Indian scientists at BARC have developed a groundbreaking technique to extract lithium from seawater with 90% efficiency,
This offers a potential solution to India's reliance on lithium imports for EVs and energy storage.
The method uses fewer chemicals and solvents, making it cost-effective and environmentally friendly.
However, commercial scalability and ecological impacts remain key challenges.
In a scientific breakthrough that can offer the much-needed impetus to India’s energy transition efforts, scientists at Bhabha Atomic Research Centre (BARC) have developed a chemical technique that can extract nearly 90 per cent of the lithium dissolved in natural seawater.
The global shift towards electric transport and renewable energy is driving unprecedented demand for lithium (Li). Lithium-ion batteries remain the dominant energy storage technology due to their high energy density, long cycle life and operational reliability.
India relies entirely on imports for raw lithium and battery-grade lithium-ion cells, leaving its rapidly growing electric vehicle (EV) and energy storage sectors vulnerable to shifts in global markets.
Seawater is the world’s largest reservoir of lithium, containing an estimated 230 billion tonnes of the metal. Yet extracting it is difficult. Lithium occurs at extremely low concentrations—about 0.17 mg per litre—while the ratio of magnesium to lithium exceeds 6,000. This makes selective extraction challenging. Processing the enormous volumes of water required also makes material and energy efficiency critical to the process’s viability.
Researchers have explored various direct lithium extraction technologies to overcome these obstacles. But existing methods can suffer from slow extraction rates, structural degradation and complicated regeneration processes. Many also require expensive chemicals, large volumes of solvents and complex processing.
The technique, developed by Vatsal Trivedi, Sai Krishna Devulapally, R Shekhar and G Venkateswarlu at BARC’s National Centre for Compositional Characterization of Materials in Hyderabad, requires fewer additional chemicals and considerably less solvent. The findings have been published in the journal Talanta.
The researchers began by treating seawater with a specialised chemical process. They gradually raised its pH using sodium hydroxide and sodium carbonate, helping to remove unwanted elements such as magnesium and calcium.
According to the study, the process removed more than 99 per cent of these interfering elements while retaining most of the lithium in the water. This is a crucial step: removing other elements without losing significant amounts of lithium is one of the main challenges in developing an efficient extraction technique.
The researchers then used an organic compound called dibenzoyl methane, dissolved in a solvent known as methyl isobutyl ketone (MIBK), to help extract the lithium.
One of the technique’s key features is its low solvent consumption. The researchers achieved an organic-to-aqueous phase ratio of 0.1, meaning that they used about 100 ml of organic solvent for every litre of treated water.
Conventional extraction techniques often require additional chemicals, increasing costs and generating chemical waste. In the new method, MIBK serves not only as a solvent but also helps stabilise the chemical complexes formed with lithium, reducing the need for separate additives.
The researchers also found that the duration of contact between the water and the solvent significantly affects the results. Mixing the two for the right amount of time improves lithium extraction efficiency.
The researchers used dilute nitric acid to separate the lithium from the solvent. This transfers the lithium into a separate solution, leaving the organic solvent available for reuse.
Tests over five cycles maintained a lithium recovery rate of about 90 per cent, suggesting that the solvent can be reused. However, the researchers also reported physical losses of roughly 10 per cent of the solvent in each cycle, which would need to be replenished.
The technique shows promise, but several questions must be answered before it can be adopted commercially. Researchers will need to assess its long-term performance, energy requirements, chemical costs, environmental effects on marine ecosystems and feasibility at industrial scale. Prolonged mixing may also cause persistent layers of foam to form, posing a further challenge.
Even so, the research points to a potential new source of lithium. If the process can be scaled up affordably and with minimal environmental harm, seawater could become an additional source of the metal. This could help ease pressure on conventional mining and expand supplies of the raw materials needed for electric vehicles and energy storage.
The road to unlocking this hidden marine resource remains long. But the work of Indian scientists suggests that the future of clean energy may depend not only on what lies beneath the ground, but also on what is dissolved in the oceans.