JOURNAL OF POWER SOURCES
·
2020
·
IF 8.247
Zhengjiong Li,Haonan Peng,Rurong Liu,Yan Mo,Bokai Cao,Wende Lai,Xiran Li,Lisha Pan,Yong Chen
Activated carbon is widely used as electrode materials in supercapacitors , and its capacitive performance is significantly influenced by the specific surface area. However, different types of wall surfaces, such as basal-, edge- and defect-surfaces, exist in carbonaceous materials due to the complex structure and atomic distribution of carbon atoms, rendering different influences on capacitive charge storage behavior. Therefore, it is of utmost significance to quantitatively determine their contribution to the capacitive performance. Herein, the commercial graphite powder is ball milled to introduce different types of edges and defects, resulting in different proportions of basal-, edge- and defect-surfaces. Moreover, a modified non-local density functional theory calculations method is adopted to quantitatively evaluate the basal-, edge- and defect-surface area. Then, a relationship is established between the electrode capacitance and wall surface area by the linear regression method. The results reveal that the basal-, edge- and defect-surfaces contributed an areal capacitance of 0.04 μF cm −2 , 1.65 μF cm −2 and 7.95 μF cm −2 , respectively. Hence, the capacitance is mainly provided by the defects of wall surfaces.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
THIN SOLID FILMS
·
2018
·
IF 1.939
Kaili Yao,Bing Dai,Lei Yang,Guoyang Shu,Jiwen Zhao,Kang Liu,Wenxin Cao,Victor Ralchenko,Jiecai Han,Jiaqi Zhu
We report on high-quality microcrystalline diamond films deposited on Si substrates in microwave hydrogen plasma (without methane feed gas) using graphite powders with different sizes from 2 μm to 150 μm as the carbon source. Hydrocarbon radicals, necessary for diamond growth, are produced in course of the graphite etching by atomic hydrogen, and supplied into the plasma for further participation in diamond formation on the substrate. Owing to the large open surface area of the powder the approach allows a continuous long-term stable flux of hydrocarbons (as determined via in situ optical emission spectroscopy of the plasma) during the 10 h graphite etching process. The produced diamond films with grain size of ~1 μm were characterized with scanning electron microscopy and Raman spectroscopy , and exhibited similar morphology and crystallinity independent on the graphite powder dimensions.
研究领域:
材料科学
·
等离子体物理
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2019
·Vol. 137
·期 31
·48921
·
IF 2.188
Tai Zhang,Changfa Xiao,Jian Zhao,Xiaozhen Liu,Yan Huang,Dawei Ji
In this study, the cost-effective graphite powder (GPd)-coated polyurethane (PGPd-PU) sponge hollow tube (PGPd-PUHT) was prepared for high-efficient continuous oil removal, the hydrophobicity-superoleophilicity PGPd-PU sponge was fabricated through a simple dip-coating method, which dipping PU sponge into GPd dispersion and drying, then coating polydimethylsiloxane (PDMS) on sponge skeleton, as-prepared sponge could selectively absorb a variety of oils up to 34 times of its own weight for dimethyl sulfoxide (DMSO). The PGPd-PUHT was prepared via wrapping PGPd-PU sponge on porous tubular support. The obtained PGPd-PUHT could continuously collect various types of oils from water surface with flux as high as 1.52 kL/m 2 h, and excellent separation efficiency (up to 97.7%) for toluene, as well as remarkable reusability. Moreover, a continuous floating oil collection device based on PGPd-PUHT was designed which showed excellent floating oil collection ability. In addition, our strategy possesses the advantages of low cost, simple preparation, highly efficient, and easily scale-up, showing a great potential for dealing with practical oil spill remediation. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137 , 48921.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2014
·
IF 4.058
Xueli Wu,Jianhui Qiu,Peng Liu,Eiichi Sakai
Multi-walled carbon nanotube/polystyrene (MWCNT/PS), graphite powder/polystyrene (GP/PS) and multi-walled carbon nanotube–graphite powder/polystyrene (M–G/PS) nanocomposites with different contents of carbon materials were prepared by bulk radical polymerization. The products were pressed into slices to prepare specimens for electrical conductivity testing. All of the nanocomposites demonstrated good electrical conductivity. Compared to MWCNTs/PS and GP/PS composites, the M–G/PS composites showed a good synergistic effect between the MWCNTs and GP, and the electrical conductivity of M–G/PS was higher than that of GP/PS. To investigate the structure and morphology of the grafted carbon nano-materials, samples were submitted to Fourier transform infrared spectroscopy (FT-IR), thermal gravimetric analysis (TGA) and transmission electron microscopy (TEM) after being extracted with toluene. The results show that some polystyrene was grafted onto the surfaces of the MWCNTs, GP and M–G, which is likely responsible for the increase in the electrical conductivity of the composites. Furthermore, the mechanical properties of the M–G/PS nanocomposites increased with the M/G ratio.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Cleaner Production
