Electrochemical Charge Storage Performance of Mesoporous MoO3@Co3O4 Nanocomposites as Electrode Materials

2021 ◽  
Author(s):  
Dillip Kumar Mohapatra ◽  
Swetapadma Praharaj ◽  
Dibyaranjan Rout
Keyword(s):  
Redox Reactions ◽  
High Performance ◽  
Electrode Materials ◽  
Coulombic Efficiency ◽  
Average Pore Size ◽  
Electrochemical Capacitors ◽  
Bet Surface Area ◽  
Average Pore ◽  
Storage Performance ◽  
Reversible Redox

Abstract Constructing a novel nanocomposite structure based on Co3O4 is of the current interest to design and develop efficient electrochemical capacitors. The capacitive performance of MoO3@Co3O4 nanocomposite is compared with pristine Co3O4 nanoparticles, both of them being synthesized by hydrothermal technique. A BET surface area of ~41 m2g-1 (almost twice that of Co3O4 )and average pore size of 3.6 nm is found to be suitable for promoting Faradaic reactions in the nanocomposite. Electrochemical measurements conducted on both samples predict capacitive behavior with quasi-reversible redox reactions. MoO3@Co3O4 nanocomposite is capable of delivering a superior specific capacitance of 1248 Fg-1 at 0.5 Ag-1 along with notable stability of 92% even after 2000 cycles of charge-discharge and Coulombic efficiency approaching 100% at 10 Ag-1. The outstanding results obtained in this work assure functional adequacy of MoO3@Co3O4 nanocomposite in fabricating high-performance electrochemical capacitors.

scholarly journals Preparation of High-Performance Activated Carbon from Coffee Grounds after Extraction of Bio-Oil

Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 257
Author(s):  
Jie Ren ◽  
Nanwei Chen ◽  
Li Wan ◽  
Guojian Li ◽  
Tao Chen ◽  
...  
Keyword(s):  
Activated Carbon ◽  
High Performance ◽  
Average Pore Size ◽  
Total Pore Volume ◽  
Micropore Volume ◽  
Bet Surface Area ◽  
Average Pore ◽  
Activation Temperature ◽  
Coffee Grounds ◽  
Bio Oil

In this study, a new method for economical utilization of coffee grounds was developed and tested. The resulting materials were characterized by proximate and elemental analyses, thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and N2 adsorption–desorption at 77 K. The experimental data show bio-oil yields reaching 42.3%. The optimal activated carbon was obtained under vacuum pyrolysis self-activation at an operating temperature of 450 °C, an activation temperature of 600 °C, an activation time of 30 min, and an impregnation ratio with phosphoric acid of 150 wt.%. Under these conditions, the yield of activated carbon reached 27.4% with a BET surface area of 1420 m2·g−1, an average pore size of 2.1 nm, a total pore volume of 0.747 cm3·g−1, and a t-Plot micropore volume of 0.428 cm3·g−1. In addition, the surface of activated carbon looked relatively rough, containing mesopores and micropores with large amounts of corrosion pits.

scholarly journals Strategies for improving the lithium-storage performance of 2D nanomaterials

2017 ◽  
Vol 5 (3) ◽  
pp. 389-416 ◽  
Author(s):  
Jun Mei ◽  
Yuanwen Zhang ◽  
Ting Liao ◽  
Ziqi Sun ◽  
Shi Xue Dou
Keyword(s):  
Transition Metal ◽  
High Performance ◽  
Electrode Materials ◽  
Coulombic Efficiency ◽  
Lithium Ion ◽  
Clean Energy ◽  
Transition Metal Dichalcogenide ◽  
Lithium Storage ◽  
Storage Performance ◽  
2D Nanomaterials

