Facile one-pot synthesis of NiCo2Se4-rGO on Ni foam for high performance hybrid supercapacitors

One-Step Microwave Synthesis of NiSb/NiSe Nanomaterials for High Performance Supercapacitors

This paper investigated the preparation of NiSb/NiSe nanomaterials using a microwave method and explored their electrochemical properties and potential applications in supercapacitors. The NiSb/NiSe nanomaterials were synthesized on nickel foam using microwave radiation, resulting in uniformly distributed flower-like nanostructures. This structure not only provided abundant electrochemical reaction sites, but also improved the electrical conductivity and ion diffusion, contributing to the overall performance of supercapacitors. Electrochemical tests showed that the NiSb/NiSe material exhibited a high specific capacity of 525 mAh g-1 at 1 A g⁻1 and maintained 65% capacity after 8000 cycles, demonstrating excellent cycling stability and battery-type charge storage capability. In addition, a hybrid supercapacitor assembled using NiSb/NiSe as the anode material and activated carbon (AC) as the cathode material achieved an energy density of 100.34 Wh kg-1 at a power density of 774.9 W kg-1, significantly enhancing energy storage efficiency. The effect of different microwave powers and reaction times on the morphology and electrochemical properties of the materials were further investigated, with the optimal preparation conditions found to be 800 W and 150 s. The NiSb/NiSe materials synthesized under this condition not only have the best electrochemical properties, but also exhibit low charge transfer impedance and excellent electrical conductivity. In summary, NiSb/NiSe flower-like nanomaterials as supercapacitor electrode materials demonstrate great potential for energy storage applications due to their high specific capacity, good cycling stability and high energy density.

In situ synthesis of bimetallic chalcogenides with highly conductive carbon nanotubes for efficient symmetric hybrid supercapacitors

Achieving high energy density and long cycle stability in energy storage devices necessitates excellent electrochemical performance, which often relies on the innovative structural design of the materials under investigation. Therefore, hybrid supercapacitors are crucial in the realm of energy storage devices. The elevated energy and power densities, combined with various energy storage mechanisms, significantly improve electrochemical performance. Here, we developed a highly efficient electrode material, carbon nanotube-metal chalcogenides (CNT-CuNiSe2), using a simple one-pot reflux method (in situ). The enhanced energy storage performance was achieved by synergising CuNiSe2 with the pi-cloud of CNTs, resulting in enhanced specific capacitance retention over prolonged cycling stability. The hybrid supercapacitor electrode was formed by combining conducting carbon cloth (CC) with CNT-CuNiSe2 as a hybrid material, referred to as the CC/CNT-CuNiSe2 material. The fabricated hybrid electrode materials demonstrated excellent potential for energy storage. CC/CNT-CuNiSe2 exhibited excellent energy storage capabilities, achieving a specific capacitance of 957.06 F g-1 at 1 A g-1. Hybrid supercapacitors with high energy and power density were developed using conducting carbon cloth and CNT-CuNiSe2, designated as CC/CNT-CuNiSe2//CC/CNT-CuNiSe2. The hybrid capacitor device demonstrated a capacitance of 265.586 F g-1, along with an energy density of 82.99 W h kg-1 at a power density of 1511.35 W kg-1. When charged and discharged at 4 A g-1, the hybrid capacitor device displayed an impressive capacitance retention of 101.3% over 6000 continuous cycles.

Unveiling the redox electrochemical kinetics of interconnected wrinkled microspheres of binary Cu2-xSe/Ni1-xSe as battery-type electrode for advanced supercapatteries

Developing a rational design of nanoarchitechtures with excellent electrochemical behaviors is an ultimate and unique strategy to enhance the redox electrokinetics of battery-type electrode materials. Herein, we demonstrate a hierarchical composite comprising interconnected wrinkled micro-solid sphere (ICWMS)-like binary copper selenide/nickel selenide over nickel foam (Cu2-xSe/Ni1-xSe/NF) prepared via a wet chemical synthetic protocol and utilized as an effective positrode for improved supercapaterry performance. The binary Cu2-xSe/Ni1-xSe/NF electrode considerably improved the electroactive surface area and facilitated ultrafast redox electrochemistry in an alkaline electrolyte medium. Remarkably, the binary Cu2-xSe/Ni1-xSe/NF electrode afforded the highest specific capacity of 368 ± 1C/g at 1 A/g greater than that of pristine single selenide electrodes (Cu2Se and NiSe) in a three-electrode setup which might be attributed to its large surface area, synergism between Ni and Cu, and specific morphology. Moreover, a coin cell supercapattery with the binary Cu2-xSe/Ni1-xSe/NF positrode and a porous activated carbon-on-nickel-foam negatrode was constructed, which exhibited excellent energy-storage characteristics in terms of capacity (87.5 ± 1 mAh/g), specific energy (39.3 Wh kg-1), specific power (450 W kg-1), and capacity retention (91.8 %). This simple fabrication approach of hierarchically designed Cu2-xSe/Ni1-xSe/NF paves the way for utilizing it as the promising positrode for high-performance supercapattery.

