scholarly journals Liquid Phase Synthesis of CoP Nanoparticles with High Electrical Conductivity for Advanced Energy Storage

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Guo-Qun Zhang ◽  
Bo Li ◽  
Mao-Cheng Liu ◽  
Shang-Ke Yuan ◽  
Leng-Yuan Niu
Keyword(s):  
Electrical Conductivity ◽  
Energy Storage ◽  
Liquid Phase ◽  
Specific Capacitance ◽  
Current Density ◽  
High Surface ◽  
High Surface Area ◽  
High Energy ◽  
High Energy Density ◽  
Energy Storage Materials

Transition metal phosphide alloys possess the metalloid characteristics and superior electrical conductivity and are a kind of high electrical conductive pseudocapacitive materials. Herein, high electrical conductive cobalt phosphide alloys are fabricated through a liquid phase process and a nanoparticles structure with high surface area is obtained. The highest specific capacitance of 286 F g−1 is reached at a current density of 0.5 A g−1. 63.4% of the specific capacitance is retained when the current density increased 16 times and 98.5% of the specific capacitance is maintained after 5000 cycles. The AC//CoP asymmetric supercapacitor also shows a high energy density (21.3 Wh kg−1) and excellent stability (97.8% of the specific capacitance is retained after 5000 cycles). The study provides a new strategy for the construction of high-performance energy storage materials by enhancing their intrinsic electrical conductivity.

scholarly journals Vertical Graphenes Grown on a Flexible Graphite Paper as an All-Carbon Current Collector towards Stable Li Deposition

Research ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-11 ◽  
Author(s):  
Zhijia Huang ◽  
Debin Kong ◽  
Yunbo Zhang ◽  
Yaqian Deng ◽  
Guangmin Zhou ◽  
...  
Keyword(s):  
Current Density ◽  
Rational Design ◽  
High Surface ◽  
High Surface Area ◽  
Current Collector ◽  
Cycling Performance ◽  
High Energy ◽  
High Energy Density ◽  
Uniform Electric Field ◽  
Metal Anode

Lithium (Li) metal has been regarded as one of the most promising anode materials to meet the urgent requirements for the next-generation high-energy density batteries. However, the practical use of lithium metal anode is hindered by the uncontrolled growth of Li dendrites, resulting in poor cycling stability and severe safety issues. Herein, vertical graphene (VG) film grown on graphite paper (GP) as an all-carbon current collector was utilized to regulate the uniform Li nucleation and suppress the growth of dendrites. The high surface area VG grown on GP not only reduces the local current density to the uniform electric field but also allows fast ion transport to homogenize the ion gradients, thus regulating the Li deposition to suppress the dendrite growth. The Li deposition can be further guided with the lithiation reaction between graphite paper and Li metal, which helps to increase lithiophilicity and reduce the Li nucleation barrier as well as the overpotential. As a result, the VG film-based anode demonstrates a stable cycling performance at a current density higher than 5 mA cm-2 in half cells and a small hysteresis of 50 mV at 1 mA cm-2 in symmetric cells. This work provides an efficient strategy for the rational design of highly stable Li metal anodes.

scholarly journals Titanium carbide MXene: Synthesis, electrical and optical properties and their applications in sensors and energy storage devices

2019 ◽  
Vol 9 ◽  
pp. 184798041882447 ◽  
Author(s):  
Johnson Michael ◽  
Zhang Qifeng ◽  
Wang Danling
Keyword(s):  
Energy Storage ◽  
Electrical Properties ◽  
Titanium Carbide ◽  
Inorganic Compounds ◽  
High Surface ◽  
High Surface Area ◽  
Volume Ratio ◽  
Energy Storage Materials ◽  
Post Processing ◽  
Energy Storage Devices

