Fig. 3: Magnetic periodic table of battery materials.

a Reduced periodic table depicting the magnetic properties of various elements, including those of selected ions commonly used for batteries. The lower part depicts the low- and high-spin configurations of selected positive electrode transition metals in various oxidation states. The transition metals are assumed to be octahedrally coordinated with the oxygen ions, which is consistent with the case of the layered oxides and LiFePO₄. b Magnetic susceptibility of Li_xCoO₂ with different charge states obtained by electrochemically cycling a liquid-state battery with Li_xCoO₂ at the positive electrode, as described in Supplementary Section S1. We note that structural and compositional degradation occurs for x <½, which causes additional phases to form beyond Li_xCoO₂. c Magnetic susceptibility of various elements of relevance to batteries.