Boron Nitride Nanotubes Surprise Physicists: They Transport Lithium 31 Times Faster

Scientists Discover Membrane That Could Transform Lithium Recycling and Clean Energy Production

Researchers from Rutgers University, University of Illinois Chicago, and Argonne National Laboratory have made a breakthrough that could revolutionize battery recycling and clean energy generation. According to a study published in the prestigious journal Nature Nanotechnology, membranes made from boron nitride nanotubes exhibit anomalously fast lithium-ion transport. The recorded ion flow was found to be as much as 31 times higher than predicted by conventional diffusion models.

Boron nitride is a synthetic crystalline compound. The researchers used it to create specialized membranes packed with millions of microscopic nanotubes. During testing, these nanostructures demonstrated the ability to selectively transport lithium ions at speeds that dramatically exceeded those of any other charged particles.

Inspiration from the Electric Eel

Professor Sangil Kim, one of the study’s lead authors, compared the observed mechanism to the way an electric eel generates electrical impulses through ion channels in its specialized cells. He noted that the ion transport rates measured in the experiment were significantly higher not only than theoretical predictions but also than those achieved by any previously reported laboratory system.

To evaluate the membranes in a practical setting, the researchers placed them between ionic solutions with different salinity levels. The resulting concentration gradient generated electrical energy capable of powering small electronic devices, including a watch, a calculator, and LED lights.

The study found that the power density per membrane pore reached as high as 15,300 watts per square meter, while the energy conversion efficiency at pH 5.5 approached the theoretical physical limit of 50%.

Lithium Recovery and Blue Energy Generation

The discovery by the team led by Semih Cetindag and Aaditya Pendse opens the door to commercial applications in two key areas:

• Efficient battery recycling – The exceptional speed and selectivity of the membranes in transporting lithium ions could enable the development of significantly faster and lower-cost methods for recovering lithium from spent lithium-ion batteries.
• Blue energy generation – The technology is ideally suited for harvesting osmotic energy. Such systems generate clean electricity where saltwater (for example, seawater) mixes with freshwater (such as river water at estuaries), utilizing the natural difference in salt concentration to produce power.

If successfully scaled up, this breakthrough could help address two major challenges simultaneously: securing critical lithium supplies through more effective recycling and creating a new source of renewable energy from naturally occurring salinity gradients.