MXenes have been under a lot of scientific investigation due to the novel characteristics that are inherent to two-dimensional nanostructures. There are a multitude of MXenes being studied and one of the most popular among these would be the titanium carbides. The general formula for titanium carbide is Ti n+ 1C n for the nanosheets produced that have undergone much study in the past few years. These studies include how the etching process affects the final MXene sheet and how the post-processing via heat or combining with polymers and/or inorganic compounds influences the mechanical and electrical properties. It is found that different etching techniques can be used to change the electrical properties of the produced MXenes and different post-processing techniques can be used to further change the properties of the nanosheets. The possible application of the titanium carbide MXenes as chemical sensing and energy storage materials will be briefly discussed. MXene nanosheets show promise in such devices due to their high surface area to volume ratio and their specific surface structure with feasible surface functionalization.

scholarly journals A Minimal Volume Hermetic Packaging Design for High-Energy-Density Micro-Energy Systems

Energies ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2492
Author(s):  
Xiujun Yue ◽  
Jessica Grzyb ◽  
Akaash Padmanabha ◽  
James H. Pikul
Keyword(s):  
Energy Storage ◽  
Energy Density ◽  
Energy Systems ◽  
High Energy ◽  
High Energy Density ◽  
Energy Storage Materials ◽  
Current Collectors ◽  
Minimal Volume ◽  
Hermetic Packaging ◽  
Packaging Strategy

Hermetic packaging is critical to the function of many microscale energy storage and harvesting devices. State-of-the-art hermetic packaging strategies for energy technologies, however, are designed for macroscale devices and dramatically decrease the fraction of active materials when applied to micro-energy systems. We demonstrated a minimal volume hermetic packaging strategy for micro-energy systems that increased the volume of active energy storage materials by 2× and 5× compared to the best lab scale microbatteries and commercial pouch cells. The minimal volume design used metal current collectors as a multifunctional hermetic shell and laser-machined hot melt tape to provide a thin, robust hermetic seal between the current collectors with a stronger adhesion to metals than most commercial adhesives. We developed the packaging using commercially available equipment and materials, and demonstrated a strategy that could be applied to many kinds of micro-energy systems with custom shape configurations. This minimal, versatile packaging has the potential to improve the energy density of current micro-energy systems for applications ranging from biomedical devices to micro-robots.

Emerging NiCo2O4 Electrode Materials Assembled by Nanosheets for High Performance Hybrid Capacitor with High Specific Capacitance

2020 ◽  
Vol 15 (4) ◽  
pp. 498-503
Author(s):  
Jian Wang ◽  
Yan Zhao ◽  
Dong Zhang ◽  
Yucai Li ◽  
Shiwei Song ◽  
...  
Keyword(s):  
Energy Storage ◽  
Specific Capacitance ◽  
Power Density ◽  
Rational Design ◽  
Electrode Materials ◽  
High Specific Capacitance ◽  
High Energy ◽  
High Energy Density ◽  
Storage Device ◽  
Energy Storage Devices

Rational design and construction of hybrid capacitor electrode materials with prominent energy and power density plays an indispensable role for its potential application in energy storage devices. In this work, the nanoflower-like NiCo2O4 samples are successfully prepared on Ni foam via a facile hydrothermal method. The as-fabricated NiCo2O4 samples exhibit superior electrochemical performance with a high specific capacitance of 444.4 F g–1 at 1 A g–1 and excellent capacitance retention. In addition, the as-fabricated device presents a high energy density of 0.298 mWh cm–3 at a power density of 5.71 mW cm–3 and excellent cycle stability with the capacitance retention of 75.6% after 10000 cycles, indicating a promising application as electrodes for energy storage device.

scholarly journals Strongly Anchoring Polysulfides by Hierarchical Fe3O4/C3N4 Nanostructures for Advanced Lithium–Sulfur Batteries

