scholarly journals Ultralight, High Capacitance, Mechanically Strong Graphene-Cellulose Aerogels

Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 4891
Author(s):  
Xiuya Wang ◽  
Ke Wan ◽  
Pengbo Xie ◽  
Yuanyuan Miao ◽  
Zhenbo Liu
Keyword(s):  
Mechanical Properties ◽  
Specific Capacitance ◽  
Energy Demand ◽  
High Surface ◽  
High Surface Area ◽  
High Specific Capacitance ◽  
High Capacitance ◽  
Electrochemical Tests ◽  
Composite Aerogels ◽  
One Step

With increasing energy demand driving the need for eco-friendly and efficient energy storage technology, supercapacitors are becoming increasingly prevalent in wearable devices because of their portability and stability. The performance of these supercapacitors is highly dependent on the choice of electrode material. The high capacitance and mechanical properties needed for these materials can be achieved by combining graphene’s stable electrical properties with renewable cellulose’s excellent mechanical properties into porous aerogels. In this study, graphene-cellulose hydrogels were prepared by a one-step hydrothermal method, with porous, ultra-light, and mechanically strong graphene-cellulose aerogels then prepared by freeze-drying. These composite aerogels possess excellent mechanical strength and high specific capacitance, capable of bearing about 1095 times the pressure of their own weight. Electrochemical tests show the specific capacitance of these composite aerogels can reach 202 F/g at a scanning rate of 5 mA/cm2. In view of their high surface area and fast charge transport provided by their 3D porous structure, graphene-cellulose aerogels have great potential as sustainable supercapacitor electrodes.

Polyaniline based charcoal/Ni nanocomposite material for high performance supercapacitors

2018 ◽  
Vol 2 (4) ◽  
pp. 811-819 ◽  
Author(s):  
E. Elanthamilan ◽  
A. Sathiyan ◽  
S. Rajkumar ◽  
E. Joan Sheryl ◽  
J. Princy Merlin
Keyword(s):  
Specific Capacitance ◽  
Surface Area ◽  
High Performance ◽  
High Surface ◽  
High Surface Area ◽  
High Specific Capacitance ◽  
Nanocomposite Material

Among the synthesized PANI, PANI/AC, and PANI/AC/Ni nanomaterials, PANI/AC/Ni exhibits high specific capacitance (Cs) due to its high surface area.

Preparation and Electrochemical Characterization of an Activated Carbon Material of High Surface Area for Supercapacitor

2012 ◽  
Vol 463-464 ◽  
pp. 410-414 ◽  
Author(s):  
Jing Li ◽  
Xiao Dong Zhao
Keyword(s):  
Activated Carbon ◽  
Specific Capacitance ◽  
Surface Area ◽  
Carbon Material ◽  
Chemical Activation ◽  
High Surface ◽  
High Surface Area ◽  
High Specific Capacitance ◽  
Carbon Electrode ◽  
Equivalent Series Resistance

A low-cost organic compound mainly comprising of polyarylate was selected as precursor and a chemical activation method was used to prepare an activated carbon material of large surface area, with which the activated carbon electrodes of high specific capacitance were fabricated for supercapacitor. Impact of activating temperature on the specific capacitance of activated carbon electrode was studied, the relationship between the pore structure, surface area and specific capacitance of activated carbon electrode were discussed. The specific capacitance and ESR (equivalent series resistance ) of the electrode fabricated with the activated carbon prepared at 700°C is 211F.g-1 and 0.2Ω/cm2 in hydrous electrolyte and the 122F/g and 1Ω/cm2 in orgnic electrolyte respectively. Because of the different ion diameter in orgnic and hydrous electrolyte, activated electrode show different electrochemical behavior in cyclic voltammetry examinations.

scholarly journals A New Approach of Fabricating Graphene Nanoplates@Natural Rubber Latex Composite and Its Characteristics and Mechanical Properties

