Highly Ordered Mesoporous CuCo₂O₄ Nanowires, a Promising Solution for High-Performance Supercapacitors

Abstract

The search for faster, safer, and more efficient energy storage systems continues to inspire researchers to develop new energy storage materials with ultrahigh performance. Mesoporous nanostructures are interesting for supercapacitors because of their high surface area, controlled porosity, and large number of active sites, which promise the utilization of the full capacitance of active materials. Herein, highly ordered mesoporous CuCo2O4 nanowires have been synthesized by nanocasting from a silica SBA-15 template. These nanowires exhibit superior pseudocapacitance of 1210 F g–1 in the initial cycles. Electroactivation of the electrode in the subsequent 250 cycles causes a significant increase in capacitance to 3080 F g–1. An asymmetric supercapacitor composed of mesoporous CuCo2O4 nanowires for the positive electrode and activated carbon for the negative electrode demonstrates an ultrahigh energy density of 42.8 Wh kg–1 with a power density of 15 kW kg–1 plus excellent cycle life. We also show that two asymmetric devices in series can efficiently power 5 mm diameter blue, green, and red LED indicators for 60 min. This work could lead to a new generation of hybrid supercapacitors to bridge the energy gap between chemical batteries and double layer supercapacitors.

Hierarchical CuCo2O4 nanobelts as a supercapacitor electrode with high areal and specific capacitance

“…This increasing trend of both area and peak separation is due to polarization and Ohmic resistance during the redox reaction [24]. The possible electrochemical reaction of CuCo2O4 during redox reaction in alkaline solutions was as follows [25],…”

“…Recently, highly ordered mesoporous CuCo2O4 nanowire electrode material was studied for supercapacitors by Pendashteh et al [25]. They achieved first discharge specific capacitance of 1210 F g -1 , whereas the areal capacitance was only 0.6 F cm -2 .…”

Mesoporous materials for energy conversion and storage devices

“…Pseudocapacitance is related to Faradaic reactions at the electrode/electrolyte interface and is at least 10 times higher than double-layer capacitances 169 . Therefore, as for EDLCs, mesoporous materials represent a promising candidate towards harvesting the full pseudocapacitance 170 . Pseudocapacitors usually suffer from low power density and short cycle life because of the poor electrical conductivity and stability of the active materials, such as conducting polymers and metal oxides 169,170 .…”

“…Therefore, as for EDLCs, mesoporous materials represent a promising candidate towards harvesting the full pseudocapacitance 170 . Pseudocapacitors usually suffer from low power density and short cycle life because of the poor electrical conductivity and stability of the active materials, such as conducting polymers and metal oxides 169,170 . In this regard, mesostructured porous carbons are viable alternative hosts because they can increase the electrical conductivity and mechanical stability, as well as provide a confined space for the growth of active species at the nanoscale [171][172][173][174] .…”

A one step processed advanced interwoven architecture of Ni(OH)2 and Cu nanosheets with ultrahigh supercapacitor performance

“…8(a) shows typical CV curves of the ASC tested in a 2 M KOH electrolyte at various scan rates between 0 and 1.5 V. The clearly observed redox peaks indicate the pseudocapacitance contribution from the positive electrode. 29,30 The galvanostatic discharge curves acquired at different current densities are exhibited in Fig. 8(b).…”