Rational design of nano-Fe3O4encapsulated in 3D honeycomb biochar for enhanced lithium storage performance.

Developing green materials applied in lithium-ion batteries is of significant importance for the present-day society. Herein, a feasible strategy to construct Fe3O4nanoparticles (NPs) embedded in three-dimensional (3D) honeycomb biochar derived from pleurotus eryngii was proposed. The obtained material consists of Fe3O4NPs (35-85 nm) encapsulated in 3D honeycomb biochar possesses a high specific capacity of 723 mAh g-1at 1.5 A g-1after 1000 cycles. The effectively enhanced cycling life of Fe3O4@C nanocomposites can be ascribed to the small Fe3O4NPs provide lower degree of cracking and high specific capacity, while the honeycomb biochar function like a cage to inhibit huge volume change of Fe3O4NPs during the charge-discharge process.