Hierarchical sandwiched Fe3O4@C/Graphene composite as anode material for lithium-ion batteries

Nanocrystalline Cellulose-Supported Iron Oxide Composite Materials for High-Performance Lithium-Ion Batteries

Nanocrystalline cellulose (NCC) can be converted into carbon materials for the fabrication of lithium-ion batteries (LIBs) as well as serve as a substrate for the incorporation of transition metal oxides (TMOs) to restrain the volume expansion, one of the most significant challenges of TMO-based LIBs. To improve the electrochemical performance and enhance the longer cycling stability of LIBs, a nanocrystalline cellulose-supported iron oxide (Fe2O3) composite (denoted as NCC-Fe2O3) is synthesized and utilized as electrodes in LIBs. The obtained NCC-Fe2O3 electrode exhibited stable cycling performance, better capacity, and high-rate capacity, and delivered a specific discharge capacity of 576.70 mAh g-1 at 100 mA g-1 after 1000 cycles. Moreover, the NCC-Fe2O3 electrode was restored and showed an upward trend of capacity after working at high current densities, indicating the fabricated composite is a promising approach to designing next-generation high-energy density lithium-ion batteries.

Development of Cellulose Nanofiber-SnO2 Supported Nanocomposite as Substrate Materials for High-Performance Lithium-Ion Batteries

The large volumetric expansion of conversion-type anode materials (CTAMs) based on transition-metal oxides is still a big challenge for lithium-ion batteries (LIBs). An obtained nanocomposite was established by tin oxide (SnO₂) nanoparticles embedding in cellulose nanofiber (SnO₂-CNFi), and was developed in our research to take advantage of the tin oxide's high theoretical specific capacity and the cellulose nanofiber support structure to restrain the volume expansion of transition-metal oxides. The nanocomposite utilized as electrodes in lithium-ion batteries not only inhibited volume growth but also contributed to enhancing electrode electrochemical performance, resulting in the good capacity maintainability of the LIBs electrode during the cycling process. The SnO₂-CNFi nanocomposite electrode delivered a specific discharge capacity of 619 mAh g^-1 after 200 working cycles at the current rate of 100 mA g^-1. Moreover, the coulombic efficiency remained above 99% after 200 cycles showing the good stability of the electrode, and promising potential for commercial activity of nanocomposites electrode.

Facile synthesis of a rod-like porous carbon framework confined magnetite nanoparticle composite for superior lithium-ion storage

This work demonstrates a streamlined method to engineer a rod-like porous carbon framework (RPC) confined magnetite nanoparticles composite (Fe₃O₄/RPC) starting from metallic iron and gallic acid (GA) solution. First, a mild redox reaction was triggered between Fe and GA to prepare a rod-shaped metal-organic framework (MOF) ferric gallate sample (Fe-GA). Then, the Fe-GA sample was calcinated to obtain a prototypic RPC supported metal iron nanoparticle intermediate sample (Fe/RPC). Finally, the Fe₃O₄/RPC composite was synthesized after a simple hydrothermal reaction. The Fe₃O₄/RPC composite exhibited competitive electrochemical behaviors, which has a high gravimetric capacity of 1140 mAh·g^-1 at a high charge and discharge current of 1000 mA·g^-1 after 300 cycles. The engineered RPC supportive matrix not only offers adequate voids to buffer the volume expansion from inside well-dispersed Fe₃O₄ nanoparticles, but also facilitates both the ionic and electronic transport during the electrochemical reactions. The overall material synthesis involves of no hazardous or expensive chemicals, which can be regarded to be a scalable and green approach. The obtained samples have a good potential to be further developed for wider applications.