Free-Standing Porous Carbon Nanofiber/Ultrathin Graphite Hybrid for Flexible Solid-State Supercapacitors

Abstract

A micrometer-thin solid-state supercapacitor (SC) was assembled using two pieces of porous carbon nanofibers/ultrathin graphite (pCNFs/G) hybrid films, which were one-step synthesized by chemical vapor deposition using copper foil supported Co catalyst. The continuously ultrathin graphite sheet (∼ 25 nm) is mechanically compliant to support the pCNFs even after etching the copper foil and thus can work as both current collector and support directly with nearly ignorable fraction in a SC stack. The pCNFs are seamlessly grown on the graphite sheet with an ohmic contact between the pCNFs and the graphite sheet. Thus, the accumulated electrons/ions can duly transport from the pCNFs to graphite (current collector), which results in a high rate performance. The maximum energy density and power density based on the whole device are up to 2.4 mWh cm(-3) and 23 W cm(-3), which are even orders higher than those of the most reported electric double-layer capacitors and pseudocapacitors. Moreover, the specific capacitance of the device has 96% retention after 5000 cycles and is nearly constant at various curvatures, suggesting its wide application potential in powering wearable/miniaturized electronics.

Porous One‐Dimensional Nanomaterials: Design, Fabrication and Applications in Electrochemical Energy Storage

“…2017, 29, 1602300 www.advancedsciencenews.com www.advmat.de porous carbon fiber films via electrospinning (Figure 22a). [53] This flexible supercapacitor device exhibited high volumetric energy density (2.4 mWh cm −3 ) and power density (23 W cm −3 ). The all solid-state symmetric supercapacitor exhibited excellent performance even under bending and twisting (Figure 22b).…”

“…[53,80,286,287] Recently, Huang et al [80] produced bamboo-like Adv. To avoid the drawback of binders, porous nanofibers can be assembled into binder-free and self-standing films, which is promising in flexible energy storage applications.…”

“…[45][46][47][48][49] Electrochemical energy storage technology, in particular, benefits from porous materials because pores enable higher surface area and faster electrolyte access to active walls. [50][51][52][53][54][55][56][57][58][59][60][61][62][63][64][65][66][67][68] The intent of this review is to summarize recent advances related to this topic and, more importantly, to provide systematic understanding of porous 1D nanomaterials and their advantages for electrochemical energy storage. As shown in Figure 1, we define different types of (3 of 39) 1602300 porous 1D nanostructures to include general porous 1D nanostructure, hollow 1D geometry (also named a tubular nanostructure), hierarchical porous 1D architecture, nanoparticles in porous 1D configuration, and porous 1D nanoarray.…”

Ultrahigh-rate supercapacitors with large capacitance based on edge oriented graphene coated carbonized cellulous paper as flexible freestanding electrodes

“…Furthermore, these thin layers with hierarchical pore structure can be stacked for thick electrodes to obtain much larger electrode-area-specific capacitance without sacrificing frequency and volumetric capacitance performance, suggesting such an electrode architecture being more practical. As another merit, these thin electrodes are also flexible, potentially for bendable ECs [27,28]. In addition, it is worth to emphasize that cellulous is the most common polymer on the earth with an estimated 10 11 tons of production annually.…”

Polypyrrole/nickel sulfide/bacterial cellulose nanofibrous composite membranes for flexible supercapacitor electrodes

“…Supercapacitors, also known as electrochemical capacitors, have drawn much attention as a novel energy storage device because of their high power density, long cycling stability, and fast charging/discharging rate Xu et al 2013Xu et al , 2015aLi et al 2014a, b;Zhu et al 2014;Liu et al 2015b;Qin et al 2015). According to the charge storage mechanisms as well as the use of electrode materials, supercapacitors can be categorized into two types:…”