Scalable Electrode Materials with Nanoporous Current Collector Shells for Supercapacitors with Ultrahigh Areal and Volumetric Capacitances

2021 ◽  
Author(s):  
Ruitao Zhou ◽  
Ying Li ◽  
Kwok Ho Lam
Keyword(s):  
Specific Capacitance ◽  
Power Density ◽  
High Power ◽  
Electrode Materials ◽  
Current Collector ◽  
High Power Density ◽  
Mass Loading ◽  
Active Materials ◽  
Limited Mass

Supercapacitor is characterized by its high power density, but the bottleneck is the limited mass loading and low specific capacitance of active materials in a single electrode. Although there have...

scholarly journals Electrochemical Performance of Aluminum Doped Ni1−xAlxCo2O4 Hierarchical Nanostructure: Experimental and Theoretical Study

Processes ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1750
Author(s):  
Deepa Guragain ◽  
Romakanta Bhattarai ◽  
Jonghyun Choi ◽  
Wang Lin ◽  
Ram Krishna Gupta ◽  
...  
Keyword(s):  
Energy Density ◽  
Electrochemical Performance ◽  
Band Gap ◽  
Specific Capacitance ◽  
Surface Area ◽  
Power Density ◽  
High Power ◽  
Energy Band ◽  
High Specific Capacitance ◽  
High Power Density

For electrochemical supercapacitors, nickel cobaltite (NiCo2O4) has emerged as a new energy storage material. The electrocapacitive performance of metal oxides is significantly influenced by their morphology and electrical characteristics. The synthesis route can modulate the morphological structure, while their energy band gaps and defects can vary the electrical properties. In addition to modifying the energy band gap, doping can improve crystal stability and refine grain size, providing much-needed surface area for high specific capacitance. This study evaluates the electrochemical performance of aluminum-doped Ni1−xAlxCo2O4 (0 ≤ x ≤ 0.8) compounds. The Ni1−xAlxCo2O4 samples were synthesized through a hydrothermal method by varying the Al to Ni molar ratio. The physical, morphological, and electrochemical properties of Ni1−xAlxCo2O4 are observed to vary with Al3+ content. A morphological change from urchin-like spheres to nanoplate-like structures with a concomitant increase in the surface area, reaching up to 189 m2/g for x = 0.8, was observed with increasing Al3+ content in Ni1−xAlxCo2O4. The electrochemical performance of Ni1−xAlxCo2O4 as an electrode was assessed in a 3M KOH solution. The high specific capacitance of 512 F/g at a 2 mV/s scan rate, 268 F/g at a current density of 0.5 A/g, and energy density of 12.4 Wh/kg was observed for the x = 0.0 sample, which was reduced upon further Al3+ substitution. The as-synthesized Ni1−xAlxCo2O4 electrode exhibited a maximum energy density of 12.4 W h kg−1 with an outstanding high-power density of approximately 6316.6 W h kg−1 for x = 0.0 and an energy density of 8.7 W h kg−1 with an outstanding high-power density of approximately 6670.9 W h kg−1 for x = 0.6. The capacitance retention of 97% and 108.52% and the Coulombic efficiency of 100% and 99.24% were observed for x = 0.0 and x = 0.8, respectively. First-principles density functional theory (DFT) calculations show that the band-gap energy of Ni1−xAlxCo2O4 remained largely invariant with the Al3+ substitution for low Al3+ content. Although the capacitance performance is reduced upon Al3+ doping, overall, the Al3+ doped Ni1−xAlxCo2O4 displayed good energy, powder density, and retention performance. Thus, Al3+ could be a cost-effective alternative in replacing Ni with the performance trade off.

scholarly journals Hierarchical Carbon Microtube@Nanotube Core–Shell Structure for High-Performance Oxygen Electrocatalysis and Zn–Air Battery

2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Wenfu Xie ◽  
Jianming Li ◽  
Yuke Song ◽  
Shijin Li ◽  
Jianbo Li ◽  
...  
Keyword(s):  
Energy Density ◽  
Power Density ◽  
High Power ◽  
High Performance ◽  
Rational Design ◽  
Specific Capacity ◽  
High Mass ◽  
Core Shell ◽  
High Power Density ◽  
Mass Loading

AbstractZinc–air batteries (ZABs) hold tremendous promise for clean and efficient energy storage with the merits of high theoretical energy density and environmental friendliness. However, the performance of practical ZABs is still unsatisfactory because of the inevitably decreased activity of electrocatalysts when assembly into a thick electrode with high mass loading. Herein, we report a hierarchical electrocatalyst based on carbon microtube@nanotube core–shell nanostructure (CMT@CNT), which demonstrates superior electrocatalytic activity for oxygen reduction reaction and oxygen evolution reaction with a small potential gap of 0.678 V. Remarkably, when being employed as air–cathode in ZAB, the CMT@CNT presents an excellent performance with a high power density (160.6 mW cm−2), specific capacity (781.7 mAhg Zn −1 ) as well as long cycle stability (117 h, 351 cycles). Moreover, the ZAB performance of CMT@CNT is maintained well even under high mass loading (3 mg cm−2, three times as much as traditional usage), which could afford high power density and energy density for advanced electronic equipment. We believe that this work is promising for the rational design of hierarchical structured electrocatalysts for advanced metal-air batteries.

