Mangrove Lithium Cuts Waste in Battery Production

As electric vehicles roll off assembly lines, a bottleneck sits upstream: lithium refinement. Turning raw lithium into the compounds needed for batteries is expensive, messy, and energy-intensive, but Mangrove Lithium, a Vancouver-based startup, has a better way. The company has developed an electrochemical refining process that converts lithium feedstocks into battery-grade lithium hydroxide.

Converting raw lithium to lithium hydroxide typically requires roasting spodumene—a mineral from which lithium is derived—at high temperatures, and then leaching it with acid to convert it to lithium sulfate. That compound then needs to be converted to lithium hydroxide. “It’s a thermochemical reaction that uses heavy amounts of reagent chemicals, and generates a sodium sulfate waste stream,” says Ryan Day, Mangrove Lithium’s director of operations.

Further tightening the bottleneck, the majority of the world’s lithium—60 to 70 percent—is now refined in China, and export restrictions and geopolitical tensions have disrupted supply chains in recent years. Shipping raw lithium overseas to be refined also adds to batteries’ total carbon footprint. A new model for lithium refining could reshape not just the economics of electric vehicles, but the geography and environmental footprint of the global battery supply chain.

Mangrove’s demo plant in British Columbia is scheduled to start production in the second half of 2026.

How Does Mangrove’s Refinement Work?

Mangrove replaces the conventional, resource-intensive reaction with a process that uses electricity, water, and oxygen. In an electrochemical cell, they flow brine through an electrolyzer, which consists of a metal box with three compartments between the cathode and anode. The compartments are separated by ion exchange membranes, semipermeable barriers that only allow certain ions to pass. Lithium sulfate flows through the central compartment, and the cell’s electric field splits the salt apart. “Lithium, which is a positive ion, will move across a membrane toward the cathode,” says Day. There, “we are reacting oxygen and water to create hydroxide ions, which join with the lithium from the salt to make lithium hydroxide.”

Meanwhile, on the opposite side of the cell, the sulfate—a negative ion—moves towards the anode, where water is being split to produce protons and oxygen gas. The protons combine with sulfate ions to make sulfuric acid.

“You run that process continuously, and over time you’re generating lithium hydroxide, which you can send to a crystallizer,” Day says. “There’s no significant waste product and all you’re feeding in is brine, water, oxygen, and electricity.” The sulfuric acid is recovered and can be circulated back upstream to leach more brine from the raw feed material.

In general, keeping the ion exchange membrane intact is one of the biggest challenges for scaling this type of process, says Feifei Shi, assistant professor of energy engineering at Penn State. Shi, who researches electrochemical-based refinement methods, notes that the approach can more easily activate the necessary reactions, but faces limitations for large-scale applications.

The electrochemical process separates out lithium by passing it through three compartments separated by semipermeable barriers. Mangrove Lithium

Mangrove’s Oxygen-Based Cathode

Mangrove’s key innovation and what enables the process is an oxygen-based cathode. “Driving the reaction requires detailed engineering,” says Day. The company designed an electrode that lets a gas and a liquid react together, using just enough water to make the oxygen reaction work—without adding so much that it floods the system and creates hydrogen gas instead.