strides. Roorkee-based IndiEnergy is developing cells using hard carbon derived from agricultural waste, a true 'Make in India' innovation. Pune-based Rechargion, a spin-off from the National Chemical Laboratory, is also developing its own cells targeting the two- and three-wheeler market. These companies are crucial for building a self-reliant Indian EV ecosystem.
