Electrolyte for magnesium batteries
Nowadays, modern electrical appliances almost exclusively run on lithium-ion accumulators. As yet, a rechargeable electric energy store that could compete with these accumulators regarding power density and longevity has not been developed. However, the lithium-ion accumulators do have their limitations. Lithium, a natural resource, is not indefinitely available. Furthermore, the lithium accumulators require protective circuits since they are sensitive to over-discharge and exhaustive discharge. For some time, scientists have therefore been attempting to produce energy stores using magnesium, which is cheap and does not harm the environment. Magnesium has the potential to provide a power density per volume almost twice as high as that of lithium.
State of the art
However, a special electrolyte that acts as an ion-conducting system between the electrodes is required for the reliable operating of a magnesium accumulator system. If an electrolyte produced using the conventional approach were to be employed, on the anode, which consists of magnesium, it would create a film that inhibits conductivity and prevents a reversible operating of the accumulator. It would be desirable to use sulphur as a cathode in magnesium cells as well. However, in the magnesium electrolytes developed so far, it would decompose.
Scientists at the KIT Institute for Nanotechnology (INT) and Helmholtz Institute Ulm (HIU) have now developed an electrolyte that bypasses these effects. The inputs are aluminium chloride and magnesium hexamethyl di-silicide, which react with one another in an organic solvent and form the electrolyte. The products do not have to be isolated or purified. Thus the manufacture of the chemical compound can be achieved in a simple, one-step procedure yielding a high concentration. The electrolyte is electrochemically stable and has a high level of efficiency.
The electrolyte developed at KIT could represent an important step towards manufacturing long-life, high-performance magnesium batteries. The raw materials are readily available and have favourable environmental properties.
Options for companies
KIT is looking for partners to elaborate and apply the technology.
Your contact person for this offer
Dr. Aude Pélisson-Schecker,
Karlsruhe Institute of Technology (KIT)
Innovation Manager Energy, Innovation and Relations Management (IRM)
Phone: +49 721 608-25335