Enhancing performances of Co-free Li-rich Mn-based layered cathode materials via interface modification of multiple-functional Mn3O4 shell

Abstract

• Construct Mn 3 O 4 protective shell to alleviate Jahn-Teller distortion. • Oxygen vacancy can effectively restrain the release of oxygen. • The designed LRNMO@Mn 3 O 4 cathode has higher electron/ion conductivity. • The Mn 3 O 4 -coated electrode exhibited excellent cycle stability. Herein, we put forward a feasible interfacial modification strategy in virtue of Mn 3 O 4 surface coating to construct protective shell and alleviate Jahn-Teller distortion during the charge/discharge process. It has been found that the increase of the oxygen vacancy on the surface of Li 1.2 Ni 0.27 Mn 0.54 O 2 of (LRNMO) after Mn 3 O 4 protective layer modification can effectively restrain the release of oxygen and enhancing rate capability, and thus improving its comprehensive electrochemical performances. In particular, the initial coulombic efficiency of the optimized LRNMO-1 electrode is improved from 72.3% to 84.3%. The capacity retention rate is up to 95.6% at 250 mA g −1 (1C) after 200 cycles. In addition, the LRNMO-1 electrode also has a good capacity retention rate (96.4% after 100 cycles) at a high current density of 5C. Moreover, the designed LRNMO@Mn 3 O 4 cathode exhibits higher ionic conductivity and better interface stability. As a result, this work offers a practicable and valuable exploration for the development and industrialization of Co-free Li-rich Mn-based cathode materials with high energy density.