High Peel Strength and Flexible Aligned Carbon Nanotubes/Etched Al Foil Composites with Boosted Supercapacitor and Thermal Dissipation Performances

Abstract

The peel strength between the aligned carbon nanotubes (ACNTs) and substrate is a critical issue for the structural stability of the ACNTs-based composites. A poor ACNTs-substrate adhesion may cause unreliable and a short service life of the device. In this work, ACNTs are grown on the etched Al foil with largely improved bonding strength by a direct thermal chemical vapor deposition (CVD) synthesis. In the interface part of the ACNTs adjacent to the etched Al substrate, the ACNTs tangled together as 'tiny twine balls' with irregular shape are embedded in the pores of the etched Al foil, similar like the roots of a plant. Such unique structure generates strong bonding strength between as-grown ACNTs and etched Al substrate. The measured peel strength was 76.8 N m-1 compared to the smooth surface Al foil without etching was 53.6 N m-1. Besides, the ACNTs attached to etched Al foil firmly in comparison with the ACNTs have been separated from the smooth surface Al foil after peel strength testing. A 'plant growth' mechanism is proposed to illustrate the growth procedure. When the as-prepared ACNTs/etched Al foil composites are used as supercapacitor (SC) electrodes alone, they deliver the specific capacity (Csp) of 11.3 F g-1. By contrast, after the PANI or MnO2 are post-synthesized on the ACNTs/etched Al substrate, the PANI/ACNTs and MnO2/ACNTs composites can reach a mass-normalized Csp of 488.2 F g-1 and 117.6 F g-1 , respectively. The ACNTs/etched Al foil are also applied as thermal dissipation material for a 24W LED light. The final stable working temperature decreases from 106.3℃ to 82.3℃ and the temperature rise rate between 30℃ and 82℃ decreases from 0.19℃ s-1 to 0.04℃ s-1 after the ACNTs/etched Al foil are stuck to the backboard of LED light. The excellent electrical and outstanding thermal conductivities of ACNTs/etched Al foil composites are mainly attributed to the much higher bonding strength and improved interface contact. The results enlighten and promote the design and preparation of ACNTs composites with high peel strength to develop high-performance electrical and thermal management devices.

Critical Role of the Acetylene Content and Fe/C Ratio on the Thickness and Density of Vertically Aligned Carbon Nanotubes Grown at Low Temperature by a One-Step Catalytic Chemical Vapor Deposition Process

“…In addition, according to the present results, the catalyst feeding is also an important parameter to control the VACNT growth dynamic, since for low acetylene content, increasing the Fe/C ratio enables us to reach higher mean growth rates on both grade Al substrates. Even more interestingly, this resulting growth enhancement is as high as the surface roughness of the Al substrate is low, suggesting that the growth or the agglomeration of catalyst nanoparticles are favored in the grooves [ 18 , 26 , 39 , 54 ], involving a change in their behavior, especially the formation of amorphous carbon or carbon onions, which contributes to catalyst nanoparticle poisoning and eventually to their deactivation.…”

“…In addition, the introduction of oxygen was reported as beneficial for the growth of VACNTs, allowing carpet growth of up to a millimeter thickness [ 24 , 36 , 37 ]. Most of the oxygen sources used are H 2 O, CO 2 , CO, C 2 H 5 OH, O 2 or air [ 14 , 24 , 25 , 36 , 37 , 38 , 39 ].…”

“…This one-step CCVD processes enables the constant renewing of the catalyst particles as reported at high temperature (850 °C) by Castro et al [ 40 ]. However, in the literature, very few studies of VACNT synthesis with a single-step method are reported at a low temperature and atmospheric pressure [ 27 , 39 , 41 , 42 , 43 , 44 ]. Unlike two-step processes, here we can assume that particle deactivation will be limited.…”

Ultrahigh‐Areal Capacitance Flexible Supercapacitors Based on Laser Assisted Construction of Hierarchical Aligned Carbon Nanotubes

“…[1] Based on the GCD curves, the areal capacitance of the hierarchical VACNTs electrode are calculated by formula (3) and the value is ≈1300 mF cm −2 , which is higher than most reported carbon-based SCs (Table 1). [13,[22][23][24][25][26][27][28][29][30][31][32][33][34][35] In addition, the specific capacitance can also be obtained by means of CV curve integration, namely Equation (4).…”

“…CNT forests [35] EDLC SS 1.5 5.99 5.2 95% (10,000) ACNT electrode [13] EDLC Al foil 1.1 11.4 5.4 93.7% (10,000) CN/CNT composite [36] EDLC Si NA 110 2.2 93% (10,000) GNCN electrode [37] EDLC Ni 0.5 0.15 331 93% (10,000) CNT/TiO 2 electrode [38] EDLC NA 1 83 NA 70% (1000)…”