Journal of Colloid and Interface Science, Vol.588, 346-356, 2021
Engineering zinc ferrite nanoparticles in a hierarchical graphene and carbon nanotube framework for improved lithium-ion storage
This work presents the successful fabrication of a composite made of multi-walled carbon nanotubes and reduced graphene oxide, with immobilized zinc ferrite nanoparticles (ZnFe2O4@CNT/RGO). Functionalized CNT (F-CNT) and few-layered graphene oxide (GO) not only works as a precursor for the hierarchical CNT/RGO skeleton, but also participates in the redox reactions with zinc and ferrous ions to synthesize the intermediate products ZnO@CNT and FeOOH@RGO, respectively. A ZnO@CNT/FeOOH@RGO composite is obtained by through the spontaneous assembly process between the above intermediate species, and the final ZnFe2O4@CNT/RGO composite is fabricated through a simple solidstate reaction. The ZnFe2O4@CNT/RGO composite delivers a reversible capacity of about 1250 mAh.g(-1) after 100 cycles at a low current of 200 mA.g(-1), about 1100 mAh.g(-1) after 300 cycles at a high current of 1000 mA.g(-1). It has been verified that an increase in battery performance can be attributed to the engineered hierarchical CNT/RGO supportive skeleton, the generation of smaller electrochemically active ZnO and Fe2O3 crystals, and pseudocapacitive behavior. The sample design and preparation method in this work are both economical and scalable, allowing further development and use in other applications. (C) 2020 Elsevier Inc. All rights reserved.