Biaxial Stretchability in High‐Performance, All‐Solid‐State Supercapacitor with a Double‐Layer Anode and a Faradic Cathode Based on Graphitic‐2200 Knitted Carbon Fiber

Abstract

Large reversible biaxial (xy) stretching in energy storage devices is now an urgent requirement for the field of stretchable electronics to enable reliability in practical applications. Here, a fascinating stretching machine is designed and used for xy‐stretching of a high‐performance supercapacitor device without performance degradation. A trimetallic metal organic framework (MOF)‐derived ternary metal oxide on graphitic‐2200 knitted carbon fiber (MOF‐ZNCO@g‐KCF), activated carbon loaded onto drilled knitted carbon fiber (AC@g‐KCF‐d), and a poly‐vinyl alcohol, poly‐ethylene oxide, and potassium hydroxide (PVA/PEO/KOH) based hydrogel polymer film are used as a faradic cathode, a double layer anode, and an electrolyte, respectively, to integrate the biaxially stretchable asymmetric supercapacitor (BSASC) device. The fabricated MOF‐ZNCO@g‐KCF//AC@g‐KCF‐d BSASC maintains an outstanding performance consistency at different xy‐stretched conditions, even after repeated deformations. Notably, after 10 000 galvanostatic charge–discharge cycles, the BSASC in the xy‐biaxial stretched condition is retained at 93.7%, and after 100 successive stretch–relax cycles for the same stretching dimension it still retains a 92.48% capacity, demonstrating excellent mechanical and electrochemical stability. The exceptional performance consistency in the xy‐stretched position, demonstrates that the BSASC is one of the best performers among the stretchable supercapacitors reported to date.

Hierarchical3Dmicro‐nanostructures based on in situ deposited bimetallic metal‐organic structures on carbon fabric for supercapacitor applications

“…Figure 8A shows a HRXPS profile of Ni 2p fitted out with two spin‐orbit doublets. For the NZMF sample, band energies of 856.24 and 873.69 eV were allotted to Ni 2p 3/2 and Ni 2p 1/2 , correspondingly, signifying a signal from Ni 2+ 31,32 . Also, the strong signal of Ni 2+ may be due to the formation of oxygen‐rich nickel oxide in the atmosphere.…”

Recent Development of Flexible and Stretchable Supercapacitors Using Transition Metal Compounds as Electrode Materials

“…Stretchable 1D fiber SCs possess twisting, parallel, coaxial, or helix structures. [ 58,60,69–72 ] Stretchable 2D planar electrodes or SCs can be prepared by depositing active materials on a prestrained stretchable substrate like elastomers or stainless‐steel mesh to obtain wavy structured electrodes. [ 73–77 ] Stretchable 3D structured SCs can be achieved by using kirigami/origami methods, [ 78–80 ] 3D printing technology, [ 65,81 ] or 3D textiles.…”

“…The assembled NiCo 2 S 4 /CoS 2 //AC ASC demonstrated an energy density of 60.2 Wh kg −1 at a power density of 800 W kg −1 , displayed tensile recovery (≤40% elongation) and retained 76% of its capacity after 1000 cycles at 30% strain. Furthermore, Kim's group [ 71 ] fabricated a biaxially stretchable SC using a xy ‐stretchable graphitic‐2200 knitted carbon fiber (g‐KCF) substrate. The stress–strain plots (Figure 8i) revealed that g‐KCF resisted high stress of 0.9 MPa.…”

A Review of Electrospun Carbon Nanofiber-Based Negative Electrode Materials for Supercapacitors

“…However, CC by itself has an extremely low capacitance due to its small surface area (<10 m 2 g −1 ) and larger size compared to nanostructured materials. Recently, the activation of CC to increase its surface area has been considered a prominent strategy for achieving anode materials with a high capacitance [62]. Increasing the surface area of a material is a prime strategy since the surface is involved in ion adsorption and desorption at the electrode-electrolyte interface of an EDLC [63,64].…”