High‐Performance Ferrocene‐Metal Complexes for Lithium Storage

Ferrocene is characterized by its potential applications in chemical energy storage owing to the unique structure, redox activity, and chemical stability. Tin (Sn) and bismuth (Bi) are promising anode materials for lithium‐ion batteries (LIBs) due to their high capacity. In this work, we report the rational design and synthesis of two novel ferrocene–functionalized complex architectures by choosing Sn 2+ and Bi 3+ as the metal centers through a simple solvent thermal method for boosting the performance of lithium storage. Specifically, the Sn complex ( SnFc ) electrode demonstrates a high reversible capacity of 749 mAh g −1 at 0.2 A g −1 after 100 cycles. Comparatively, the Bi complex ( BiFc ) electrode demonstrates a reversible capacity of 553 mAh g −1 at 0.2 A g −1 after 200 cycles. While the full battery, coupled with a commercial NCM 523 cathode of BiFc anode, demonstrates better discharge‐charge performance compared to that of the SnFc anode. Both the metal centers and the iron in the ligand actively participate in the redox reactions during the lithiation/delithiation processes, and their synergistic interaction contributes to the superior performance of the material compared to single‐metal complexes. This work may shed light on the pursue of high‐performance ferrocene‐based complex anodes of LIBs and elucidate the lithium storage mechanism.