Authored by Neetika Walter via Interesting Engineering,
Researchers at Rice University have developed a water-based method that recovers valuable metals from spent lithium-ion batteries in minutes, offering a faster and lower-energy alternative to conventional recycling systems.
The new process targets key battery materials including lithium, cobalt, nickel, and manganese, which are in growing demand as electric vehicle and electronics production expands worldwide.
Battery recycling is becoming increasingly important as mineral supply chains tighten and nations seek to reduce dependence on newly mined materials. But many current recovery methods rely on harsh acids, toxic solvents, or long processing times.
Rice researchers say their new class of aqueous “amino chloride” solutions can extract metals quickly while avoiding many of those drawbacks.
“Traditional recycling methods often rely on harsh acids or slow, energy-intensive processes,” said study first author Simon M. King. “What we’ve shown is that you can achieve rapid, high-efficiency metal recovery using a much simpler, water-based system.”
The team focused on hydrometallurgical recycling, in which battery metals are dissolved into a liquid and later separated for reuse. It is considered one of the more scalable approaches, but common solvents can create environmental and cost challenges.
To improve the process, the researchers tested several amino chloride salts as alternative leaching agents. One compound, hydroxylammonium chloride, or HACl, delivered the best results.
In testing, the HACl solution extracted about 65 percent of key battery metals in just one minute at room temperature. Recovery rates climbed above 75 percent for several metals with slightly longer treatment times.
That speed is notable because many recycling systems require elevated temperatures or extended reaction periods, both of which increase energy use and operating costs.
Water beats solvents
“We were surprised by just how fast the reaction occurs, especially without the involvement of high temperatures,” King said. “Within the first minute, we’re already seeing the majority of the metal extraction take place.”
Researchers said replacing traditional organic solvents with water lowered viscosity, allowing molecules to move more freely and accelerate reactions. Water-based chemistry also simplifies waste handling and may reduce environmental risks.
The team used experiments and modeling to understand why the solution performed so well. While acidity and chloride ions help dissolve metals, the researchers found that a built-in redox-active nitrogen center in HACl played a major role.
“While the rapid metal dissolution is very interesting, what is most exciting is that this highlights the generic chemical properties that are the major drivers for efficient leaching,” said Sohini Bhattacharyya.
“That redox capability gives it a major advantage over other similar systems we tested.” After extraction, the recovered metals were reprocessed into new battery materials, demonstrating a closed-loop recycling pathway.
The findings could help shape next-generation battery recycling plants by combining low-toxicity solvents with targeted chemistry that boosts speed and efficiency. With EV battery waste expected to rise sharply in the coming years, faster recovery methods may become increasingly valuable.
The study was published in Small.