Yolk–Shell NiS₂ Nanoparticle‐Embedded Carbon Fibers for Flexible Fiber‐Shaped Sodium Battery

Abstract

Fiber‐shaped rechargeable batteries hold promise as the next‐generation energy storage devices for wearable electronics. However, their application is severely hindered by the difficulty in fabrication of robust fiber‐like electrodes with promising electrochemical performance. Herein, yolk–shell NiS2 nanoparticles embedded in porous carbon fibers (NiS2⊂PCF) are successfully fabricated and developed as high‐performance fiber electrodes for sodium storage. Benefiting from the robust embedded structure, 3D porous and conductive carbon network, and yolk–shell NiS2 nanoparticles, the as‐prepared NiS2⊂PCF fiber electrode achieves a high reversible capacity of about 679 mA h g−1 at 0.1 C, outstanding rate capability (245 mA h g−1 at 10 C), and ultrastable cycle performance with 76% capacity retention over 5000 cycles at 5 C. Notably, a flexible fiber‐shaped sodium battery is assembled, and high reversible capacity is kept at different bending states. This work offers a new electrode‐design paradigm toward novel carbon fiber electrodes embedded with transition metal oxides/sulfides/phosphides for application in flexible energy storage devices.

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 .…”

“…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. [4][5][6][7][8][9][10] 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. An effective approach to combat these issues is to engineer hierarchical composite of nanostructured TMSs with carbonaceous matrices.…”

Surface Engineering for Advanced Aqueous Supercapacitors: A Review

“…Many applications, e. g ., the storage of intermittent energy (solar, wind, etc . ), demand higher power than batteries can deliver . Therefore, considerable attention has been focused on the supercapacitors (SCs) due to their large power density and excellent cycling stability, which makes it more suitable for high‐power applications .…”

“…), demand higher power than batteries can deliver. [9][10][11] Therefore, considerable attention has been focused on the supercapacitors (SCs) due to their large power density and excellent cycling stability, which makes it more suitable for high-power applications. [12][13][14] Aqueous electrolyte based SCs are attractive because of their excellent power output, much longer cycle life, superior safety, low-cost, and environmental friendliness.…”