Abstract 2D nanomaterials, including graphene, transition metal oxide (TMO) nanosheets, transition metal dichalcogenide (TMD) nanosheets, etc., have offered an appealing and unprecedented opportunity for the development of high-performance electrode materials for lithium-ion batteries (LIBs). Although significant progress has been made on 2D nanomaterials for LIB applications in the recent years, some major challenges still exist for the direct use of these sheet-like nanomaterials, such as their serious self-agglomerating tendency during electrode fabrication and low conductivity as well as the large volume changes over repeated charging–discharging cycles for most TMOs/TMDs, which have resulted in large irreversible capacity, low initial Coulombic efficiency and fast capacity fading. To address these issues, considerable progress has been made in the exploitation of 2D nanosheets for enhanced lithium storage. In this review, we intend to summarize the recent progress on the strategies for enhancing the lithium-storage performance of 2D nanomaterials, including hybridization with conductive materials, surface/edge functionalization and structural optimization. These strategies for manipulating the structures and properties of 2D nanomaterials are expected to meet the grand challenges for advanced nanomaterials in clean energy applications and thus provide access to exciting materials for achieving high-performance next-generation energy-storage devices.

Biomass-derived interconnected carbon nanoring electrochemical capacitors with high performance in both strongly acidic and alkaline electrolytes

2017 ◽  
Vol 5 (1) ◽  
pp. 181-188 ◽  
Author(s):  
Xianjun Wei ◽  
Yongbin Li ◽  
Shuyan Gao
Keyword(s):  
High Performance ◽  
Electrode Materials ◽  
Electrochemical Capacitors ◽  
High Rate ◽  
Alkaline Electrolytes

The match between sustainable electrode materials and electrolytes is the key to achieve high-rate electrochemical capacitors.

scholarly journals High-capacity rechargeable batteries based on deeply cyclable lithium metal anodes

2018 ◽  
Vol 115 (22) ◽  
pp. 5676-5680 ◽  
Author(s):  
Qiuwei Shi ◽  
Yiren Zhong ◽  
Min Wu ◽  
Hongzhi Wang ◽  
Hailiang Wang
Keyword(s):  
High Performance ◽  
Electrode Materials ◽  
Coulombic Efficiency ◽  
High Capacity ◽  
Protective Layer ◽  
Rechargeable Batteries ◽  
Metal Electrodes ◽  
Lithium Metal Anodes ◽  
Low Efficiency ◽  
Almost All

Discovering new chemistry and materials to enable rechargeable batteries with higher capacity and energy density is of paramount importance. While Li metal is the ultimate choice of a battery anode, its low efficiency is still yet to be overcome. Many strategies have been developed to improve the reversibility and cycle life of Li metal electrodes. However, almost all of the results are limited to shallow cycling conditions (e.g., 1 mAh cm−2) and thus inefficient utilization (<1%). Here we achieve Li metal electrodes that can be deeply cycled at high capacities of 10 and 20 mAh cm−2 with average Coulombic efficiency >98% in a commercial LiPF6/carbonate electrolyte. The high performance is enabled by slow release of LiNO3 into the electrolyte and its subsequent decomposition to form a Li3N and lithium oxynitrides (LiNxOy)-containing protective layer which renders reversible, dendrite-free, and highly dense Li metal deposition. Using the developed Li metal electrodes, we construct a Li-MoS3 full cell with the anode and cathode materials in a close-to-stoichiometric amount ratio. In terms of both capacity and energy, normalized to either the electrode area or the total mass of the electrode materials, our cell significantly outperforms other laboratory-scale battery cells as well as the state-of-the-art Li ion batteries on the market.

Quinone/hydroquinone redox couple as a source of enormous capacitance of activated carbon electrodes

2013 ◽  
Vol 1505 ◽  
Author(s):  
Krzysztof Fic ◽  
Mikolaj Meller ◽  
Grzegorz Lota ◽  
Elzbieta Frackowiak
Keyword(s):  
Activated Carbon ◽  
Redox Reactions ◽  
Electrode Materials ◽  
Activated Carbons ◽  
Hydroxyl Group ◽  
Carbon Surface ◽  
Carbon Electrodes ◽  
Main Subject ◽  
Solution Ph ◽  
Reversible Redox

