Chemical formation of soft metal electrodes for flexible and wearable electronics

Zhang

Adv Materials Technologies

2019

Self Cite

The paucity of soft materials with both high electrical conductivity and the capability to maintain their superior conductance under large and complex mechanical deformations is a crucial barrier hindering the development of stretchable electronics toward practical applications. A type of ultrastretchable hybrid electrodes composed of silver nanowires (AgNWs) and multiwalled carbon nanotubes (CNTs) are reported, which show sheet resistance as low as 7.1 Ω sq.−1 and a small resistance increase of only 42% when uniaxially stretched to a strain of 580%. The hybrid electrodes can also withstand equibiaxial stretching, showing a resistance increase of 100% at a strain of 200%, and survive at least 1500 stretching/releasing cycles with negligible resistance change. The key to such performance is welding the loosely stacked AgNWs and CNTs into one integrated network with the aid of capillary force. When coated onto both sides of a polyacrylate‐based elastomer, VHB, the AgNW/CNT hybrid films can serve as excellent compliant electrodes of a dielectric elastomer actuator, causing a maximum actuated areal strain of 190% with a relatively low starting electric field of 11.6 V µm−1. These ultrastretchable AgNW/CNT electrodes will pave the way for the rapid development of high‐end stretchable electronics.

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Ultrastretchable Hybrid Electrodes of Silver Nanowires and Multiwalled Carbon Nanotubes Realized by Capillary‐Force‐Induced Welding

Zhang

Adv Materials Technologies

2019

Self Cite

“…in many applications, such as environmental sensing, [1] wearable and flexible electronics, [2][3][4][5] and electrochemical energy conversion. [6,7] Carbon fiber based networks, including non-woven carbon papers and woven carbon cloths, are commonly used as rigid GDEs, [8,9] while carbon nanotube based GDEs have recorded applications in flexible and stretchable electronic devices.…”

Section: Doi: 101002/aelm201900767mentioning

confidence: 99%

Conformal Cu Coating on Electrospun Nanofibers for 3D Electro‐Conductive Networks

Jiang

Pan

et al. 2019

Adv Elect Materials

Electro‐conductive nanofiber networks have potential applications as gas diffusion electrodes (GDEs) operating at solid–liquid–gas three‐phase interfaces. Flexible GDEs are developed, based on a versatile method of conformally coating a Cu layer on membranes consisting of stacked electrospun nonconductive polymer nanofibers. The Cu coating, comprising fine‐grained Cu crystals, has an average thickness of circa 50 nm and a root‐mean‐square roughness of circa 5.3 nm, maintaining the topography of polymer nanofibers. For nanofiber membranes with a thickness ranging in a few micrometers, the conformal Cu layer coats all nanofibers in the outermost layers as well as in the bulk of the membrane. All demonstrated Cu‐coated nanofiber networks have sheet resistance <2.4 Ω◽, and gas permeability in the order of 10−13 to 10−15 m2, which are comparable to some commercialized carbon based micro‐/nanofiber GDEs. Particularly, these conductive nanofiber networks have excellent bending durability, with negligible conductivity degradation after 10 000 bending test cycles. The high conductivity, gas permeability, and flexibility of these 3D nanofiber networks allow for applications as GDEs into various flexible electrochemical devices.

“…Especially, the metal modified fabric, constructed by a facile electroless plating process, displayed a comparable conductivity to metal without sacrificing the flexibility. [ 6 ] However, conventional micromachining processes such as photolithography and screen printing are impracticable to the fabrication of textile microelectrodes. Encouragingly, the laser method can be a better choice in term of the briefness, speed, and universality.…”

Section: Introductionmentioning

confidence: 99%

Wearable Textile‐Based Co−Zn Alkaline Microbattery with High Energy Density and Excellent Reliability

Hong

Guo

et al. 2020

Small

Wearable in‐plane Zn‐based microbatteries are considered as promising micropower sources for wearable electronics due to their high capacity, low cost, high safety, and easy integration. However, their applications are severely impeded by inadequate energy density arising from unsatisfactory capacity of cathode and poor cycling stability caused by degradation of electrode materials and Zn dendrite. Additionally, the short‐circuit induced safety issue caused by Zn dendrite is still a roadblock for Zn‐based microbatteries. Herein, a textile‐based Co−Zn microbattery with ultrahigh energy density and excellent cycling stability is demonstrated. Benefiting from the fast electron transport of three‐dimensional (3D) porous Ni‐coated textile and synergistic effect from the hierarchical Co(OH)2@NiCo layered double hydroxide (LDH) core−shell electrode, the fabricated Co−Zn microbattery with high flexibility delivers superior energy/power densities of 0.17 mWh cm−2/14.4 mW cm−2, outperforming most reported micro energy storage devices. Besides, the trench‐type configuration as well as the 3D porous Zn@carbon clothes can avoid the short‐circuit‐induced safety issues, resulting in excellent cycling stability (71% after 800 cycles). The unique core−shell structure and novel configuration provide a brand‐new design strategy for high‐performance wearable in‐plane microdevices.