·
2023
·
IF 11.1
Hongtao Li,Haitao Yang,Jiaxin Cheng,Qingshan Zhu
Electroless plating is the main method for preparing metal-coated composite powders , such as Ni-coated graphite powders with wide applications in electromagnetic shielding materials, sealing coating, and electrocatalysis. However, the issues of uniform and dense coating during synthesis are hindering its practical implementation. Incorporating noble metals, such as Pd, to activate powders is a typical technique to prepare an electroless Ni coating. However, noble metal utilization is hindered by issues such as high costs and substantial wastewater. Herein, a novel low-cost and eco-friendly activation method based on fluidized bed hydrogen reduction is designed to prepare densely coated Ni@irregular graphite particles (Ni@IGP) using a low Ni content. This method can be used to construct a uniform and dense Ni coating for composite powders without acid alkali treatment and use of precious metals during the overall manufacturing process . Results demonstrated that the Ni@IGP particle obtained through this approach have good electrical conductivity and ferromagnetic properties. In addition, the uniformity and integrity of the Ni plating were adjusted, and the dense coating of graphite at a low Ni content of 35 wt% was effectively achieved. This new activation method sheds light on the field of electroless Ni plating on powders.
研究领域:
材料科学
·
表面工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
LANGMUIR
·
2023
·
IF 3.9
Jing Mei,Zhian Qiu,Teng Gao,Qiang Wu,Fenghua Zheng,Juantao Jiang,Kui Liu,Youguo Huang,Hongqiang Wang,Qingyu Li
Electrochemical exfoliation starting with graphite powder as the raw material for graphene production shows superiority in cost effectiveness over the popular bulk graphite. However, the crucial conductive network inside the graphite powder electrode along with its formation and influence mechanisms remains blank. Here, an adjustable-pressure graphite powder electrode with a sandwich structure was designed for this. Appropriate encapsulation pressure is necessary and conducive to constructing a continuous and stable conductive network, but overloaded encapsulation pressure is detrimental to the exfoliation and graphene quality. With an initial encapsulation pressure (IEP) of 4 kPa, the graphite powders expand rapidly to a final stable expansion pressure of 49 kPa with a final graphene yield of 46.3%, where 84% of the graphene sheets are less than 4 layers with ID/IG values between 0.22 and 1.24. Increasing the IEP to 52 kPa, the expansion pressure increases to 73 kPa, but the graphene yield decreases to 39.3% with a worse graphene quality including higher layers and ID/IG values of 1.68–2.13. In addition, small-size graphite powders are not suitable for the electrochemical exfoliation. With the particle size decreasing from 50 to 325 mesh, the graphene yield decreases almost linearly from 46.3% to 5.5%. Conductive network and electrolyte migration synergize and constrain each other, codetermining the electrochemical exfoliation. Within an encapsulated structure, the electrochemical exfoliation of the graphite powder electrode proceeds from the outside to the inside. The insights revealed here will provide direction for further development of electrochemical exfoliation of graphite powder to produce graphene.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SOLAR ENERGY MATERIALS AND SOLAR CELLS
·
2018
·
IF 5.018
Fujun Tao,Yuliang Zhang,Binbin Wang,Fuhua Zhang,Xueting Chang,Runhua Fan,Lihua Dong,Yansheng Yin
Water evaporation, a promising and environmentally friendly technology driven by local hot spots on the water-air interface, is an efficient way to utilize solar energy. Herein, we present a novel laminar solar absorber consisting of graphite powder (GP) and a semipermeable collodion membrane (SCM) as an integrated structural system for highly efficient water evaporation. The GP/SCM composite can efficiently convert the absorbed solar energy to heat energy , e.g., the 8 mg-GP/SCM (i.e., the GP/SCM with 8 mg GP added) enables water evaporation with high efficiency of 56.8% under 1.5 kW/m 2 irradiation and 65.8% under 3 kW/m 2 irradiation, respectively. Cycling tests verify that the GP/SCM could retain stable water evaporation performance over 20 cycles under the same conditions. Contrast experiments show that the other carbon-containing solar-absorbers, such as acetylene black (AB) and graphene nanoplates (GNPs) in SCM, display relatively low evaporation efficiency of 41.4% and 36.7%, respectively, under the simulated solar irradiation with a light density of 1.5 kW/m 2 . The laminar GP/SCM composite obtained in our work is low-cost, easy-to-prepare, recyclable, and highly efficient in its photothermal performance, so that it distinctly contributes to water evaporation.
