As electric vehicles surge worldwide, used battery packs are fast becoming one of the largest—and most valuable—waste streams. Extracting lithium from old batteries is notoriously expensive and energy-intensive, with most recycling methods relying on high-temperature smelting or aggressive acid leaching to produce lithium carbonate that still needs additional conversion into lithium hydroxide for reuse.
Researchers at Rice University have unveiled a new “recharge-to-recycle” reactor that flips this process on its head—literally. Instead of breaking down spent materials with chemicals, the system recharges them to extract lithium directly in the form manufacturers actually need: battery-grade lithium hydroxide.
“We asked a basic question: If charging a battery pulls lithium out of a cathode, why not use that same reaction to recycle?” said Sibani Lisa Biswal, chair of Rice’s Department of Chemical and Biomolecular Engineering. “By pairing that chemistry with a compact electrochemical reactor, we can separate lithium cleanly and produce the exact salt manufacturers want.”
In a conventional battery, charging moves lithium ions from the cathode to the anode. The Rice system applies this same principle to waste cathode materials—such as lithium iron phosphate (LFP)—allowing lithium ions to migrate through a selective membrane into a stream of water. At the same time, the counter electrode splits water to produce hydroxide ions. The lithium and hydroxide combine in the water to form high-purity lithium hydroxide, all without acids, solvents, or extra reagents.
Published in Joule, the research describes a zero-gap membrane–electrode reactor that operates using only electricity, water, and shredded battery waste (“black mass”). In one mode, the process consumed just 103 kilojoules of energy per kilogram of waste—roughly ten times less than typical acid-leaching routes, even before accounting for additional refining steps.
The team scaled the device to 20 cm², successfully ran it for 1,000 continuous hours, and processed 57 grams of industrial black mass supplied by industry partner TotalEnergies. The system maintained nearly 90% lithium recovery and produced lithium hydroxide that was over 99% pure, suitable for direct reuse in new batteries.
“Directly producing high-purity lithium hydroxide shortens the path back into new batteries,” said Haotian Wang, Rice associate professor and co-corresponding author. “That means fewer processing steps, lower waste, and a stronger, more circular supply chain.”
The method proved adaptable across multiple chemistries, including LFP, lithium manganese oxide, and nickel-manganese-cobalt (NMC) cathodes. Even more impressively, the team demonstrated roll-to-roll processing of entire LFP electrodes directly from aluminum foil—no scraping, shredding, or chemical pretreatment required.
“The roll-to-roll demo shows how this could plug right into automated disassembly lines,” Wang added. “You feed in the electrode, power the reactor with low-carbon electricity, and draw out battery-grade lithium hydroxide.”
Next, the Rice team plans to scale up with larger reactor stacks, higher black mass loading, and new hydrophobic membranes designed to sustain efficiency at greater lithium hydroxide concentrations. They’re also targeting posttreatment steps like concentration and crystallization to further cut energy use and emissions.
“We’ve made lithium extraction cleaner and simpler,” Biswal said. “Now we see the next bottleneck clearly. Tackle concentration, and you unlock even better sustainability.”
Source: Rice University News – “New Recharge-to-Recycle Reactor Turns Battery Waste into New Lithium Feedstock
