Solvothermal‐Induced Self‐Assembly of Fe₂O₃/GS Aerogels for High Li‐Storage and Excellent Stability

Abstract

A novel solvothermal-induced self-assembly approach, using colloid sol as precursor, is developed to construct monolithic 3D metal oxide/GS (graphene sheets) aerogels. During the solvothermal process, graphene oxide (GO) is highly reduced to GS and self-assembles into 3D macroscopic hydrogels, accompanying with in situ transformation of colloid sol to metal oxides. As a proof of concept, Fe2 O3 /GS aerogels are synthesized based on Fe(OH)3 sol, in which GS self-assemble into an interconnected macroporous framework and Fe2 O3 nanocrystals (20-50 nm) uniformly deposit on GS. Benefitting from the integration of macroporous structures, large surface area, high electrical conductivity, and good electrode homogeneity, the hybrid electrode manifests a superior rate capability (930, 660 and 520 mAh g(-1) at 500, 2000 and 4000 mA g(-1), respectively) and excellent prolonged cycling stability at high rates (733 mAh g(-1) during 1000 charge/discharge cycles at 2000 mA g(-1)), demonstrating its great potential for application in high performance lithium ion batteries. The work described here provides a versatile pathway to construct various graphene-based hybrid aerogels.

Hierarchical Structures Based on Two‐Dimensional Nanomaterials for Rechargeable Lithium Batteries

“…Much research has been based on these disordered graphene network structures as backbones for LIBs and has reported on the exploration of novel functionalities by deposition of active materials on various hierarchical structured graphene and its derivatives, such as Fe 3 O 4 @G/ GFs, [36] SnO 2 /GFs, [37] MoS 2 /GFs, [38] G@NiSb/Sb@NFs, [114] Si/GSs, [63,64] Fe 2 O 3 /GAs, [44,45] Fe 2 O 3 nanocubes/N-GAs, [46] Fe 3 O 4 /N-GAs, [47] Fe 3 O 4 /GAs, [48] Fe 3 O 4 nanospheres/GAs, [49] SnO 2 /N-GAs, [50] CoCO 3 and Co 3 O 4 /GAs, [51] CoO/GAs, [52] MnO 2 /GAs [53] MnO 2 /N-GAs, [54] TiO 2 /GAs, [55,56] Spinel-type oxides/GAs, [57] MoS 2 and FeOx/GAs, [58] MoS 2 /Gas. Hierarchical structured graphenebased materials, including GFs, GAs and GSs, present the disordered conductivity network, high specific surface area, highly flexible and large void space, which appear as a promising 3D supporting matrix for electrochemically active materials in LIBs applications.…”

Synthesis of graphene–transition metal oxide hybrid nanoparticles and their application in various fields

“…This aerogel structure exhibits excellent rate capability and outstanding long-term cyclic stability at high current densities. Wang et al have introduced a solvothermal-induced self-assembly approach to construct the monolithic 3D Fe 2 O 3 and GS hybrids, which have excellent prolonged cycling stability [166]. Geng et al have prepared Fe 3 O 4 –rGO hybrids by one-pot solution chemistry which have good adsorption capability of various dyes (rhodamine B, rhodamine 6G, acid blue 92, orange (II), malachite green, and new coccine) [167].…”

Graphene‐Based Electrodes for Lithium Ion Batteries

“…LIB, with its high-energy density, high voltage, and environmental friendliness, is widely considered as one of the most probable candidates for electric vehicle power source [1,2]. As schematically illustrated in Figure 2.1, an LIB typically consists of a positive electrode (cathode), a negative electrode (anode), a porous membrane (allowing lithium ions to travel through) separating the two electrodes, and an electrolyte (playing the role of conducting lithium ions during charge and discharge).…”

“…Recently, Sun and coworkers [1] developed a novel solvothermal-induced self-assembly approach, using colloid sol as precursor, to construct monolithic 3D metal oxide/GS aerogels. Compared with the general hydrothermal treatment, solvothermal treatment can further restrict the coarsening of the resulting nanocrystals, enable a more thorough reduction of GS, and endow the composite a higher electrical conductivity.…”