  The expected shortage of Li due to the strong increase in electromobility is
an important issue for the recovery of Li from spent Li-ion batteries. One
approach is pyrometallurgical processing, during which ignoble elements such as
Li, Al and Mn enter the slag system. The Engineered Artificial Minerals (EnAM)
strategy aims to efficiently recover critical elements. This study focuses on
stabilizing Li-manganates in a synthetic slag and investigates the relationship
between Mn4+ and Mg and Al in relation to phase formation. Therefore, three
synthetic slags (Li, Mg, Al, Si, Ca, Mn, O) were synthesized. In addition to
LiMn3+O2, Li2Mn4+O3 was also stabilized. Both phases crystallized in a
Ca-silicate-rich matrix. In the structure of Li2MnO3 and LiMnO2, Li and Mn can
substitute each other in certain proportions. As long as a mix of Mn2+ and Mn3+
is present in the slag, spinels form through the addition of Mg and/or Al.
