▎ 摘　　要

We report the synthesis and application of a material composed of Fe3O4 nanoparticles embedded in N-doped graphene sheets (Fe3O4@N-doped graphene) as a negative electrode for Li batteries. We study the influence of N-doped graphene on the storage capacity of Fe3O4 using different electrochemical techniques. The as-prepared Fe3O4 materials presented high-quality crystalline nanostructures. The N-doped graphene sheets improve the conductivity between the Fe3O4 nanoparticles, allowing a faster charge transfer process than that for pure magnetite, as well as the presence of porous particles in the hybrid composite. The Fe3O4@N-doped graphene material show the best Li storage capacity maintaining specific capacity values of 910 mA h g(-1) during 150 cycles performed at 0.05 A g(-1) and 850 mA h g(-1) at 0.1 A g(-1) during the following 50 cycles. The N-doped graphene sheets resist the volume changes that occur during cycling processes in rate capability experiments. We provide a simple and novel method to obtain a material with a higher superficial area and conductivity between particles, allowing great performance as a negative electrode for Li batteries application.