ABSTRACTThe main subject of this paper is to examine and to evaluate the capacitive behaviour of activated carbon electrodes electrochemically decorated by quinone-type functional groups. For this purpose, different electrolytes, i.e. hydroquinone, catechol and resorcinol at the concentration of 0.38 mol L-1, dissolved in 1 mol L-1 H2SO4, 1 mol L-1 Li2SO4 and 6 mol L-1 KOH were used. These electrolytes could generate electroactive groups (able to undergo reversible redox reactions) on the surface of electrode material. Apart from typical adsorption of the mentioned dihydroxybenzenes, so called grafting could occur and might cause generation of quinone|hydroquinone functionals on carbon surface. As an effect of functional reversible redox reaction, additional capacitance value, called pseudocapacitance, could be achieved. Hence, besides typical charge originating from charging/discharging of the electrical double layer on the electrode/electrolyte interface, additional capacitance comes also from faradaic reactions. Activated carbons are the most promising electrode materials for this purpose; apart from great physicochemical properties, they are characterized by well-developed specific surface area over 2000 m2 g-1 which results in high capacitance values.In the manuscript the influence of the hydroxyl group location as well as electrolyte solution pH on the electrochemical performance of the electrode is discussed.

scholarly journals A Cryogenic Milling Method to Fabricate Nanostructured Anodes

2020 ◽  
Author(s):  
Qizhang Yan ◽  
Shu-Ting Ko ◽  
Yumin Zhao ◽  
Grace Whang ◽  
Andrew Dawson ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
High Performance ◽  
Electrode Materials ◽  
Coulombic Efficiency ◽  
Graphite Powder ◽  
Cryogenic Milling ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Battery Electrode ◽  
Milling Method

Cryogenic milling was demonstrated as a new and facile method to fabricate nanostructured battery electrode materials. SnSb anode material with 1.2 wt% graphite was selected as a model system to demonstrate the feasibility and benefits of this method. Ball milling at a cryogenic temperature can suppress cold welding, exfoliate bulk graphite powder into nanoplatelets, and evenly disperse them between the grains. Aberration-corrected scanning transmission electron microscopy and post-cycling scanning electron microscopy showed refined grain sizes and well-dispersed carbon nanoplatelets, which can stabilize the nanostructure and alleviate volume expansion and cracking upon cycling. The cryomilled SnSb-C composite anode showed a reversible volumetric capacity of 1842 Ah/L, average coulombic efficiency of 99.6 ± 0.3%, and capacity retention of 90% over 100 cycles. The cryomilled sample showed improved electrochemical performance compared to the conventional ball milled specimen. This new method of cryogenic milling can produce various other high-performance nanostructured electrode materials.

scholarly journals A Cryogenic Milling Method to Fabricate Nanostructured Anodes

2020 ◽  
Author(s):  
Qizhang Yan ◽  
Shu-Ting Ko ◽  
Yumin Zhao ◽  
Grace Whang ◽  
Andrew Dawson ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
High Performance ◽  
Electrode Materials ◽  
Coulombic Efficiency ◽  
Graphite Powder ◽  
Cryogenic Milling ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Battery Electrode ◽  
Milling Method

Cryogenic milling was demonstrated as a new and facile method to fabricate nanostructured battery electrode materials. SnSb anode material with 1.2 wt% graphite was selected as a model system to demonstrate the feasibility and benefits of this method. Ball milling at a cryogenic temperature can suppress cold welding, exfoliate bulk graphite powder into nanoplatelets, and evenly disperse them between the grains. Aberration-corrected scanning transmission electron microscopy and post-cycling scanning electron microscopy showed refined grain sizes and well-dispersed carbon nanoplatelets, which can stabilize the nanostructure and alleviate volume expansion and cracking upon cycling. The cryomilled SnSb-C composite anode showed a reversible volumetric capacity of 1842 Ah/L, average coulombic efficiency of 99.6 ± 0.3%, and capacity retention of 90% over 100 cycles. The cryomilled sample showed improved electrochemical performance compared to the conventional ball milled specimen. This new method of cryogenic milling can produce various other high-performance nanostructured electrode materials.

