Constructing partially spinel phase in Mn-rich cathode material

Abstract

As a cathode with earth-abundant element, Mn-rich oxide has been explored to enable the scaling of the Li-ion battery. However, the irreversible transition metals migration and phase transformations in Mn-rich materials have been proven to be detrimental, which trigger capacity degradation, voltage decay, and poor kinetics. In this work, using Li2MnO3 as model, spinel-layered biphase was constructed via Ti doping and de-lithiation modification, which exhibits higher available capacity of 236.9 mAh/g (55.6 mAh/g for pristine material) and improved rate performance. Compared with pristine Mn-based cathodes, the new phase delivers neglectable voltage degradation during electrochemical cycling. Based on systematic characterization, the new phase exhibits higher oxygen redox reversibility and accelerated kinetics of lithium ions transformation. This work provides a new strategy for designing high-energy density Mn-rich cathodes.