UK researchers develop novel protein membrane to separate lithium and sodium for battery production

UK researchers are developing a new method that uses engineered proteins to extract lithium for batteries, with the proteins able to assemble into membranes with pores as small as 1 angstrom, potentially enabling separation of lithium from chemically similar sodium. The approach uses S-layer proteins, which naturally form highly ordered structures on microbial surfaces. Researchers aim to modify these proteins to create membranes with uniform pores capable of selectively separating lithium and sodium ions. Scientists from the University of Birmingham and Aston University are targeting pore sizes of 1 to 50 angstroms, where 1 angstrom equals one billionth of a meter.

The goal is to produce large-area membranes capable of highly selective separation under real-world operating conditions. The three-year program has received £6.2 million in funding from the UK's Advanced Research and Invention Agency (ARIA).

Membrane design and screening process

Researchers will design and screen thousands of protein variants, then scale the most promising candidates for membrane fabrication and testing. The proposed membranes will use S-layer proteins, which naturally form ordered two-dimensional structures on the surfaces of many microbes. These proteins can assemble into repeating patterns without individually positioning each component. Researchers plan to modify their structures to create pores with controllable size and chemical properties. Thousands of protein variants will be designed and screened to identify candidates capable of separating lithium and sodium ions. The most promising versions will be produced at larger scale and incorporated into membrane systems.

"Biology can build ordered materials with a precision that existing manufacturing methods struggle to achieve," said Dr. Dominik Kubicki, project lead at the University of Birmingham. "We aim to harness this to create membranes with uniform, programmable pores." Fold9 will handle computational protein design, while Adaptyv Bio will provide high-throughput screening to test large numbers of variants. UK-based Evove will contribute membrane fabrication, scale-up, and testing expertise. Researchers will also use cryo-electron microscopy (cryo-EM) and neutron reflectometry to examine nanoscale features of the membrane structure.

These techniques will help determine how variations in pore geometry affect ion selectivity, stability, and transport.

Challenges in scaling membrane manufacturing

Scaling membranes beyond the laboratory is a primary challenge. The team plans to combine protein production, membrane fabrication, and testing to evaluate whether these materials retain their selective properties when manufactured at larger scale. "A key challenge is translating molecular-level control into membranes that can be manufactured and operated at practical scale," said Professor Owen Thomas of the University of Birmingham. The project is part of ARIA's "Universal Manufacturer" program, which explores using engineered proteins as building blocks for manufacturing materials with controllable structures.

Although lithium extraction is the initial target, researchers believe this approach could ultimately support water treatment, critical mineral recovery, and chemical and pharmaceutical manufacturing.

The technology remains in the development stage. The team has not yet reported an industrial-scale membrane in operation, lithium recovery rates, or measured energy savings. The three-year program will test whether engineered proteins can deliver the selectivity, durability, and scalability required for practical separation systems.

Potential applications and challenges of novel protein membranes

This research demonstrates the potential of engineered proteins in battery production, particularly in the selective separation of lithium and sodium. By leveraging biology's precision, researchers hope to create membranes with controllable pores, which is crucial for improving battery efficiency. However, scaling laboratory technology to industrial scale remains challenging, especially in maintaining the membrane's selective properties. If successful, this technology could not only improve battery production but also play an important role in fields such as water treatment and mineral recovery, showing broad application potential.