Construction of Sandwich‐Like r‐Fe₃O₄/rGO@CN Anode Materials as Conductive Agent‐Free Anode for Lithium‐Ion Batteries

Abstract

Fe 3 O 4 is a prospective anode material but faces challenges to develop high-performance electrodes for lithium-ion battery. In this paper, Fe 3 O 4 nanorods wrapped with reduced graphene oxide (rGO) as the conducting matrix and an amorphous nitrogen-doped carbon (CN) as the protective coating were prepared using the hydrothermal method and freeze-drying process. The obtained Fe 3 O 4 nanorods are uniformly dispersed on the rGO nanosheet. The addition of rGO improves the electrical conductivity of the composite, while the amorphous carbon layer mitigates the volume expansion effect of Fe 3 O 4 nanorods. Moreover, the insitu nitrogen doping accelerates the wetting effect of the electrolyte as well as reduces the diffusion and transfer resistance. Therefore, the obtained r-Fe 3 O 4 /rGO@CN composite as conductive agent-free anode exhibits outstanding performance and cycling stability at suitable nitrogen-doped carbon coverage. The capacity could be maintained at 1020.7 mA h g À 1 after 100 cycles at a current density of 0.5 A g À 1 . In addition, the capacity fading rate of per cycle is only 0.08% at a high current density of 2 A g À 1 . Our findings suggest that the prepared r-Fe 3 O 4 /rGO@CN composite is a prospective candidate for utilization as an anode material in lithium-ion batteries.

Graphene–Encapsulated Si@C with Dual Carbon Layer Structure as High‐Performance Anode Materials for Lithium–Ion Batteries

“…The fitting values of R ct for Si@C@rGO‐1, Si@C@rGO‐2, and Si@C@rGO‐3 are 79.83 Ω, 104.71 Ω, and 129.55 Ω, respectively, lower than the fitted values of R ct for Si@C (204.47 Ω) and Si (321.01 Ω), which indicates that the introduction of rGO is beneficial to improve the ion and electron transfer rate of the electrode material. The slope of the straight line in the low frequency region reveals the diffusion of ions in the electrode material and is expressed in terms of the Warburg factor, which can be defined by the slope of the linear fitting curve of Z' and ω − 1/2 : [32] $$$\vcenter{\openup.5em\halign{$\displaystyle{#}$\cr Z{{\char39}} ={R}_{ct}+{R}_{s}+\sigma {\omega }^{-1/2}\hfill\cr}}$$$ …”

Upcycling of spent graphite and iron housing from waste lithium-ion batteries for fabricating cost-effective high-capacity anodes

“…58 The CV graphs mostly overlapped after the 1st cycle, suggesting that the SEI prevents immediate contact of the Fe 3 O 4 with the electrolyte and maintains the unity of the anode, affording superior cyclability. 59 Before cycling, the samples were subjected to electrochemical impedance spectroscopy (EIS) analysis (Fig. 4b).…”

NiCo Nanoparticles Encapsulated in Nitrogen-Doped Carbon Tubes as Anode Materials for High-Performance Lithium-Ion Batteries

“…6−8 Nonetheless, the limitations of carbon-based materials, including their poor rate performance and low theoretical capacity, hinder further advancements in LIBs. 9,2 Thus, exploring new carbon-based anode materials with higher capacity and multicycling performance is essential. 2,10,11 Various promising anode candidates with high theoretical capacities have been extensively investigated to replace graphite, such as transition metal oxides (TMOs), sulfides, carbides, phosphides, and nitrides (e.g., MoO 2 , Ni 2 S 3 , SiC, Co x P, and g-C 3 N 4 ).…”

“…Li-ion batteries (LIBs) are essential components that play a crucial role in the electric vehicle and consumer electronics markets owing to their long cycles, high energy density, and no memory effect. As applications for portable electronic devices continue to expand, market expectations for the performance of LIBs are increasing. , As a key component of LIBs, the anode material significantly influences their performance. − Graphite is the preferred commercial anode material for LIBs as it offers several advantages, including high electrical conductivity, low volume expansion, abundant natural resources, and low cost. − Nonetheless, the limitations of carbon-based materials, including their poor rate performance and low theoretical capacity, hinder further advancements in LIBs. , Thus, exploring new carbon-based anode materials with higher capacity and multicycling performance is essential. ,, …”