2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Soochan Kim ◽  
Simindokht Shirvani-Arani ◽  
Sungsik Choi ◽  
Misuk Cho ◽  
Youngkwan Lee
Keyword(s):  
High Surface ◽  
Specific Capacity ◽  
High Surface Area ◽  
High Energy ◽  
High Energy Density ◽  
Energy Storage Devices ◽  
Shuttle Effect ◽  
Practical Applications ◽  
Storage Devices ◽  
Lithium Sulfur Batteries

AbstractLi–S batteries have attracted considerable interest as next-generation energy storage devices owing to high energy density and the natural abundance of sulfur. However, the practical applications of Li–S batteries are hampered by the shuttle effect of soluble lithium polysulfides (LPS), which results in low cycle stability. Herein, a functional interlayer has been developed to efficiently regulate the LPS and enhance the sulfur utilization using hierarchical nanostructure of C3N4 (t-C3N4) embedded with Fe3O4 nanospheres. t-C3N4 exhibits high surface area and strong anchoring of LPS, and the Fe3O4/t-C3N4 accelerates the anchoring of LPS and improves the electronic pathways. The combination of these materials leads to remarkable battery performance with 400% improvement in a specific capacity and a low capacity decay per cycle of 0.02% at 2 C over 1000 cycles, and stable cycling at 6.4 mg cm−2 for high-sulfur-loading cathode.

scholarly journals Simple CVD growth of P-doped graphitic hallow carbon spheres for high-voltage (2.0 V) aqueous symmetric supercapacitor

2021 ◽  
Author(s):  
Karthikeyan Gunasekaran Govindarasu ◽  
Boopathi Ganesan ◽  
Ramani Venkatesan ◽  
Pandurangan Arumugam
Keyword(s):  
High Performance ◽  
High Surface ◽  
High Surface Area ◽  
Mesoporous Structure ◽  
High Energy ◽  
High Energy Density ◽  
Carbon Spheres ◽  
Symmetric Supercapacitor ◽  
Red Led ◽  
Hollow Carbon

AbstractDoping of heteroatom into well-structured mesoporous carbon architecture can significantly augment the capacitive performance. In this work, we report P-doped graphitic hollow carbon spheres (P-GHCS) grown over Fe-KIT-6 through the in situ approach using the catalytic CVD technique. The obtained P-GHCS possesses a relatively high surface area with uniform mesoporous structure, good graphitization with tunable P-doping contents. The highly favorable structure and desirable heteroatom doping were taken into account to evaluate the P-GHCS as a modified electrode material towards high-performance supercapacitor. The optimized P-GHCS-800 sample exhibits superior specific capacitance (Csp) 321 F g−1 at 0.2 A g−1 with outstanding cycling stability with 2.9% loss of its initial capacitance after 2000 cycles in 6 M KOH electrolyte background in the three-electrode computerized system. More importantly, the fabricated P-GHCS-800 symmetric supercapacitor device can withstand at a wide potential width of 2.0 V, together with remarkable cyclic stability (89.09%) after 2000 cycles at a current density of 1 A g−1 in aqueous 1 M Na2SO4 as electrolyte providing a relatively high energy density of 10.83 Wh kg−1 with a power density of 222.78 W kg−1. Additionally, we demonstrated the single symmetric supercapacitor cell which provided sufficient energy to turn on a red LED of 20 mW and emit light over a certain period of time opens up possible realistic applications.

scholarly journals Capture and Methanation of CO2 Using Dual-Function Materials (DFMs)

2020 ◽  
Vol 2 (1) ◽  
pp. 35
Author(s):  
Anastasios I. Tsiotsias ◽  
Nikolaos D. Charisiou ◽  
Ioannis V. Yentekakis ◽  
Maria A. Goula
Keyword(s):  
Power Plants ◽  
Research Effort ◽  
High Surface ◽  
High Surface Area ◽  
High Energy ◽  
Metallic Phase ◽  
High Energy Density ◽  
Dual Function ◽  
Synthetic Natural Gas ◽  
Ch4 Production

