Self-Sacrificing Template of the POMs-Based Composite for the High-Performance Organic–Inorganic Hybrid Cathode of Lithium-Ion Batteries

Abstract

The high theoretical capacity of vanadium oxides makes them promising cathode candidates for the rechargeable lithium-ion batteries (LIBs). Nevertheless, the relatively poor electrical conductivity and capacity retention hinder the practical application and have to be overcome urgently for the increasing demand for storage technologies. Herein, a new BRG system composed of bimetallic oxide/rhodamine B (RB)/reduced graphene oxide (RGO) was prepared through the facile self-sacrificing template of the precursor polyoxometalate (POM) composites POMs/RB/RGO (PRG). RB not only acts as a cationic mediator to facilitate the loading of POMs on graphene for conversion to oxides but also promotes the formation of uniform nanorods on the RGO. The prepared composite FeV3O8-RB/RGO-1 as the cathode exhibits superior cycling stability (specific capacity of 225 mA h g–1 at 100 mA g–1) and elastic rate capabilities for LIBs. What is more, the new PRG precursor provides versatile possibilities for the design of oxide composites from the self-sacrificing template of POMs-based composites with abundant architectural designs and compositions for the energy storage system.

Electron Storage Performance of Hybrid Materials Comprising Polyoxometalates and Carbon Nanohorns as Cathode‐Active Materials

“…In particular, the maximum discharge capacity during the second discharge process at a current density of 1000 mAh/g was larger than that of the POM/CHNox hybrid at a current density of 200 mAh/g during the second discharge. Generally, battery capacity decreases with an increase in current density [29,30] . This result indicates that unlike POM materials hybridized with SWCNT and RGO, the POM/CNHox hybrid materials can maintain a high battery capacity even at high current densities and have the potential for achieving improved charging/discharging rates.…”

“…Generally, battery capacity decreases with an increase in current density. [29,30] This result indicates that unlike POM materials hybridized with SWCNT and RGO, the POM/CNHox hybrid materials can maintain a high battery capacity even at high current densities and have the potential for achieving improved charging/ discharging rates. This is because CNHox has a higher specific surface area when compared with other nanocarbons (CNHox: 1300-1400 m 2 /g, [28] CNHag: 400 m 2 /g, [28] RGO: 450 m 2 /g, [31] and SWCNT: 400-1000 m 2 /g [32] )) and easier Li + ion diffusion was induced by aperture treatment at the tip of CNHox.…”

Recent Advances in Confining Polyoxometalates and the Applications

“…[ 89 ] Lan group anchored Rhodamine B (abbreviated as RB)‐modified POMs ([Fe 3 V 18 O 42 (H 2 O) 12 (VO 4 )]·24H 2 O) onto reduced graphene oxide (RGO) substrate through electrostatic interaction to solve the solubility, conductivity, and aggregation problems of POMs in the organic electrolyte. [ 90 ] The positively charged RB molecule in the POMs/RB/RGO composites acted as a bridge to combine POM with RGO. In addition, the aromatic ring of RB endowed a strong π–π interaction with the RGO substrate, which not only effectively improved the loading amounts of active components, but also ensured the rapid electron transfer over the entire composites.…”

Magnetoelectric synergy strategy for superior iron disulfide anode

“…More significantly, the benign interface compatibility is convenient for deposition/ stripping of Na + , and so a closer approach to the crystal state for the heterostructure is necessary to guarantee the dendrite-free case. [37][38][39][40] Additionally, marginalization of active sites, such as through exposed edge sites and dangling sites, is detrimental for both the insertion and conversion of Na + over FeS 2 , in which the construction of multiboundary edge and S vacancies generate rich active sites that are favorable for lowering the surface-free energy barrier for Na + storage. [41][42][43][44] Moreover, a Lorentz forceassisted MHD effect over the FeS 2 complex can promote convective Na + transfer within the electrolyte, to give a uniform Na + flux, which is beneficial for homogeneous deposition of Na + , and thus prevents the growth of Na dendrites and improves the stability of the SEI layer.…”