Heterogeneous Atoms Substituted Rock Salt Phase Mn1‐xFexO Solid Solution with Rich Defects for Advanced Lithium‐Ion Batteries

Abstract Heterogeneous atoms substitution is an efficient method for promoting Li + storage of transition metal oxides. Herein, a series of Fe‐substituted MnO solid solutions with different Fe contents are synthesized by a feasible solid‐phase method. The synergistic effects between heterogeneous atoms and rich vacancies are synchronously obtained, which hold distinctive electronic structures and substantial active sites. When optimized Mn 0.55 Fe 0.45 O solid solution as anodes for lithium‐ion batteries, pre‐prepared electrodes exhibit reversible lithium storage of 1286.9 mAh g –1 at 1 A g −1 after 400 cycles and even 628.1 mAh g –1 at 2 A g –1 after 1000 cycles. The LiCoO 2 //Mn 0.55 Fe 0.45 O full cells are assembled, achieving the reversible capacity of 130.2 and 111.3 mAh g –1 after 150 cycles at 0.1 and 0.2 A g –1 , respectively. Density functional theory calculations also authenticate that the electrochemical activity can be markedly boosted by the heterogeneous atoms substituted Mn 1 ‐x Fe x O solid solution.