Metal-organic framework-derived nitrogen-doped three-dimensional porous carbon loaded CoTe2 nanoparticles as anodes for high energy lithium-ion capacitors

Abstract

In this work, we propose a strategy to use MOF-derived carbonaceous materials to modify Co-based nanoparticle anodes, so as to achieve heteroatom doping, structure and electronic properties of composite electrode materials in one step. In more detail, this paper uses the cobalt-based metal-organic framework (ZIF-67) as the precursor matrix to synthesize Co, Co3O4 and CoTe2 nano-particles embedded in carbon nanocubes composite electrode materials through carbonization, oxidation and tellurization reactions in sequence. As a result, electrochemical experiments and test results show that the reversibility of Li+ storage of the half-cell CoTe2@NC composite is significantly enhanced, and it has a higher rate capacity, ultra-fast charging capability and long cycle stable life. On this basis, we built the lithium-ion capacitor (CoTe2@NC//HPC) for the first time, which achieves a high energy density of 144.5 Wh kg−1 while maintaining a high-power density of 10 kW kg−1. Finally, the device exhibits excellent electrochemical structural stability, and can still maintain an original capacity of 90.95% after 1000 charging-discharging cycles. Thus, the rational design and development of partially coated nanoparticle structures derived from MOF is of great significance for improving the energy density and power density of advanced energy storage devices.