Hierarchical Co3Se4 Nanoparticles Encapsulated in a Nitrogen-Doped Carbon Framework Intertwined with Carbon Nanotubes as Anode of Li-Ion Batteries

Transition metal selenides (TMSes) are regarded as ideal anode materials for lithium-ion batteries (LIBs) due to their high theoretical capacity, but some defects, such as volume expansion and poor conductivity, still need to be overcome. The design of hierarchical structural materials with compositional and structural complexity is extremely attractive in the field of energy conversion. Herein, a core-shell hierarchical polyhedral Co3Se4 with N-doped and carbon nanotubes intertwined (N-Co3Se4@C-CNTs) is synthesized using a facile metal-organic framework (MOFs) self-templating strategy and selenization treatment. The Co3Se4 nanoparticles can be confined in the multilocular and hollow carbon framework intertwined with CNTs. Benefiting from the unique structure and composition superiority, the synthesized N-Co3Se4@C-CNTs exhibit excellent Li storage performance. Specifically, they present a high reversible capacity of 820 mAh g(-1) at 0.1 A g(-1) after 100 cycles and outstanding cycling stability (558 mAh g(-1) at 2 A g(-1) after 1000 cycles). In addition, a LiCoO2 parallel to N-Co3Se4@C-CNT full cell is successfully constructed to show its potential for practical application. The reaction kinetics and Li storage mechanisms of the N-Co3Se4@C-CNT electrode are investigated to explain the impressive electrochemical performance. This work reveals the great application potential of the N-Co3Se4@C-CNT electrode in constructing advanced LIBs.

Automated summary

Transition metal selenides, specifically N-Co3Se4@C-CNTs, with a hierarchical polyhedral structure show excellent lithium storage performance in lithium-ion batteries. The unique design and composition allow for high reversible capacity and outstanding cycling stability, demonstrating great potential for advanced LIBs.