Recent Advancements in Chalcogenides for Electrochemical Energy Storage Applications

Energy storage has become increasingly important as a study area in recent decades. A growing number of academics are focusing their attention on developing and researching innovative materials for use in energy storage systems to promote sustainable development goals. This is due to the finite supply of traditional energy sources, such as oil, coal, and natural gas, and escalating regional tensions. Because of these issues, sustainable renewable energy sources have been touted as an alternative to nonrenewable fuels. Deployment of renewable energy sources requires efficient and reliable energy storage devices due to their intermittent nature. High-performance electrochemical energy storage technologies with high power and energy densities are heralded to be the next-generation storage devices. Transition metal chalcogenides (TMCs) have sparked interest among electrode materials because of their intriguing electrochemical properties. Researchers have revealed a variety of modifications to improve their electrochemical performance in energy storage. However, a stronger link between the type of change and the resulting electrochemical performance is still desired. This review examines the synthesis of chalcogenides for electrochemical energy storage devices, their limitations, and the importance of the modification method, followed by a detailed discussion of several modification procedures and how they have helped to improve their electrochemical performance. We also discussed chalcogenides and their composites in batteries and supercapacitors applications. Furthermore, this review discusses the subject’s current challenges as well as potential future opportunities.

Synthesis of bimetallic nickel cobalt selenide particles for high-performance hybrid supercapacitors

Supercapacitors are known as promising excellent electrochemical energy storage devices because of their attractive features, including quick charge and discharge, high power density, low cost and high security. In this work, a series of litchi-like Ni-Co selenide particles were synthesized via a simple solvothermal method, and the Ni-Co compositions were carefully optimized to tune the charge storage performance, charge storage kinetics, and conductivity for battery-like supercapacitors. Interestingly, the optimal sample Ni0.95Co2.05Se4 exhibits a high capacity of 1038.75 F g-1 at 1 A g-1 and superior rate performance (retains 97.8% of the original capacity at 4 A g-1). Moreover, an asymmetric supercapacitor device was assembled based on the Ni0.95Co2.05Se4 cathode and activated carbon anode. The device of Ni0.95Co2.05Se4//active carbon (AC) reveals a peak energy density of 37.22 W h kg-1, and the corresponding peak power density reaches 800.90 W kg-1. This work provides a facile and effective way to synthesize transition metal selenides as high-performance supercapacitor electrode materials.

Hierarchical NiCo2Se4 nanoneedles/nanosheets with N-doped 3D porous graphene architecture as free-standing anode for superior sodium ion batteries

In order to cope with the problem of insufficient lithium metal reserves, sodium ion batteries (SIBs) are proposed and extensively studied for the next-generation batteries. In our work, hierarchical NiCo₂Se₄ nanoneedles/nanosheets are deposited on the skeleton of N-doped three dimensional porous graphene (NPG) by a convenient solvothermal method and subsequent gas-phase selenization process. Compared with NiCo₂Se₄ powder, the optimized NiCo₂Se₄/N-doped porous graphene composite (denoted as NCS@NPG) as self-supporting anode exhibits the excellent electrode activity for SIBs, with a specific capacity of 500 mAh/g and 257 mAh/g at a current density of 0.2 A/g and 6.4 A/g, respectively. The high specific capacity as well as rate capacity can be attributed to the three-dimensional graphene skeleton with high electrical conductivity and pore structure, which provides convenient ion and electron transmission channels.

Solution-processed graphene oxide electrode for supercapacitors fabricated using low temperature thermal reduction

We present a low temperature and solution-based fabrication process for reduced graphene oxide (rGO) electrodes for electric double layer capacitors (EDLCs). Through the heat treatment at 180 °C between the spin coatings of graphene oxide (GO) solution, an electrode with loosely stacked GO sheets could be obtained, and the GO base coating was partially reduced. The thickness of the electrodes could be freely controlled as these electrodes were prepared without an additive as a spacer. The GO coating layers were then fully reduced to rGO at a relatively low temperature of 300 °C under ambient atmospheric conditions, not in any chemically reducing environment. Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) results showed that the changes in oxygen functional groups of GO occurred through the heat treatments at 180 and 300 °C, which clearly confirmed the reduction from GO to rGO in the proposed fabrication process at the low thermal reduction temperatures. The structural changes before and after the thermal reduction of GO to rGO analyzed using Molecular Dynamic (MD) simulation showed the same trends as those characterized using Raman spectroscopy and XPS. An EDLC composed of the low temperature reduced rGO-based electrodes and poly(vinyl alcohol)/phosphoric acid (PVA/H₃PO₄) electrolyte gel was shown to have high specific capacitance of about 240 F g⁻¹ together with excellent energy and power densities of about 33.3 W h kg⁻¹ and 833.3 W kg⁻¹, respectively. Furthermore, a series of multiple rGO-based EDLCs was shown to have fast charging and slow discharging properties that allowed them to light up a white light emitting diode (LED) for 30 min.

We present a low temperature and solution-based fabrication process for reduced graphene oxide (rGO) electrodes for electric double layer capacitors (EDLCs).