Exploring High‐Energy Li‐I(r)on Batteries and Capacitors with Conversion‐Type Fe₃O₄‐rGO as the Negative Electrode

Abstract

We report a microwave‐assisted solvothermal process for the preparation of magnetite (Fe3O4, ca. 5 nm)‐anchored reduced graphene oxide (rGO). It has been examined as a prospective conversion‐type negative electrode for multiple energy storage applications, such as Li‐ion batteries (LIBs) and Li‐ion capacitors (LICs). A LiFePO4/Fe3O4‐rGO cell is constructed and capable of delivering an energy density of approximately 139 Wh kg−1 with a notable cyclability (ca. 76 %) after 500 cycles. Prior to the fabrication of a LIB, the Fe3O4‐rGO is electrochemically pretreated to eliminate the irreversible capacity loss. In addition to the LIB, a high‐energy LIC is also fabricated by using the pre‐lithiated Fe3O4‐rGO composite as the anode and commercial activated carbon as the cathode. This LIC registered a maximum energy density of approximately 114 Wh kg−1 with good cyclability. For both the LIB and LIC, the mass loading between the electrodes was adjusted based on the performance with metallic Li. The improved electrochemical performance of Fe3O4‐rGO over existing materials is a promising development in the quest for novel, fast, low cost, and efficient energy storage systems without compromising the eco‐friendliness

Hollow Porous α-Fe2O3 Nanoparticles as Anode Materials for High-Performance Lithium-Ion Capacitors

“…10,11 It is therefore critical to develop high-rate capability anode materials to resolve the kinetics imbalance issue. 11 There have been developed many anode materials for LICs, including carbon, 12,13 metal oxides, 14,15 and silicon. 16,17 Among them, Fe 2 O 3 , having the advantages of a high theoretical specific capacity of 1007 mAh g −1 , 18 nontoxicity, earth abundance, and low cost, is considered one of the most attractive anode materials for LICs.…”

A Comprehensive Review of Graphene-Based Anode Materials for Lithium-ion Capacitors

“…By integrating with AC, the Fe 3 O 4 -G-based LICs showed a high energy density of 120 Wh kg −1 , an outstanding power density of 45.4 kW kg −1 and an excellent capacity retention of 81.4% after 10,000 cycles. Besides, one-step solvothermal method [105] and microwave-assisted solvothermal process [106] were also adopted to prepare graphene modified Fe 3 O 4 composites and high performances were achieved.…”

“…By integrating w AC, the Fe3O4-G-based LICs showed a high energy density of 120 Wh kg −1 , an outstan ing power density of 45.4 kW kg −1 and an excellent capacity retention of 81.4% af 10,000 cycles. Besides, one-step solvothermal method [105] and microwave-assisted s vothermal process [106] were also adopted to prepare graphene modified Fe3O4 comp sites and high performances were achieved. Graphene incorporated Mn3O4 and MnO composites have also been applied as a ode materials for LICs because of their high capacity, low redox potential and abunda availability [107,108].…”

Biomass‐Derived Carbon Materials as Prospective Electrodes for High‐Energy Lithium‐ and Sodium‐Ion Capacitors

“…In addition, the anode material, conversion-type Fe 3 O 4 @C, was also prepared by hydrothermalt reatment, followed by annealing at 600 8C. [95][96][97][98] Apart from the creation of macropores, NaCl facilitated the enhancement of the degree of graphitization as a graphitic catalyst, which led to ah igh specific capacity of 119mAh g À1 .F urthermore, the devicew ith the EW-NaCl/ Fe 3 O 4 @C configuration at an optimizedr atio of 2:1d emonstrated as pecific capacity of 42 mAh g À1 ,b ased on the mass loading of the cathode. In addition, the hybrid device bestowedg ood cycling stability,w ith capacity retention of 88.3 % after 2000 cycles.T he superior energy density of 124.7 Wh kg À1 from the high power density of 2547 Wkg À1 was mainly attributed to the good surfacea rea,h ighd egree of graphitization, in-situ-doped heteroatoms,a nd porouss tructure of the EW-NaCl ( Figure 6).…”

“…The N 2 ‐adsorption/‐desorption isotherms confirmed the presence of micropores and mesopores, by displaying a hysteresis loop at P / P 0 >0.5. In addition, the anode material, conversion‐type Fe 3 O 4 @C, was also prepared by hydrothermal treatment, followed by annealing at 600 °C . Apart from the creation of macropores, NaCl facilitated the enhancement of the degree of graphitization as a graphitic catalyst, which led to a high specific capacity of 119 mAh g −1 .…”