Selective ion capture, separation and concentration

Description
The concept is based on the pumping of ions through an electrochemical cell made of ion-selective electrodes that can capture, separate and concentrate certain ions, for example, Lithium, Sodium and Potassium.Electrochemical cells with ion-selective electrodes can be used for pumping of ions from impure liquors to refined solutions. This involves ion capture, separation and concentration processes. The electrodes proposed for this technology derive from the active materials in metal-ion intercalation batteries, such as Li-ion, Na-ion and K-ion batteries. These active materials are conformed in a semi-solid flow design that allows the electrodes to be easily replaced when they reach the end of their lifetime. In addition, the thickness of the electrodes is adapted according to the required area capacity and allows different types of electrode materials to be injected depending on the demand of the separation process, showing great versatility. This versatility is enhanced by adjusting the cell configuration to symmetric and asymmetric architectures by using different ionic exchange membranes and depending on the type of inlet and outlet solutions processed.

Advantages and Innovations
The main advantages and innovations of the technology are:

• Electrodes are highly selective to specific ions that can be intercalated in their crystalline structure.
• The ion capture and release processes are very reversible, since they correspond to ion intercalation /de-intercalation phenomena in metal-ion batteries. This reversibility leads to energy efficient processes.
• The semi-solid design of electrodes allows injection and de-injection in the cell, thus facilitating the replacement at the end of their service life or if a change in the ion selectivity is required at any given time. This configuration also allows tailoring the mass loading of active material by making the electrode thinner of thicker on demand, therefore making ion pumping capacity to be tuneable to specific application requirements.

Market Applications:

• Water treatment. This concept has application in the field of water treatment from industrial process effluents. Particularly for valorisation of dissolved species.
• Primary and secondary raw materials. Potential users of the technology could also be companies that produce Lithium salts from brines of salt fields, lithium ores mining and recycling of Li-ion batteries.