Chain rigidity modification to promote the electrochemical performance of polymeric battery electrode materials

2019 ◽  
Vol 7 (17) ◽  
pp. 10581-10588 ◽  
Author(s):  
Zhihui Niu ◽  
Huaxi Wu ◽  
Lei Liu ◽  
Gaole Dai ◽  
Shiyun Xiong ◽  
...  
Keyword(s):  
Energy Density ◽  
Electrochemical Performance ◽  
Power Density ◽  
High Power ◽  
Electrode Materials ◽  
High Power Density ◽  
Battery Materials ◽  
Chain Rigidity ◽  
Battery Electrode ◽  
Rigidity Modification

Tuning the chain rigidity enables high power density without sacrificing the volumetric energy density for polymeric battery materials.

scholarly journals Enhanced Supercapacitive Performance of Higher-Ordered 3D-Hierarchical Structures of Hydrothermally Obtained ZnCo2O4 for Energy Storage Devices

Nanomaterials ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 1206 ◽  
Author(s):  
Gutturu Rajasekhara Reddy ◽  
Nadavala Siva Kumar ◽  
Borelli Deva Prasad Raju ◽  
Gnanendra Shanmugam ◽  
Ebrahim H. Al-Ghurabi ◽  
...  
Keyword(s):  
Energy Storage ◽  
Specific Capacitance ◽  
Power Density ◽  
High Power ◽  
Cycle Performance ◽  
Elemental Distribution ◽  
High Power Density ◽  
Fast Charge ◽  
Two Samples ◽  
Charge Discharge

The demand for eco-friendly renewable energy resources as energy storage and management devices is increased due to their high-power density and fast charge/discharge capacity. Recently, supercapacitors have fascinated due to their fast charge–discharge capability and high-power density along with safety. Herein, the authors present the synthesis of 3D-hierarchical peony-like ZnCo2O4 structures with 2D-nanoflakes by a hydrothermal method using polyvinylpyrrolidone. The reaction time was modified to obtain two samples (ZCO-6h and ZCO-12h) and the rest of the synthesis conditions were the same. The synthesized structures were systematically studied through various techniques: their crystalline characteristics were studied through XRD analysis, their morphologies were inspected through SEM and TEM, and the elemental distribution and oxidation states were studied by X-ray photoelectron spectroscopy (XPS). ZCO-12h sample has a larger surface area (55.40 m2·g−1) and pore size (24.69 nm) than ZCO-6h, enabling high-speed transport of ions and electrons. The ZCO-12h electrode showed a high-specific capacitance of 421.05 F·g−1 (31.52 C·g−1) at 1 A·g−1 and excellent cycle performance as measured by electrochemical analysis. Moreover, the morphologic characteristics of the prepared hierarchical materials contributed significantly to the improvement of specific capacitance. The excellent capacitive outcomes recommend the 3D-ZnCo2O4 hierarchical peony-like structures composed of 2D-nanoflakes as promising materials for supercapacitors with high-performance.

scholarly journals Biomass-Derived Graphene-Based Materials Embedded with Onion-Like Carbons for High Power Supercapacitors

2021 ◽  
Author(s):  
SungHoon Jung ◽  
Pham Thi Huong ◽  
Shalini Sahani ◽  
Kumud Malika Tripathi ◽  
Byung Jun Park ◽  
...  
Keyword(s):  
Energy Storage ◽  
Power Density ◽  
Current Density ◽  
High Power ◽  
Electrode Materials ◽  
High Current Density ◽  
3D Structure ◽  
High Energy ◽  
High Energy Density ◽  
High Power Density

Abstract We report a facile method to produce composites of hierarchically porous graphene-based materials embedded with onion-like carbons (Gr-OLCs) for high power density supercapacitors. Gr-OLCs were produced from the mixture of glucose, thiourea, and ammonium chloride, through the condensation reaction and subsequent blow into three-dimensional (3D) structure, and carbonization process. Owing to its high surface area, hierarchical pore distribution, and interconnected carbon networks embedded with onion-like carbons, this carbon exhibited the specific capacitance of 140 F g-1 at a high current density of 64 A g-1. Highly porous and interconnected carbon structure tend to facilitate the movement of electrolyte ions within the electrode and provide an efficient pathway for the movement of charge carriers, resulting in an exceptionally high power density of 1,737 kW kg-1, while maintaining its high energy density of 30 Wh kg-1 at current density of 256 A g-1. Studies on the complex capacitance of the cell revealed that these carbon electrodes possess stable energy storage features with minimal capacitive loss, achieving both high power and energy densities. This work may provide a new type of carbon-based electrode materials which can meet the requirements for high power energy storage devices.

scholarly journals Fiber-Shaped Supercapacitors Fabricated Using Hierarchical Nanostructures of NiCo2O4 Nanoneedles and MnO2 Nanoflakes on Roughened Ni Wire

Energies ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 3127 ◽  
Author(s):  
Zhang ◽  
Shewale ◽  
Yun
Keyword(s):  
Energy Density ◽  
Power Density ◽  
High Power ◽  
Current Collector ◽  
High Energy ◽  
High Energy Density ◽  
Nickel Wire ◽  
High Power Density ◽  
Hierarchical Nanostructures ◽  
Roughened Surface

Electrostatic capacitors have high power density but low energy density. In contrast, batteries and fuel cells have high energy density but low power density. However, supercapacitors can simultaneously achieve both high power density and energy density. Herein, we propose a supercapacitor, in which etched nickel wire was used as a current collector due to its high conductivity. Two redox reactive materials, MnO2 nanoflakes and NiCo2O4 nanoneedles, were used in a hierarchical structure to cover the roughened surface of the Ni wire to maximize the effective surface area. Thus, a specific capacitance, energy density, and power density of 14.4 F/cm3, 2 mWh/cm3, and 0.1 W/cm3, respectively, was obtained via single-electrode experiments. A fiber-shaped supercapacitor was prepared by twisting two electrodes with solid electrolytes made of KOH and polyvinyl alcohol. Although the solid electrolyte had a low ionic conductivity, the energy density and power density were determined to be 0.97 mWh/cm3 and 49.8 mW/cm3, respectively.

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