In-situ growth of binder-free hierarchical carbon coated CoSe2 as a high performance lithium ion battery anode

Transition metal selenides have been regarded as promising materials for lithium ion batteries but still face great challenges, including poor rate performance and unsatisfactory cycling stability. Herein, flexible hierarchical carbon coated CoSe₂ electrode was rationally designed and synthesized for LIBs and demonstrates a high capacity of 638.3 mAh/g, very good rate capability, and excellent cycling stability of 100% after 100 cycles. The impressive electrochemical performance is attributed to the binder-free nanostructured electrode architecture and the carbon coating, which not only highly improves the electric conductivity but also alleviates the volumetric expansion/shrinkage during lithiation/delithiation. This work displays a good case for developing high performance lithium ion battery electrodes based on conversion materials.