Stretchable and High-Performance Supercapacitors with Crumpled Graphene Papers

Abstract

Fabrication of unconventional energy storage devices with high stretchability and performance is challenging, but critical to practical operations of fully power-independent stretchable electronics. While supercapacitors represent a promising candidate for unconventional energy-storage devices, existing stretchable supercapacitors are limited by their low stretchability, complicated fabrication process, and high cost. Here, we report a simple and low-cost method to fabricate extremely stretchable and high-performance electrodes for supercapacitors based on new crumpled-graphene papers. Electrolyte-mediated-graphene paper bonded on a compliant substrate can be crumpled into self-organized patterns by harnessing mechanical instabilities in the graphene paper. As the substrate is stretched, the crumpled patterns unfold, maintaining high reliability of the graphene paper under multiple cycles of large deformation. Supercapacitor electrodes based on the crumpled graphene papers exhibit a unique combination of high stretchability (e.g., linear strain ~300%, areal strain ~800%), high electrochemical performance (e.g., specific capacitance ~196 F g−1), and high reliability (e.g., over 1000 stretch/relax cycles). An all-solid-state supercapacitor capable of large deformation is further fabricated to demonstrate practical applications of the crumpled-graphene-paper electrodes. Our method and design open a wide range of opportunities for manufacturing future energy-storage devices with desired deformability together with high performance.

N-doped crumpled graphene: bottom-up synthesis and its superior oxygen reduction performance

“…Thus the devices made by CrG are significantly less dependent on the electrode mass loading, showing high potential of crumpled form in preventing graphene restacking and maintaining high accessible surface area, which is especially appealing for real applications of energy conversion and storage [18][19][20][21][22][23][24][25][26][27][28][29][30][31]. For instance, CrG induced by metal oxide template barely changed its capacitance as current density increasing from 0.5 to 100 A g −1 , because the crumpled form can efficiently provide plentiful, stable interfacial contacts and low-electrical-resistance pathways even under extremely high compressive strength [9,15,32,33].…”

Recent advances and challenges of stretchable supercapacitors based on carbon materials

“…Furthermore, the wavy-shaped PANI/graphene electrodes were also used to fabricate the SSC [136], which showed a maximum specific capacitance of 261 F g −1 and an energy density of 23.2 W h kg −1 at a power density of 399 W kg −1 for a 0.8 V voltage window at a maximum strain of 30%. A novel road is reported for demonstrating practical applications of the crumpled-graphene-paper electrodes [143]. The nano-porous structure graphene paper is attached on an elastomer film that has been uniaxially or biaxially stretched into patterns, so that the graphene paper is folded and crumpled.…”

Carbon Nanofiber versus Graphene‐Based Stretchable Capacitive Touch Sensors for Artificial Electronic Skin

“…An integrated electronic platform, containing stretchable touch sensors along with other elements such as microscale light‐emitting diodes (LEDs), transistors, resistors, and antennae, that can conform to epidermal topology and equally function in elongated state, may have many implications in biomedical electronics and in humanoid and soft robotics 2, 3, 4, 5. Other emerging applications of such devices are unconventional energy storage technologies, such as mechanically deformable supercapacitors,6, 7 and safety or structural health monitoring in civil engineering 8…”

“…GnPs are in fact made up of many‐layers graphene and are sometimes referred to as graphite‐like nanoflakes 39. Due to their thin sheet‐like morphology, GnPs can even be molded or crumpled in situ within the embedding polymer, in such a way that under elongation they can display supercapacitance 6. Although very promising flexible capacitors have been developed with graphene or GnPs,40, 41 novel and simple GnP‐based capacitive devices that can function efficiently under 100% elongation and even more will be very beneficial for soft robotics human interactions.…”