3D Hierarchical Porous Carbon Aerogel Electrocatalysts Based on Cellulose/Aramid Nanofibers and Application in High-Performance Zn–Air Batteries

Abstract

Three-dimensional (3D) carbon aerogels (CAs) are composed of interconnected networks and emerge as appealing platforms for the combination of heteroatom dopants, defective sites, and hierarchical porous structures. Here, we propose an effective and sustainable strategy to construct TOCNF/ANF-Cd hydrogels/aerogels using TEMPO-oxidized cellulose nanofibers (TOCNFs), thermally stabilized aramid nanofibers (ANFs), and low-boiling-point Cd 2+ . Hierarchical porous N-doped aerogel catalysts (N/CA-Cd) with TOCNF/ANF synergistic cross-linking were obtained by moderate temperature pyrolysis. Apart from serving as a source of N, ANF also improves carbon retention and graphitization, increasing the electrical conductivity of carbon aerogels. Due to the spatially continuous structure and multiscale porous structure and abundant N dopants and edges/defects, the as-obtained N/CA 0.5 -Cd carbonaceous catalysts manifest an impressive electrocatalytic efficacy with a positive half-wave potential (0.86 V). In particular, the Zn−air batteries assembled with N/ CA 0.5 -Cd as the air cathode catalyst have an excellent peak power density of 186 mW cm −2 and a splendid specific capacity of 730 mA h g −1 .

Heteroatom tuning in agarose derived carbon aerogel for enhanced potassium ion multiple energy storage

“…The N 1s spectrum (Figure 1H) exhibits the presence of pyridinic-N (398.54 eV), pyrrolic-N (400.03 eV), N-O (401.79 eV), and N-Q (401.14 eV). 46 Pyridinic-N and pyrrolic-N are known to create defects and furnish electrically active sites, which aid in the storage of potassium ions. Quaternary amine nitrogen is in favor to increase the wettability of CA.…”

“…The aforementioned oxygen functionalities undergo redox reactions during the charge and discharge processes, thereby imparting additional pseudocapacitance to the material. The N 1s spectrum (Figure 1H) exhibits the presence of pyridinic‐N (398.54 eV), pyrrolic‐N (400.03 eV), N–O (401.79 eV), and N–Q (401.14 eV) 46 . Pyridinic‐N and pyrrolic‐N are known to create defects and furnish electrically active sites, which aid in the storage of potassium ions.…”

Recent Research Progress of Paper‐Based Supercapacitors Based on Cellulose

“…The electrode materials commonly used in EDLC are carbon materials, such as activated carbon, [ 61 ] graphene, [ 62 ] carbon nanotubes, [ 63 ] and carbon nanomaterials. [ 64 ] Pseudocapacitance stores energy through the Faraday reaction of electrode materials. Compared with EDLC, pseudocapacitor supercapacitors exhibit higher energy storage capacity.…”

A low-cost and large-area modular nickel electrode on aramid fabric for efficient solar-driven water electrolysis

“…Aramid has been used for re-retardant applications due to its excellent chemical stability and physical strength. Although aramidbased devices have been reported with impressive performance as supercapacitors and Zn-air batteries, 35,36 the application of aramid fabric was still based on a regenerated process of aramid hybridized with other materials to achieve physical strength and stability, rather than directly using the aramid fabric as the supporting substrate for the electrocatalyst. The Nicoated aramid electrode can be upscaled to >10 cm 2 , making it a modular device used for electrochemical water splitting.…”