Porous CaFe₂O₄ as a promising lithium ion battery anode: a trade-off between high capacity and long-term stability

Metal oxides are considered as attractive candidates as anode materials for lithium ion batteries (LIBs) due to their high capacities compared to commercialized graphite. However, fast capacity fading, which is caused by inherent large volume expansions and agglomeration of active particles upon cycling, is a great challenge. Herein, we propose the design of porous CaFe2O4 electrode material to address the above issue. Compared to pristine iron oxides, CaFe2O4 exhibits a distinct trade-off in terms of high capacity and long-term stability, which is beneficial to the potential practical applications. Such a trade-off effect is attributed to the synergistic effect between the porous structure and the in situ formed CaO nanograins during charging/discharging processes. This work provides an effective strategy in achieving anode materials with high capacity and long-term stability for next-generation LIBs.