Wearable electronics are now moving towards transparent and stretchable promoting the synergetic development in transparent flexible energy storage devices. Typical supercapacitor electrodes suffer the stretchability limitation due to the material rigid and brittleness. Transparent stretchable electrodes are critical elements in the investigation of transparent and stretchable supercapacitors. Generally, the most widely used materials for TSEs are carbon nanotubes (CNTs), graphene, metal-nanowires, and metallic meshes. The homogeneous and designable metallic mesh attracted more attentions due to their high conductivity, thermal and air stability, easy management of optoelectrical properties and reproducibility. However, typical metallic mesh electrodes are usually substrate-supported with synthetic polymers, like polyethylene glycol terephthalate (PET), polyethylene naphthalate (PEN). The inherent properties of the substrate, such as greater thickness, lower optical transmittance, poor stretchability have appeared pronounced shortcomings. Here, we proposed a freestanding metal-mesh with serpentiform grid arrangement for its high transparency, super-flexibility and stretchability, and ultrathin thickness, which can be employed as high performance transparent stretchable supercapacitor current collectors. The solid supercapacitor assembled by the proposed stretchable and transparent electrode reveals a high transparency of 82% at the wavelength of 550 nm and large capacitance of 1.1 mF/cm2. The superior device indicates an outstanding capacity retention up to 88% under 90% strain and sustained its electrochemical performance upto 67% even after 120% strain that meet the requirement in daily life condition. The serpentiform structured metallic mesh can be a strong candidate for future wearable electrochemical energy devices with superior transparency and stretchability.
Stretchable and transparent electrodes (STEs) are vital and indispensable in developing optoelectronic devices aiming for next-generation flexible electronics. However, the fabrication of high-performance electrodes with both good stretchability and transparency is still challenging. To balance the conductivity and stretchability trade-offs in previously reported STEs, the STEs with embedded metal nickel (Ni) meshes in polydimethylsiloxane (PDMS) in this study are designed and tested. The STEs show high optical transparency (81.6%), high stretchability (40%) and low resistance (0.44 Ω). We can further improve the mechanical stretchability of the STEs by designing the Ni mesh patterns, while still maintaining optical and electrical properties.. In addition, this fabrication strategy versatile without sophisticated processing procedures, opening possibility for high-throughput, large-volume, and low-cost production, which would lead to potential applications in wearable medical equipment and transparent electronic devices.