Lithium-ion batteries - Electrolytes

Battery electrolytes are responsible for the ionic mass transport between the electrodes upon charge and discharge, and fast ionic transport are therefore of high importance. However, the good transport properties in conventional liquid electrolytes often result in inferior safety due to side-reactions between the electrode and electrolyte materials. Solid electrolytes are therefore preferred in many applications, not least polymer electrolytes which are formed by mixing an lithium salt in for example poly(ethylene oxide) (PEO).

Our research activities in the area of polymer electrolytes today have a focus on Molecular Dynamics (MD) simulation. With the dramatic increase that has occurred in supercomputer power in recent years, we have reached the point where “computer-based experiments” give us true insights into complex processes at an atomic level. The calculations themselves are highly time-consuming, often taking longer than the average laboratory experiment. On the other hand, they are able to probe situations and reach fundamental insights which are virtually inaccessible experimentally.

Our research efforts – both experimentally and theoretically – in the electrolyte field also consists of electrolytes for other applications, such as polymer membrane fuel cells or artificial muscles. Current activities involve:

• MD simulations of PEO-based electrolytes to fundamentally investigate ionic transport processes in for example crystalline or branched polymer systems.
• Ultra-thin electrolytes for micro-batteries.
• Increased battery safety by electrolyte additives.
• Temperature sensitive polymer electrolytes.
• MD simulations of proton conductive polymer systems for fuel cells.
• MD simulations of ionically conductive electroactive polymers for artificial muscles.