In Situ Synthesis and Unprecedented Electrochemical Performance of Double Carbon Coated Cross-Linked CoO.

Improving the structural stability and the electron/ion diffusion rate across whole electrode particles is crucial for transition metal oxides as next-generation anodic materials in lithium-ion batteries. Herein, we report a novel structure of double carbon-coated CoO cross-linked composite, where the CoO nanoparticle is in situ covered by nitrogen-doped carbon and further connected by carbon nanotubes (CoO NP@NC@CNTs). This double carbon-coated CoO NP@NC@CNTs framework not only endows a porous structure that can effectively accommodate the volume changes of CoO but also provides multidimensional pathways for electronic/ionic diffusion in and among the CoO NPs. Electrochemical kinetics investigation reveals a decreased energy barrier for electron/ion transport in the CoO NP@NC@CNTs, compared with the single carbon-coated CoO NP@NC. As expected, the CoO NP@NC@CNT electrode exhibits unprecedented lithium storage performance, with a high reversible capacity of 1017 mA h g after 500 cycles at 1 A g, and a very good capacity retention of 75%, even after 5000 cycles at 15 A g. The lithiation/delithiation process of CoO NP@NC@CNTs is dominated by the pseudocapacitive behavior, resulting in excellent rate performance and durable cycle stability.