High-performance flexible and self-healable quasi-solid-state zinc-ion hybrid supercapacitor based on borax-crosslinked polyvinyl alcohol/nanocellulose hydrogel electrolyte

Abstract

The quasi-solid-state zinc-ion hybrid supercapacitor based on borax-crosslinked polyvinyl alcohol/nanocellulose hydrogel electrolyte displays not only great electrochemical performances but also high flexibility and self-healing ability.

Self‐healing Polyol/Borax Hydrogels: Fabrications, Properties and Applications

“…rapid erosion at highly acidic/alkaline pHs but stable at 3 > pH > 10 [42][43][44] PVA/sodium alginate containment of hazardous chemicals alginate improved the stretchability [46] GG as flocculant in water treatment [47,48] GG/glycerol -antifreeze, injectable, water stable, flexible, stretchable [49] HPG/glycerol -glycerol at < 1 wt % acts as stiffening agent & at > 1wt % as plasticizer [50] FG water-retaining agent in agriculture [51] PVA/SF sensing platforms SF boost stretchability (> 5000 %), healability, adhesivity & thermal stability [52] Functionalized polyol/B hydrogels PVA-g-PAA smart electrochemical capacitors PAA improved salt tolerance & flexibility [53] JG-g-PAAm removal of Brilliant Blue R dye from water easy regeneration of hydrogel-based adsorbent [54] PAH-g-Glu showing viscoelastic behavior at pH � 6; gradual degradation at pH > 8 [55] PEG-diacrylate/DTT as glucose-sensitive sacrificial material for fabrication of vascularized constructs one-pot polymerization and hydrogel formation via borate-catalyzed click reaction [56,57] Nanocomposite borax-based hydrogels PVA/CNC or CNF CNC or CNF boost mechanical strength and viscoelasticity [58][59][60] PVA/CNF supercapacitor Zn(II) endow excellent ionic conductivity [61] PVA/MFC MFC improve mechanical strength and viscoelasticity [62] PVA/Ag/TA/CNC strain sensor; circuit repairing agent; electronic skin, and touch screen pens.…”

“…[100] Moreover, addition of other ingredients to the boraxbased nanocomposite hydrogels have been evaluated for the fabrication of hybrid materials. For instance, addition of metal cations (such as Zn 2 + ) [61] can create supercapacitors or addition of polyphenols [63][64][65] can enhance the adhesivity and endow antioxidant property to the hydrogel. Especially, addition of metals such as Fe(III) and Al(III) to the hydrogels containing polyphenols increase the adhesivity dramatically [69] due to the complexation of these metals with phenolic groups.…”

“…Zinc-salt-doped PVA/CNF/B hydrogels with high mechanical stability and excellent ionic conductivity were developed as an electrolyte. [61] The electrolyte hydrogel was prepared by immersing PVA/CNF/B hydrogel in the ZnSO 4 aqueous solution. Hydrogel showed almost complete healing efficiency so that 20 s healing recovered original strain and stress values of the hydrogel.…”

“…(a) Frequency dependence of G' and G'' for PVA/B hydrogels and the effect of CNF and CNC on the viscoelasticity properties (The length of CNF I, CNC I and CNC II were around 732, 149 and 46 nm, respectively) [59] (Copyright 2014 Elsevier). (b) The dependence of the values of G', G'', G* (complex modulus) and η* (complex viscosity) in PVA/CNF/B hydrogel on the frequency at γ � 1% [61] (Copyright 2019 The Royal Society of Chemistry). (c, d) Self-healing demonstration of PVA/MFC/B hydrogels and recovery of viscoelastic properties (Copyright 2017 American Chemical Society).…”

Hollow Mesoporous Carbon Spheres for High Performance Symmetrical and Aqueous Zinc-Ion Hybrid Supercapacitor

“…Aqueous zinc-ion hybrid supercapacitors (ZHSs) have recently emerged as promising energy storage devices, due to the intrinsic advantages of the zinc element, such as a high capacity of 820 mAh/g in theory, low redox potential of −0.76 V vs. a standard hydrogen electrode (Ma et al, 2018;Chen et al, 2019a;Yu et al, 2019). For instance, Ma et al (2019) have developed a ZHS with a γ-phase MnO 2 nanorods as a cathode and activated carbon particles as an anode, which demonstrated a high specific capacity of 54.1 mAh/g (34.8 Wh/kg) at 0.1 A/g current density.…”