研究领域:
材料科学
·
环境科学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED THERMAL ENGINEERING
·
2022
·
IF 6.465
Zichen Wang,Changqing Du,Rui Qi,Yijin Wang
In order to ensure the normal operation of lithium-ion battery in any climate environment, it is necessary to explore the temperature dependence of lithium-ion battery performance, and adopt an effective and low energy thermal management system to maintain the temperature of lithium-ion battery within the normal operating temperature range. In this paper, the temperature dependence of heat generation behavior and charge–discharge performance of lithium-ion battery was studied, and the critical temperature of heat preservation and preheating process was determined. On this basis, graphite powder/paraffin composite phase change material and graphite powder/paraffin/nickel foam ternary composite phase change material with optimized composition were prepared. The thermal management experiment of large-capacity rectangular lithium iron phosphate battery covering the whole climatic range was carried out. The performance of the following thermal management modes was compared: air natural convection, paraffin, graphite powder/paraffin composite, graphite powder/paraffin/nickel foam ternary composite. The experiment showed that the necessary heat dissipation of lithium-ion battery was needed at 20℃ and 40℃ to avoid exceeding the upper limit of normal working temperature. The charge–discharge performance of lithium-ion battery was very sensitive to low temperature environment, especially the battery endurance and charge–discharge capacity. Both graphite powder/paraffin and graphite powder/paraffin/nickel foam composites can effectively control the surface temperature rise of lithium-ion battery, and keep the surface temperature above 0℃ for at least 40 min in the extremely cold environment of −20℃. They also had similar heating efficiency. However, the ternary composite had better temperature homogeneity in both the high temperature environment of 40℃ and the extremely cold environment of −20℃. The maximum temperature difference of ternary composite in the preheating process was 21.43% lower than that of binary composite.
研究领域:
材料科学
·
能源工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2023
·Vol. 58
·期 22
·9116-9129
·
IF 4.5
Mei Jing,Qiu Zhian,Gao Teng,Wu Qiang,Liu Kui,Huang Youguo,Zheng Fenghua,Jiang Juantao,Wang Hongqiang,Li Qingyu
Graphite powder as a raw material for the production of graphene by electrochemical exfoliation is superior to bulk graphite in terms of cost-effectiveness and manufacturing process. However, the current technology is still in its infancy and lacks preliminary systematic research. Therefore, there is a blank in the theoretical basis for process optimization and production regulation. Here, the effects of the main process parameters including graphite powder category, electric field driving force, electrolyte type, and corresponding concentration were systematically investigated on the electrochemical exfoliation and graphene quality. Expanded graphite powder with flake structure, regular graphite layer arrangement, and large graphite layer spacing is superior to natural flake graphite powder and artificial graphite powder for the electrochemical exfoliation to produce graphene. Sulfate ion with large ionic radius is best suitable for intercalation and subsequent expansion to obtain a high graphene yield and a low I D / I G in graphene in aqueous solution. For graphite powder as raw material, there exist optimal values for both electrolyte concentration and driving voltage for graphene production. A high graphene yield of 42.5% with low defect density ( I D / I G = 0.14–1.43) and oxygen content of 30.54% can be obtained using Na 2 SO 4 at a concentration of 0.1 M at a voltage of 10 V for 4 h. The process optimization and regulation and corresponding influencing mechanisms of process parameters revealed here will provide guidance for the further development of graphene production by electrochemical exfoliation of graphite powder.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Energy Storage
·
2023
·
IF 9.4
Zichen Wang,Changqing Du,Rui Qi,Yijin Wang
Phase change material has become a research hotspot in the field of passive thermal management for lithium-ion batteries due to its low price and high latent heat. However, the low thermal conductivity limits the thermal efficiency of thermal management system. In this paper, the graphite powders/paraffin binary composite with a superior ratio suitable for battery thermal management was prepared, and the ternary composite was obtained by introducing nickel foam. The temperature fields during melting were visually observed through thermal imaging, and the influence mechanism of graphite powders and nickel foam on the movement pattern of the phase transition interface was investigated through comparative experiments . The results showed that the addition of nickel foam significantly accelerated the pushing rate of the phase transition interface in the lower and middle regions. The temperature difference along the height direction of both paraffin and binary composite increased with the increase of distance from the heating surface, while that of ternary composite showed no significant correlation with the distance. At a distance of 75 mm from the heating surface, the maximum temperature difference along the height direction of the ternary composite was 47.58 % and 25.43 % lower than that of the paraffin and binary composite, respectively. This paper also discussed the recovery periods for the thermal storage capacity of phase change materials. The ternary composite was the fastest to recover its thermal storage capacity, with its recovery period being 22 % shorter than that of the other materials. It also exhibited the best temperature uniformity. Its maximum temperature difference was 28.77 % lower than that of the other materials.
