Rational Design of Porous Nanowall Arrays of Ultrafine Co₄N Nanoparticles Confined in a La₂O₂CN₂ Matrix on Carbon Cloth for a High-Performing Supercapacitor Electrode

Abstract

Transition metal nitrides (TMNs) have received special concern as important energy storage materials, owing to their high conductibility, good mechanical strength, and superior corrosion resistance. However, their insufficient capacitance and poor cycling stability limit their practical applications for supercapacitors. Here, a novel three-dimensional (3D) self-supported integrated electrode consisted of porous nanowall arrays of ultrafine cobalt nitride (Co4N) nanoparticles encapsulated in a lanthanum oxycyanamide (LOC) matrix on carbon cloth (Co4N@LOC/CC) for outstanding electrochemical energy storage is rationally designed and fabricated. The 3D monolithic configuration of porous nanowall arrays facilitates the mass/charge transfer, the exposure of electroactive sites, and the enhancement of electrical conductivity. Meanwhile, the unique core–shell structure of Co4N@LOC can prevent ultrafine Co4N nanoparticles from sintering, agglomeration, and oxidation and promotes electron transfer dynamics during the redox reaction, meanwhile enhancing the stability of the electrode. Additionally, the synergy of Co4N and LOC can result in an efficient electron/ion transport in the process of the charge–discharge. Because of these features, the Co4N@LOC/CC electrode displays superior specific capacitance (895.6 mF cm–2 or 613.4 F g–1 at 1 mA cm–2) and admirable cycling durability (87.9% capacitance reservation after 10 000 cycles), surpassing the majority of nitride-based electrodes reported thus far. Furthermore, after being assembled into an asymmetric supercapacitor using active carbon (AC) as an anode, the obtained Co4N@LOC/CC//AC/CC device displays a high energy density of 41.7 Wh kg–1 at the power density of 875.8 W kg–1 with a high capacitance reservation of 87.6% after 5000 cycles at 2 mA cm–2. This work offers an efficient approach of combining TMNs with rare earth compounds to enhance the capacitance and stability of TMNs for supercapacitor electrodes.

Corrosion in Supercapacitors- An Overview

“…Corrosion of the NiCo foam used as current collector and electrochemical dissolution of the MnO x used as active mass were identified as causes of cell performance degradation [121]. Metal nitrides, in particular TiN, have been claimed to show high corrosion resistance in supercapacitor applications [122]; see also [123]. Similar claims for metal oxynitrides [124,125] and MXenes [126] have been reported.…”

Analyzing the charge contributions of metal–organic framework derived nanosized cobalt nitride/carbon composites in asymmetrical supercapacitors

“…For instance, Cao et al confined Co 4 N nanoparticles in the La 2 O 2 CN 2 matrix on carbon cloth for supercapacitor applications. 13 The ultrafine Co 4 N nanoparticles promoted the electron transfer dynamics which enhance the capacitance of the electrode. The electrode exhibits a low potential window (0–0.5 V) in 1 M KOH solution.…”

Yttrium Oxide Nanoclusters Boosted Fe‐N4 and Fe4N Electrocatalyst for Future Zinc–Air Battery

“…[31][32][33][34][35] Rare earth (RE) elements are popular additives to regulate the electronic structures of transition metals owing to their unique orbital structure. [36][37][38][39][40][41] Liu et al utilized Gd to tailor the size of Ni nanoparticles and affect the local electron densities of Ni 3d orbitals, thereby increasing the CO 2 reduction reaction activity. [42] Wang et al co-introduced Fe and Ce into the nitrogen-doped carbon aerogel to optimize the pore structure and significantly increase the pyridinic nitrogen content.…”

“…Rare earth (RE) elements are popular additives to regulate the electronic structures of transition metals owing to their unique orbital structure. [ 36–41 ] Liu et al. utilized Gd to tailor the size of Ni nanoparticles and affect the local electron densities of Ni 3d orbitals, thereby increasing the CO 2 reduction reaction activity.…”