Surface-seeding secondary growth for CoO@Co9S8 P-N heterojunction hollow nanocube encapsulated into graphene as superior anode toward lithium ion storage

Heterointerface plays the key role to adjust and enhance the charge carrier transport behavior of composite electrode materials in Li-ion batteries. However, fabricating heterostructures with suitable band gap and exquisitely distributed architectures is still a challenge to realize excellent electrochemical performance. Herein, heterogeneous [email protected]9S8-rGO hollow nanocube is prepared via surface-seeding and secondary growth followed by subsequent sulfuration and carbonization processes. In this smart design of hollow [email protected]9S8-rGO heterointerface architecture, the built-in electric field between CoO and Co9S8 helps to quicken the Li-ions transport in lithiation and delithiation processes. The abundant CoO-Co9S8 heterointerface exposes more active sites and facilitates the infiltration of electrolyte and Li-ion storage. In-situ generated CoO nanosheet could be a bridge between Co9S8 nanocube and graphene which endows the excellent electron transport channel. As expected, the [email protected]9S8-rGO electrode exhibits a remarkable reversible discharge capacity (912 mAh g−1 at 0.1 A g−1), high rate performance (586 mAh g−1at 5 A g−1), and excellent cycling stability (600 mAh g−1 at 1 A g−1 after 500 cycles). This work provides an effective strategy for constructing heterostructure anode to enhance the Li-ion transfer and storage.