研究领域:
材料科学
·
能源工程
✓ 已验证
DOI
高影响因子
RUSSIAN JOURNAL OF ELECTROCHEMISTRY
·
2021
·Vol. 57
·期 8
·852-857
·
IF 1.078
Ke Qu,Deng Miao,Tang Wei
Abstract Electrochemical energy storage system has been a promising focus to tackle with the current energy crisis problem. Polyaniline (PANI) has been an attractive electrode material in energy storage devices, owning unique and excellent developing prospects in the field of supercapacitors. In order to further improve its capacitive performance, composite materials of PANI blended with various carbon-based materials, metal oxides or metal sulfides are typically prepared. In this study, PANI-based ternary composite of PANI, molybdenum disulfide (MoS 2 ) and graphite powder (Gr) was prepared electrochemically to afford the PANI/MoS 2 /Gr-modified electrode materials. Cyclic voltammetry (CV), galvanostatic charge and discharge (GCD) and electrochemical impedance spectroscopy (EIS) methods were used to characterize and investigate the ternary composite’s supercapacitive performance. A high specific capacitance of 381.9 F/g was achieved under 1 A/g current density. When the applied current densities were increased from 1 to 8 A/g, a high specific capacitance of 322.0 F/g was still maintained, which corresponded to a good capacitance retention rate of 84.3%, showing the ternary composite’s excellent rate performance. The research results illustrated the great potential of the PANI/MoS 2 /Gr ternary composite as a promising supercapacitor energy storage material.
研究领域:
电化学
·
能源存储材料
·
材料科学
✓ 已验证
DOI
高影响因子
MICROCHEMICAL JOURNAL
·
2024
·
IF 4.9
Nourhan M. Amaar,Fathi S. Awad,Wael I. Mortada,A.B. Abdallah
An innovative imprinted electrochemical platform was designed for the first time to detect vericiguat (VER), a soluble guanylate cyclase stimulator, in real samples. The smart sensor was fabricated by mixing a molecularly imprinted polymer (MIP) with graphite powder, obtained from a broken battery, and multiwalled carbon nanotubes (MWCNT) in the presence of paraffin oil. Density functional theory (DFT) was utilized not only to predict promising monomers for the polymerization process but also to investigate the interaction between the selected monomers and the VER template. Highly interactive acrylamide and methyl methacrylate monomers were first employed to interact with the VER template; then, the initiator, 2,2′-azobisisobutyronitrile, and the cross linker, ethylene glycol dimethacrylate, were added. The resulting MIP was characterized using different techniques including Fourier transform infrared spectroscopy, atomic force microscopy, scanning electron microscopy, and elemental mapping. The electrochemical performance of the synthesized sensor was investigated using cyclic voltammetry and electrochemical impedance spectroscopy. Using differential pulse voltammetry, the fabricated imprinted sensor was successfully utilized to monitor VER with a low limit of detection of 1.68 × 10 −9 mol L −1 over a linear concentration range of 5.1 × 10 −9 mol L −1 –2.3 × 10 −4 mol L −1 , with a correlation coefficient of 0.98. In addition, it showed excellent selectivity in the presence of other coexisting molecules, high stability (32 days), and good reproducibility (RSD = 4.68 %) and repeatability (RSD = 3.86 %). The proposed technique was successfully employed to detect VER in real blood samples and pharmaceutical tablets with quantitative extraction recovery (99.40 %–100.05 %).
研究领域:
分析化学
·
电化学传感
·
药物分析
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）