Fe3O4-modified FeCl3/graphite intercalation compound confinement architecture for unleashing the high-performance anode potential of lithium-ion batteries.

ABSTRACT

The ferric trichloride (FeCl3)-intercalated graphite intercalation compound (GIC) has high reversible capacity and bulk density, making it a promising anode material for lithium ion batteries. However, its practical application has been limited by the poor cycle performance due to chloride dissolution and shuttling issues. Herein, FeCl3-GIC is used as the precursor material to synthesize a nano-Fe3O4-modified intercalation material by a solvothermal method. The Fe3O4 moiety at the edge of FeCl3-GIC provides a robust chemical anchoring effect on the chlorides. Together with the two-dimensional graphite layer, it forms a confinement space, which effectively immobilizes soluble chlorides. Attributed to the distinctive structural design, the Fe3O4-FeCl3/GIC 25% C electrode offers a high reversible capacity of 691.4 mA h g-1 at 1000 mA g-1 after 400 cycles. At 2000 and 5000 mA g-1, the reversible specific capacity of the Fe3O4-FeCl3/GIC 25% C electrode is 345.6 and 218.3 mA h g-1, respectively. This work presents an innovative method to improve the lifespan of GIC.