Graphene Aerogel Supported Fe-Co Selenide Nanocubes as Binder-Free Anodes for Lithium-Ion Batteries

Metal selenides as anode materials of lithium-ion batteries (LIBs) has received considerable attention recently. In order to boost the electronic conductivity and alleviate the volume change of electrode materials upon the cycles, a facile strategy is employed in this work, where Prussian blue analogue (PBA) nanocubes are encapsulated into three-dimensional (3D) network of graphene aerogel (GA), followed by a high-temperature selenization treatment to isolate the composite of FeCoSe2@GA. The composite can be directly employed as free-standing anode materials of LIBs. Studies reveal that the FeCoSe2@GA electrode demonstrates an intriguing cycle stability and rate capability with a specific capacity of similar to 500 mAh g(-1) at 100 mA g(-1) after 100 cycles. The outstanding lithium-storage properties can be attributed to the 3D porous feature as well as the strong confinement effect of GA for FeCoSe2 particles, which provides a large number of ion-exchange channels, and prevents the severe agglomeration and large volume expansion of active particles during the charge/discharge process.