2018 ◽  
Vol 4 (3) ◽  
pp. 50 ◽  
Author(s):  
Duong La ◽  
Tuan Nguyen ◽  
Viet Quoc ◽  
Tham Nguyen ◽  
Duy Nguyen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Natural Rubber ◽  
High Surface ◽  
High Surface Area ◽  
Natural Rubber Latex ◽  
Chemical Exfoliation ◽  
Rubber Composite ◽  
One Step ◽  
Mixing Method ◽  
Graphene Nanoplates

Graphene has been demonstrated to be one of the most promising candidates to use as filler to improve the electrical, thermal, chemical and mechanical properties of natural rubber due to exceptional high surface area, superior electrical and thermal conductivity, and remarkable gas impermeability resistance. In this study, graphene nanoplates (GNPs) were mass-produced by a one-step chemical exfoliation of natural graphite and used as a filler for the fabrication of GNPs@natural rubber composite by a simple mixing method. The resultant GNPs/rubber composite was characterized by using scanning electron microscopy (SEM), and a rheometer. The prepared graphene nanoplates had a thickness of less than 10 nm and a lateral size of tens of microns. The GNPs@rubber composite revealed an exceptional improvement of abrasion loss up to seven to ten fold, along with an approximately 400%, 200% and 30% increment of elongation at break, tear strength and tensile strength, respectively. Other mechanical properties, such as hardness, compression set and rebound, as well as the effect of the GNPs loadings on the mechanical properties of the composite, were also investigated in detail.

Efficient Preparation of Spongy-Like Porous-Activated Carbon from Waste Millfeed Towards High Performance Supercapacitors

NANO ◽  
2020 ◽  
Vol 15 (08) ◽  
pp. 2050106
Author(s):  
Rong-Rong Han ◽  
Hao-Yan Zhu ◽  
Min-Peng Li ◽  
Wen-Tong Yang ◽  
Chun Lu ◽  
...  
Keyword(s):  
Ionic Liquids ◽  
Activated Carbon ◽  
Specific Capacitance ◽  
Surface Area ◽  
Current Density ◽  
High Surface ◽  
High Surface Area ◽  
High Specific Capacitance ◽  
A Current ◽  
Porous Activated Carbon

Biomass-based activated porous carbon (PC) with large porosity and high surface area has been considered as potential electrode material for supercapacitors. The spongy-like porous-activated carbon (SPAC) was prepared from millfeed by one-step carbonization/activation with KOH treatment. It shows three-dimensional (3D) spongy-like structure and high specific surface area (1535[Formula: see text]m2[Formula: see text]g[Formula: see text]). The SPAC electrode exhibits a high specific capacitance (237.9[Formula: see text]F[Formula: see text]g[Formula: see text] at a current density of 0.5[Formula: see text]A[Formula: see text]g[Formula: see text]) and a superior cycle stability (the capacitance retention of 95% after 10[Formula: see text]000 cycles at 2[Formula: see text]A[Formula: see text]g[Formula: see text]) in 2[Formula: see text]M KOH electrolyte, while the SPAC reveals a high specific capacitance of 157[Formula: see text]F[Formula: see text]g[Formula: see text] at 0.5[Formula: see text]A[Formula: see text]g[Formula: see text], good electrochemical stability with 93% capacitance retention after 5000 cycles in ionic liquids. Furthermore, the specific capacitance of SPAC//SPAC supercapacitor reaches 82.1[Formula: see text]F[Formula: see text]g[Formula: see text] at a current density of 0.5[Formula: see text]A[Formula: see text]g[Formula: see text] and achieves a high capacitance retention of 75% when the charging current increases to 10[Formula: see text]A[Formula: see text]g[Formula: see text] in 2[Formula: see text]M KOH electrolyte. The SPAC//SPAC supercapacitor possesses a high specific capacitance of 29.6[Formula: see text]F[Formula: see text]g[Formula: see text] at 0.5[Formula: see text]A[Formula: see text]g[Formula: see text] and a preeminent energy density of 27.8[Formula: see text]Wh[Formula: see text]kg[Formula: see text] (at a power density of 640[Formula: see text]W[Formula: see text]kg[Formula: see text]) in ionic liquids. This paper provides a convenient approach to synthesize low-cost biomass-based carbon material for supercapacitor applications.

