By 2030, the European Union is planning to limit greenhouse gas emissions by 50%, with the intention of being environmentally neutral by 2050. To make it happen, it is necessary to design efficient storage systems of energy from renewable sources.

Currently, Li-Ion batteries are most widely used for energy storage. However, many materials used for their production (Li, Co, Ni, graphite) are nowadays considered to be critical and their prices are constantly growing. For this reason, in her doctoral thesis, Natalia Izdebska, MSc, from the Faculty of Chemistry at WUT, focused on batteries based on widely available, cheap and safe materials, i.e. Mg and Ca.

Both magnesium and calcium are among the 10 most common elements in the earth’s crust. These metals exchange two electrons per atom during the electrochemical reaction, resulting in high theoretical gravimetric and volumetric capacities. Most importantly bivalent metals are less prone to dendrite creation than lithium because of lower self-diffusion barriers. This makes the use of bivalent metal anodes safer compared to lithium. However, magnesium is easily covered with a biotin-insulating passive layer on the metal surface and participates in the reactions of charge transfer at a lower degree. However, magnesium easily forms a passive insulating layer on the metal surface, which significantly restricts its participation in charge transfer reactions.

Izdebska’s doctoral thesis aims to increase the capacity of batteries based on bivalent metals (Mg, Ca) through the use of electrolyte additives. The main research hypothesis made by the PhD candidate is based on research studying the interactions of chelating additives with metal cations and salt anions.

Such additives can be tailored and are easy to modify. Their design process can be compared to building blocks: from a whole selection of groups modifying the molecule structure, it is possible to select those that will produce the desired outcomes and add them to the base molecule, exactly as if we were adding building blocks to a larger structure. Such additions can promote the formation of magnesium ions and facilitate their charge transfer in the battery.

Project: “Additives for high energy batteries based on bivalent metal ions and an organic cathode” is financed by the National Science Centre (OPUS 22 LAP no. 2021/43/I/ST4/02521).

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