For more than 40 years, Stanislav Filatov, Professor at St Petersburg University, together with colleagues from other research institutions in Russia, has been studying the mineralogy of Kamchatka. The peninsula sits atop the tectonic border between the Russian continental plate and the oceanic plate of the Pacific. Blobs of magma rising upwards along the border feed a chain of volcanoes, including Tolbachik Volcano, which experienced two major eruptions in 1975-1976 and 2012-2013. In recent years, researchers have discovered dozens of new minerals here.
In a recent paper, the Russian mineralogists described another new mineral from this volcano, displaying a unique crystal structure. Petrovite occurs as blue globular aggregates of small tabular crystals near active fumaroles, emitting hot volcanic gases and steam. The mineral is named in honor of Dr. Tomas Georgievich Petrov for his contributions to mineralogy and crystallography and, in particular, for the development of technology for the industrial fabrication of jewelry malachite.
The mineral consists of oxygen, sulfur and copper atoms, which form a porous framework. Smaller atoms, like sodium, can move freely through the crystalline structure using the voids and channels in the framework as passages. This unique property could be used as a template for creating more efficient batteries.
Modern sodium-ion batteries (NIB), a type of rechargeable battery, use sodium ions (Na+) as the charge carriers. As the sodium atoms moving through the battery provide the electrical charge, engineers are interested in using materials with a low resistance to build more efficient batteries. As petrovite contains traces of copper, it can’t be used in batteries in its natural state. However, according to Filatov, synthetic materials copying the crystalline structure of petrovite and replacing the copper with other elements could lead to the development of more efficient batteries.