Cooperation of Fe 2 O 3 @C and Co 3 O 4 /C subunits enhances the cyclic stability of Fe 2 O 3 @C/Co 3 O 4 electrodes for lithium‐ion batteries

Summary A Fe 2 O 3 @C/Co 3 O 4 hybrid composite anode is synthesized via a two‐step hydrothermal method in which the acetylene carbon black component serves as a conductive matrix and as an effective elastic buffer to relieve the stress from Fe 2 O 3 @C and Co 3 O 4 /C during the electrochemical testing. The crystallinity, structure, morphology, and electrochemical performance of the composites are systematically characterized. Galvanostatic charge/discharge measurements of Fe 2 O 3 @C/Co 3 O 4 present the excellent rate performance and cyclic stability. Its reversible capacity reaches 1478 mAh·g −1 after 45 cycles, and it is equal to 1035 mAh·g −1 after 350 cycles at a current density of 200 mA·g −1 . Furthermore, the changes after 30, 45, 60, 90, and 120 cycles are investigated. It is found that the electrochemical performance varies with the morphological change of the electrode surface. Correspondingly, the microstructure, cyclic voltammetry curves, and Nyquist plots significantly change as a consequence of cycling. The results of this study provide an understanding of the increased capacity and excellent cyclic performance of a new anodic material for Li‐ion batteries.