scholarly journals Mechanical Properties of Hybrid Graphene Nanoplatelet-Nanosilica Filled Unidirectional Basalt Fibre Composites

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1468
Author(s):  
Ummu Raihanah Hashim ◽  
Aidah Jumahat ◽  
Mohammad Jawaid
Keyword(s):  
Mechanical Properties ◽  
Polymer Composites ◽  
Glass Fibre ◽  
Graphene Nanosheets ◽  
High Surface ◽  
High Surface Area ◽  
High Strength ◽  
Basalt Fibre ◽  
Graphene Nanoplatelet ◽  
Dispersion State

Basalt fibre (BF) is one of the most promising reinforcing natural materials for polymer composites that could replace the usage of glass fibre due to its comparable properties. The aim of adding nanofiller in polymer composites is to enhance the mechanical properties of the composites. In theory, the incorporation of high strength and stiffness nanofiller, namely graphene nanoplatelet (GNP), could create superior composite properties. However, the main challenges of incorporating this nanofiller are its poor dispersion state and aggregation in epoxy due to its high surface area and strong Van der Waals forces in between graphene sheets. In this study, we used one of the effective methods of functionalization to improve graphene’s dispersion and also introducing nanosilica filler to enhance platelets shear mechanism. The high dispersive silica nanospheres were introduced in the tactoids morphology of stacked graphene nanosheets in order to produce high shear forces during milling and exfoliate the GNP. The hybrid nanofiller modified epoxy polymers were impregnated into BF to evaluate the mechanical properties of the basalt fibre reinforced polymeric (BFRP) system under tensile, compression, flexural, and drop-weight impact tests. In response to the synergistic effect of zero-dimensional nanosilica and two-dimensional graphene nanoplatelets enhanced the mechanical properties of BFRP, especially in Basalt fibre + 0.2 wt% GNP/15 wt% NS (BF-H0.2) with the highest increment in modulus and strength to compare with unmodified BF. These findings also revealed that the incorporation of hybrid nanofiller contributed to the improvement in the mechanical properties of the composite. BF has huge potential as an alternative to the synthetic glass fibre for the fabrication of mechanical components and structures.

scholarly journals Glucose/Graphene-Based Aerogels for Gas Adsorption and Electric Double Layer Capacitors

Polymers ◽  
2018 ◽  
Vol 11 (1) ◽  
pp. 40 ◽  
Author(s):  
Kang-Kai Liu ◽  
Biao Jin ◽  
Long-Yue Meng
Keyword(s):  
Gas Adsorption ◽  
High Surface ◽  
Aqueous Media ◽  
High Surface Area ◽  
Three Dimensional ◽  
High Specific Capacitance ◽  
Mesopore Size Distribution ◽  
Excellent Electrochemical Performance ◽  
Double Layer Capacitors ◽  
Hydrothermal Reduction

In this study, three-dimensional glucose/graphene-based aerogels (G/GAs) were synthesized using the hydrothermal reduction and CO2 activation method. Graphene oxide (GO) was used as a matrix, and glucose was used as a binder for the orientation of the GO morphology in an aqueous media. We determined that G/GAs exhibited narrow mesopore size distribution, a high surface area (763 m2 g−1), and hierarchical macroporous and mesoporous structures. These features contributed to G/GAs being promising adsorbents for the removal of CO2 (76.5 mg g−1 at 298 K), CH4 (16.8 mg g−1 at 298 K), and H2 (12.1 mg g−1 at 77 K). G/GAs presented excellent electrochemical performance, featuring a high specific capacitance of 305.5 F g−1 at 1 A g−1, and good cyclic stability of 98.5% retention after 10,000 consecutive charge-discharge cycles at 10 A g−1. This study provided an efficient approach for preparing graphene aerogels exhibiting hierarchical porosity for gas adsorption and supercapacitors.

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.

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