A Highly Stretchable Supercapacitor Using Laser‐Induced Graphene Electrodes onto Elastomeric Substrate

Abstract

(polyimide and polyetherimide) [ 20 ] that cannot provide the suitable mechanical properties required for stretchable energystorage devices.Herein we report a simple method to transfer the LIG porous layer obtained onto polyimide sheet to a transparent and elastomeric substrate such as PDMS (polydimethylsiloxane). Morphology and chemical-physical properties of the obtained material were deeply characterized by electron microscopy investigation, contact angle measurements and vibrational spectroscopy analysis. The as-fabricated electrodes were assembled into symmetric electrical double-layer supercapacitors and, thanks to the intrinsic mechanical properties of PDMS, the retention of energy-storage performance under bending and stretching conditions was demonstrated.The fabrication process of the LIG/PDMS electrodes is described in the experimental section (see also Supporting Information) and schematically represented in Figure 1 a-d: porous LIG pattern was obtained by a direct writing of polyimide sheet using a nanosecond CO 2 laser (a); afterward the PDMS was poured onto the written sample and the air was evacuated by a vacuum step in order to allow the full infi ltration of PDMS into the 3D network (b); after a thermal curing at 80 °C for 1 h the LIG/PDMS slide was manually peeled off from the polyimide sheet (c,d). The resulting composite material take advantage of the unique mechanical properties typical of elastomers (Figure 1 e) and of the good electrical conductivity and high surface area intrinsically present in LIG structures. Figure 1 f,g show the transparency of a logo pattern written on polyimide foil and then transferred onto PDMS slice respectively. The preservation of the electric conduction was tested by using LIG/PDMS composite to close a circuit (powering a green LED) as shown in Figure 1 h and by electrical measurements. Current-voltage characteristics shown in Figure S1 (Supporting Information) were recorded on the LIG/PDMS sample subjected to stretching in the range 0%-50%, confi rming the good maintenance of electrical properties.FESEM characterization was used to assess the morphology of the LIG sample before and after transfer onto PDMS substrate. Figure 2 a,b show the characteristic 3D foam-like structure of the laser-written LIG sample, which is composed of multilayer graphene walls. The holey foam-like structure, which is a result of the emission of gases during the irradiation process, [ 20,21 ] is actually well suited for both infi ltration with PDMS and impregnation with the electrolyte for supercapacitor application. Figure 2 c presents a cross-sectional view of a LIG sample after it is successfully transferred onto a PDMS substrate through the cast-and-peel process. Thanks to the effective infi ltration of PDMS, the LIG shows good adhesion to the underlying fl exible substrate. Moreover, as shown in Figure 2 d-f, a 3D structure of interconnected multilayer The fi eld of wearable electronics has been evolving very rapidly in the last few years due to the increasing demand for fl exi...

Flexible, Stretchable, and Transparent Planar Microsupercapacitors Based on 3D Porous Laser‐Induced Graphene

“…[33][34][35][36] Meanwhile, we take advantages of the high stretchability and elasticity of silicone rubber, in favor of the practical application of flexibility of MSCs. Compared with the MSCs based on LIG on the polydimethylsiloxane (PDMS) substrate reported in literature, [37] our MSCs present greatly better capacitive and electrochemical properties, and higher stretchability of the devices due to the lower elastic modulus of silicone. Its specific capacity reaches 790 µF cm −2 , which can match with the common MSCs fabricated with graphene synthesized by chemical reaction.…”

“…Therefore, the devices can be stretched to the length of 400% (Figure 4c and Video S1 (Supporting Information)) and are more flexible than the stretchable supercapacitors onto PDMS (Table S1, Supporting Information). [37] The LIG/silicone rubber layer structure at different strains were observed and the layer becomes thinner ( Figure S5 cannot be ignored that porous space was largely occupied by silicone rubber, leading to smaller electrochemical performance than the LIG on PI. The electrodes at strain states exhibit high resistance, so the capacitance obviously decreases as the tension increases (Table S2, Supporting Information).…”

“…Furthermore, the MSCs can exhibit an area special capacitance up to about 790 µF cm −2 at the discharge current of 50 µA cm −2 , which is higher than the value of supercapacitors on PDMS including LIG and reduced graphene oxide (Table S1, Supporting Information). [37,48] Repeated galvanostatic cycling of the LIG-N-PEDOT MSC was performed at 200 µA cm −2 . The behavior of the full devices is presented in Figure 3d.…”

A Highly Stretchable Microsupercapacitor Using Laser‐Induced Graphene/NiO/Co3O4 Electrodes on a Biodegradable Waterborne Polyurethane Substrate

“…Briefly, by covering the PI film with a layer of gelatin-mediated ink containing Ni/Co ions, NiO/Co 3 O 4 /LIG patterns could be in situ synthesized during laser writing. [28] The transparency of a logo pattern induced on the PI film and then transferred to the WPU substrate is shown in Figure 1b, which also indicates the convenience and universality of our stretchable MSC fabrication method. [29] The surface morphology evolution of the electrodes during the peeling process are shown in the inset of Figure 1a, suggesting that NiO/Co 3 O 4 /LIG is fully transferred to WPU without much retention.…”

“…[27][28][29][30] For example, Lamberti et al demonstrated PDMS based stretchable MSCs with an areal capacitance of 650 µF cm −2 that showed an 84% capacitance retention after 1000 cycles of stretching. [27][28][29][30] For example, Lamberti et al demonstrated PDMS based stretchable MSCs with an areal capacitance of 650 µF cm −2 that showed an 84% capacitance retention after 1000 cycles of stretching.…”