The conversion of CO2, captured from flue gases, into synthetic natural gas (SNG) aims to create a closed carbon cycle, where excess H2 produced from renewables is utilized to transform CO2 released from existing conventional power plants into a reliable and high energy density carrier, that is CH4. In the last five years, extensive research effort has been dedicated to the synthesis and optimization of composite materials for the realization of this process. These materials, also known as dual-function materials or DFMs, typically consist of an alkaline metal oxide or carbonate phase, along with a Ru or Ni metallic phase supported on a high surface area carrier. The DFMs incorporate both sorptive and catalytic capabilities, capturing the CO2 in the initial sorption step and then converting it into CH4 upon H2 inflow. The dispersion of the sorptive and catalytically active phases, the CO2 affinity of the alkaline phase, the reducibility of the supported metals, and the selectivity towards CH4 production are some of the parameters influencing their performance. Hereby, we aim to present the most recent works dedicated to the development and optimization of such dual-function materials to be used in the combined capture and methanation of CO2.

scholarly journals One-Step Hydrothermal Synthesis of a CoTe@rGO Electrode Material for Supercapacitors

2021 ◽  
Author(s):  
Tianrui Wang ◽  
Yupeng Su ◽  
Mi Xiao ◽  
Meilian Zhao ◽  
Tingwu Zhao ◽  
...  
Keyword(s):  
Energy Density ◽  
Specific Capacitance ◽  
Power Density ◽  
Current Density ◽  
Electrode Material ◽  
High Energy ◽  
Cycling Stability ◽  
High Energy Density ◽  
One Step ◽  
Charge Discharge

AbstractCoTe@reduced graphene oxide (CoTe@rGO) electrode materials for supercapacitors were prepared by a one-step hydrothermal method in this paper. Compared with that of pure CoTe, the electrochemical performance of CoTe@rGO was significantly improved. The results showed that the optimal CoTe@rGO electrode material has a remarkably high specific capacitance of 810.6 F/g at a current density of 1 A/g. At 5 A/g, the synthesized material retained 77.2% of its initial capacitance even after 5000 charge/discharge cycles, thereby demonstrating good cycling stability. Moreover, even at a high current density of 20 A/g, the composite electrode retained 79.0% of its specific capacitance at 1 A/g, thus confirming its excellent rate performance. An asymmetric supercapacitor (ASC) with a wider potential window and higher energy density was assembled by using 3 M KOH as the electrolyte, the CoTe@rGO electrode as the positive electrode, and active carbon as the negative electrode. The operating voltage of the supercapacitor could be increased to 1.6 V, and its specific capacitance could reach 112.6 F/g at 1 A/g. The specific capacitance retention rate of the fabricated supercapacitor after 5000 charge/discharge cycles at 5 A/g was 87.1%, which confirms its excellent cycling stability. In addition, the ASC revealed a high energy density of 40.04 W·h/kg at a power density of 799.91 W/kg and a high power density of 4004.93 W/kg at an energy density of 33.43 W·h/kg. These results collectively show that CoTe@rGO materials have broad application prospects.

scholarly journals Nitrogen self-doped activated carbons via the direct activation of Samanea saman leaves for high energy density supercapacitors

RSC Advances ◽  
2019 ◽  
Vol 9 (38) ◽  
pp. 21724-21732 ◽  
Author(s):  
Vichuda Sattayarut ◽  
Thanthamrong Wanchaem ◽  
Pundita Ukkakimapan ◽  
Visittapong Yordsri ◽  
Paweena Dulyaseree ◽  
...  
Keyword(s):  
Energy Density ◽  
Surface Area ◽  
Activated Carbons ◽  
High Surface ◽  
High Surface Area ◽  
High Energy ◽  
High Energy Density ◽  
Direct Activation ◽  
Samanea Saman

Nitrogen self-doped activated carbons with high surface area obtained via the direct activation of Samanea saman leaves for high energy density supercapacitors.

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