scholarly journals Production of Highly Porous Biochar Materials from Spent Mushroom Composts

Horticulturae ◽  
2022 ◽  
Vol 8 (1) ◽  
pp. 46
Author(s):  
Wen-Shing Chen ◽  
Wen-Tien Tsai ◽  
Yu-Quan Lin ◽  
Chi-Hung Tsai ◽  
Yao-Tsung Chang
Keyword(s):  
Surface Area ◽  
Agricultural Waste ◽  
Average Pore Size ◽  
Chemical Properties ◽  
Edible Mushroom ◽  
Bet Surface Area ◽  
Mushroom Compost ◽  
Average Pore ◽  
Spent Mushroom Compost ◽  
Pore Properties

The edible mushroom industry has grown significantly in recent years due to the dietary change and the demand for heathy food. However, the spent mushroom compost (SMC) will be produced in large quantities after the harvest, thus forming an agricultural waste requiring proper management other than dumping or burning. In this work, two types of SMCs with the cultivation of shiitake fungus (SF) and black fungus (BF) were converted into porous biochar products (a series of SMC-SF-BC and SMC-BF-BC) at higher pyrolysis temperatures (i.e., 400, 600 and 800 °C) based on their thermochemical characteristics, using thermogravimetric analysis (TGA). The pore and chemical properties of the resulting products, including surface area, pore volume, average pore size, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and Fourier Transform infrared spectroscopy (FTIR), were studied to correlate them with the most important process parameter. The results showed that the pore properties of the biochar products indicated a significant increase with the increase in the pyrolysis temperature from 400 to 600 °C. The data on the maximal Brunauer-Emmett-Teller (BET) surface area for the biochar products produced at 800 °C (i.e., SMC-SF-BC-800 and SMC-BF-BC-800) were found to be 312.5 and 280.9 m2/g, respectively. Based on the EDS and FTIR, plenty of oxygen-containing functional groups were found on the surface of the resulting biochar products.

scholarly journals Boosting High-Rate Zinc-Storage Performance by the Rational Design of Mn2O3 Nanoporous Architecture Cathode

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Danyang Feng ◽  
Tu-Nan Gao ◽  
Ling Zhang ◽  
Bingkun Guo ◽  
Shuyan Song ◽  
...  
Keyword(s):  
High Performance ◽  
Manganese Oxides ◽  
Rational Design ◽  
Electrode Materials ◽  
Specific Capacity ◽  
Rate Capability ◽  
High Rate ◽  
Pore Sizes ◽  
Storage Performance ◽  
Zinc Storage

AbstractManganese oxides are regarded as one of the most promising cathode materials in rechargeable aqueous Zn-ion batteries (ZIBs) because of the low price and high security. However, the practical application of Mn2O3 in ZIBs is still plagued by the low specific capacity and poor rate capability. Herein, highly crystalline Mn2O3 materials with interconnected mesostructures and controllable pore sizes are obtained via a ligand-assisted self-assembly process and used as high-performance electrode materials for reversible aqueous ZIBs. The coordination degree between Mn2+ and citric acid ligand plays a crucial role in the formation of the mesostructure, and the pore sizes can be easily tuned from 3.2 to 7.3 nm. Ascribed to the unique feature of nanoporous architectures, excellent zinc-storage performance can be achieved in ZIBs during charge/discharge processes. The Mn2O3 electrode exhibits high reversible capacity (233 mAh g−1 at 0.3 A g−1), superior rate capability (162 mAh g−1 retains at 3.08 A g−1) and remarkable cycling durability over 3000 cycles at a high current rate of 3.08 A g−1. Moreover, the corresponding electrode reaction mechanism is studied in depth according to a series of analytical methods. These results suggest that rational design of the nanoporous architecture for electrode materials can effectively improve the battery performance. "Image missing"

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