Hydroquinone Resin Induced Carbon Nanotubes on Ni Foam As Binder-Free Cathode for Li–O₂ Batteries

Abstract

In this work, hydroquinone resin was used to grow carbon nanotubes directly on Ni foam. The composites were obtained via a simple carbonization method, which avoids using the explosive gaseous carbon precursors that are usually applied in the chemical vapor deposition method. When evaluated as cathode for Li-O2 batteries, the binder-free structure showed enhanced ORR/OER activities, thus giving a high rate capability (12690 mAh g(-1) at 200 mA g(-1) and 3999 mAh g(-1) at 2000 mA g(-1)) and outstanding long-term cycling stability (capacity limited 2000 mAh g(-1), 110 cycles at 200 mA g(-1)). The excellent battery performance provides new insights into designing a low-cost and high-efficiency cathode for Li-O2 batteries.

A Composite of Carbon‐Wrapped Mo2C Nanoparticle and Carbon Nanotube Formed Directly on Ni Foam as a High‐Performance Binder‐Free Cathode for Li‐O2 Batteries

“…Transmission electron microscope (TEM) images of the MCN composite detached from the Ni foam via ultrasonication in ethanol are shown (Figure d–g). Worm‐like carbon nanotubes with dark heads can also be observed in the TEM image (Figure d); this is consistent with the SEM observations and results reported in our previous work . Elemental mapping of the carbon nanotubes suggests the dark head at the end of the carbon nanotube is Ni nanoparticles (Figure S2a, Supporting Information).…”

“…The increase in the specific capacity of MCN can be ascribed to the high ORR/OER activities and the extra space provided by the carbon nanotubes for the deposition of discharge products. Compared with the cathode comprised solely of carbon nanotubes which was reported in our previous work, both the charge and discharge overpotentials have been reduced. This indicates that the catalyst is affected by the presence of Mo 2 C nanoparticles.…”

“…Elemental mapping of the carbon nanotubes suggests the dark head at the end of the carbon nanotube is Ni nanoparticles (Figure S2a, Supporting Information). Thus, the formation of these carbon nanotubes is driven by Ni nanoparticles, following a “tip‐growth” mechanism well‐illustrated in our previous work . These carbon nanotubes provide a large amount of space for the discharge product deposition, contributing to the specific capacity.…”

“…Preparation of MCN Composites : Ni foam was cut into 15 mm disks and washed with acetone followed by HCl (0.1 m ) and deionized water. Hydroquinone resin was prepared following our previously published work . The resin solution was stirred for 2 h, and ammonium heptamolybdate tetrahydrate (0.5 g) was dissolved in deionized water (2 mL).…”

Recent Progress on Catalysts for the Positive Electrode of Aprotic Lithium-Oxygen Batteries †

“…Carbon materials generally possess many merits such as excellent electrical conductivity, good chemical and thermal stability, light weight, high surface area, sufficient resources, and low cost [41,42]. As a result, various carbon materials, including activated carbon [43], carbon paper [44,45], carbon nanotubes (CNT) [46][47][48][49], graphene [42,[50][51][52][53][54], and mesoporous carbon [55][56][57][58], have been used as the positive electrode for Li-O 2 batteries. In this section, various strategies to design high-performance carbon positive-electrode catalysts are discussed, including structural design, heteroatom doping, defect modification, and synergy of the above three strategies.…”