Synthesis of high-voltage spinel LiNi0.5Mn1.5O4 by Mn2O3 nanosheets for lithium-ion batteries with superior cycle life span

Abstract

The development of high-voltage cobalt-free spinel LiNi0.5Mn1.5O4 (LNMO) by conventional solid-state methods is hampered by its rapid capacity decay due to the impurity phases, inhomogeneous particle size, and dissolution of transition metals. To realize large-scale production and application of LNMO, a two-step modified solid-state method with Mn2O3 nanosheets as a precursor is proposed here. The resulting material (P-LNMO) shows a reduced rock salt impurity phase and enhanced ionic transport through a more uniform control of particle size. As a result, the cycling stability of the disordered LNMO is remarkably improved, where LNMO half-cell capacity retention is 89.5 % at ambient temperature after 1000 cycles. What's more, the LNMO/Graphite full-cell is further assembled showing a discharge specific capacity of 110 mAh g−1 at 1C, and remains 97 % of its initial capacity after 100 cycles. The excellent electrochemical performance indicates that this modified solid-state approach brings a new avenue to the synthesis of LNMO for the upcoming generation of commercial lithium-ion batteries.