Double‐Helix Structure in Carrageenan–Metal Hydrogels: A General Approach to Porous Metal Sulfides/Carbon Aerogels with Excellent Sodium‐Ion Storage

Abstract

The metal sulfide-carbon nanocomposite is a new class of anode material for sodium ion batteries, but its development is restricted by its relative poor rate ability and cyclic stability. Herein, we report the use of double-helix structure of carrageenan-metal hydrogels for the synthesis of 3D metal sulfide (M S ) nanostructure/carbon aerogels (CAs) for high-performance sodium-ion storage. The method is unique, and can be used to make multiple M S /CAs (such as FeS/CA, Co S /CA, Ni S /CA, CuS/CA, ZnS/CA, and CdS/CA) with ultra-small nanoparticles and hierarchical porous structure by pyrolyzing the carrageenan-metal hydrogels. The as-prepared FeS/CA exhibits a high reversible capacity and excellent cycling stability (280 mA h at 0.5 A g over 200 cycles) and rate performance (222 mA h at 5 A g ) when used as the anode material for sodium-ion batteries. The work shows the value of biomass-derived metal sulfide-carbon heterostuctures in sodium-ion storage.

Carbon Nitride Aerogels for the Photoredox Conversion of Water

“…[2] In particular,i nc omparison with LD nanostructures,3 Da erogel superstructures would offer ad esirable combination of low densities,h igh inner surface areas and fast mass transport through broad interpenetrated channels to surface,f or heterogeneous applications such as the fields of energy storage and conversion. [3] Thestudy of the self-assembly among these nanoparticles and the development of the 3D aerogel networks with exciting properties have therefore gained continuous attentions.…”

The State and Challenges of Anode Materials Based on Conversion Reactions for Sodium Storage

“…The morphology of the CoS/C nanowires was investigated after cycling, and the pristine structure was preserved after 200 cycles (Figure e). In attempts to improve the kinetics, a variety of sulfides with different nanostructures have been reported as anodes in SIBs, which have displayed good electrochemical performance with respect to reversible capacity and rate capability …”

General and Scalable Fabrication of Core–Shell Metal Sulfides@C Anchored on 3D N‐Doped Foam toward Flexible Sodium Ion Batteries

“…Therefore, a significant demand for advancing SIBs is the exploration and fabrication of appropriate high‐performance anodes. Recently, enormous efforts have been devoted on the synthesis and applications of nanostructured transitional metal sulfides (TMSs) in SIBs because they usually show distinct advantages over their corresponding transition metal oxide counterparts in terms of electronic conductivity and structural stability . Despite these merits, the existing TMSs usually have unsatisfactory long‐term cyclability and rate capability owing to the pronounced sodiation/desodiation strain and inherent low conductivity of the TMSs themselves.…”

“…The conductive coating layer can not only accommodate the large volume changes of TMSs, but also boosts the charge/ions transport. Typically, a large number of hierarchical TMSs‐based composite structures, including ɑ ‐MnS@N, S‐NTC, NiS 2 ⊂PCF, Co 9 S 8 ‐QDs@NC, double‐helix structure FeS/CA, FeS 2 @C nanoboxes, and FeS@C nanospheres, have been prepared, and the enhanced sodium storage performances are delivered. It is worth noting that these composites are usually in powder form and need to be incorporated with extra polymer binders, which will introduce highly undesirable interfaces and thus probably negate the benefits of scrupulously designed architectures .…”