Oxidative dissolution of lithium and manganese from lithium manganospinel (LiMn2O4): towards climate-smart processes for critical metal recycling

Abstract

This work reports the oxidative breakdown of the LiMn₂O₄ structure using alkaline hypochlorite, as a method for recovering both lithium and manganese species. The heterogeneous dissolution rate for this process is monitored through the formation of the permanganate ion. It is found that reaction occurs under activation control, with a barrier that matches that for electron hopping within the spinel. Moreover, this activation barrier is smaller than those observed for typical conventional methods of recovery of lithium or manganese from LiMn₂O₄; accordingly, the new process is suggested to be climate-smart, despite the low, single-pass, recovery efficiency that results from slow surface kinetics.