Co3O4 nanoparticles embedded in nitrogen-doped graphitic carbon fibers as free-standing electrode for promotion of lithium ion storage with capacitive contribution

Here, we wrap the Co3O4 nanoparticles into nitrogen-doped graphitic carbon nanofibers (Co3O4@NGFs) as a self-standing electrode for lithium-ion batteries. In this structure, graphitic carbon acts as composite framework that enhances the conductivity, accommodates the volume expansion and increases the contact with the electrolyte. Meanwhile, the porosity of the Co3O4@NGFs not only facilitates the rapid electron transfer, but also exposes more active sites for lithium storage. Furthermore, the surface-controlled capacitive processes and diffusion-controlled processes have also been proven to contribute to the enhanced performances.