Ablative properties of carbon black and MWNT/phenolic composites: A comparative study

Natali, Maurizio; Monti, Marco; Puglia, Debora; Torre, Luigi

doi:10.1016/j.compositesa.2011.10.006

Cited by 149 publications

(101 citation statements)

References 32 publications

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“…The polymeric binder and conducting carbon in the cathode electrode was highly stable under inert atmosphere up to 450 °C, indicating that the carbon dioxide was not formed under inert gas flow. [47][48][49][50][51] Thus, the carbon dioxide released in the temperature range of 300−400 °C was closely related to the oxidation reaction of the carbon from the binder and conducting agent with the evolved oxygen gas in the cathode electrode. Furthermore, the nickel content in the nickel-rich cathode determines the thermal properties.…”

Section: Phase Transitionmentioning

confidence: 99%

Prospect and Reality of Ni‐Rich Cathode for Commercialization

Kim

Lee

Cha

et al. 2017

Advanced Energy Materials

665

582

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practical candidate for the wide application of the LIBs with respect to the reversible capacity, rate capability, and capital cost. [4][5][6][7] In terms of nickel contents, the nickel-rich cathodes with nickel content above 80% have advantages in gravimetric capacity, allowing high gravimetric energy density, compared with the nickel content less than 80%. Currently, the nickel-rich cathodes with the amount of nickel less than 60% are fully commercialized. However, the nickel-rich cathodes with nickel content of ≥80% still have many difficulties in the commercialization with respect to powder properties and electrode fabrication process.The unstable powder properties originate from residual lithium compounds such as LiOH and Li 2 CO 3 that formed by the spontaneous reduction of sensitive trivalent nickel ions during the synthesis process and storage in air. [8][9][10][11] The Li 2 CO 3 significantly promotes the gas evolution and increase the moisture of the cathode powder, which strongly related to the safety issue. [12][13][14] Furthermore, the LiOH on the cathode increases the powder pH value, causing the gelation of the slurry during the electrode fabrication process. The nickel-rich cathode with nickel content of ≤60% have acceptable amount of residual lithium compounds for the practical use. By contrast, the cathode with amount of nickel of ≥80% should be treated by additional process to reduce the residual lithium compounds ( Table 1). Furthermore, other powder properties, such as powder pH and moisture, should be carefully controlled when nickel contents were exceeded of ≥80%. Thus, for the practical application of these cathode materials, most battery companies have adapted the washing process, in which the cathode power was stirred in purified water for 20-40 min. [15,16] The washing process could greatly reduce the residual lithium compounds and powder pH value. [15] However, the washing process not only increases process time and capital cost but also make the nickel-rich cathode more chemically sensitive than nonwashed cathodes. [16] More seriously, the water washing deteriorates the thermal stability of the nickel-rich cathodes, indicating that the washing process should be substituted by other methods for the battery safety.Another important factor for the commercialization of the nickel-rich cathodes is the electrode density directly related to the energy density. In general, the nickel-rich cathodesThe layered nickel-rich cathode materials are considered as promising cathode materials for lithium-ion batteries (LIBs) due to their high reversible capacity and low cost. However, several significant challenges, such as the unstable powder properties and limited electrode density, hindered the practical application of the nickel-rich cathode materials with the nickel content over 80%. Herein, important stability issues and in-depth understanding of the nickel-rich cathode materials on the basis of the industrial electrode fabrication condition for the commercialization of the nickel-rich cathode m...

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Section: Phase Transitionmentioning

confidence: 99%

Prospect and Reality of Ni‐Rich Cathode for Commercialization

Kim

Lee

Cha

et al. 2017

Advanced Energy Materials

665

582

View full text Add to dashboard Cite

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Section: Introductionmentioning

confidence: 99%

“…On the basis of continuous phase (Matrix), composites materials are classified into three main broad categories, i.e. Metal matrix composites (MMCs), Ceramic matrix composites (CMCs), and Polymer matrix composites (PMCs) [2].PMCs are composed of a matrix (polymer) from thermoplastics materials (polycarbonates, polyvinyl chloride, nylon, polystyrene, etc) as continuous phase or thermoset (unsaturated polyesters, epoxies, phenolic resins, polydimethylsiloxane, etc) An ablative composite is a type of composites, which are used to protect certain structure or equipment from the intense heat environment. Mostly, such types of composites are used in aerospace industry.…”

mentioning

confidence: 99%

Comprehensive Ablation Characteristics of Ceramic Fibers Impregnated Rubber Composites

Iqbal¹

2014

IJET

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Abstract-In this novel research, aluminum silicate fibers were incorporated into ethylene propylene diene monomer (EPDM) rubber to fabricate ablative composites, achieve better ablation performance, and thermal endurance for ultrahigh temperature applications. Variant concentrations of ceramic fibers (CFs) were impregnated in the elastomeric matrix. Ablation testing of the composite specimens was carried out according to ASTM E285-08, in which oxyacetylene torch was used as a high temperature source. The obtained results showed that anti-ablation performance of the polymer composites was remarkably augmented with increasing fiber concentration in the polymer matrix. Thermal decomposition of the fabricated composites was diminished with the progressive incorporation of CFs in the EPDM matrix. Ultimate tensile strength, elongation at break, and modulus of elasticity were reduced due to the weak fiber to matrix interaction while Shore A rubber hardness was augmented with increasing fiber to matrix ratio. Voids formation & polymer pyrolysis of the ablated specimens, char reinforcement interaction, CFs dispersion in the polymer matrix, elemental analysis and fiber diameter measurement of the CF, and the compositional analysis of ablative composite were analyzed using scanning electron microscopy coupled with energy dispersive spectroscopy.Index Terms-Ablative composites, ceramic fibers, mechanical properties, thermal degradation, thermal conductivity, temperature evolution. I. INTRODUCTIONA composite is commonly defined as a combination of two or more distinct materials, each of which retains its own distinctive properties, to create a new material with desirable properties that cannot be achieved by any of the components acting alone [1]. On the basis of continuous phase (Matrix), composites materials are classified into three main broad categories, i.e. Metal matrix composites (MMCs), Ceramic matrix composites (CMCs), and Polymer matrix composites (PMCs) [2].PMCs are composed of a matrix (polymer) from thermoplastics materials (polycarbonates, polyvinyl chloride, nylon, polystyrene, etc) as continuous phase or thermoset (unsaturated polyesters, epoxies, phenolic resins, polydimethylsiloxane, etc) An ablative composite is a type of composites, which are used to protect certain structure or equipment from the intense heat environment. Mostly, such types of composites are used in aerospace industry. The basic definition of ablative composites is "These are highly endothermic sacrificial materials used to protect the hardware from ultra high temperatures and shear stresses in the propulsion system." Low backface temperature, high mechanical/thermal ablation resistance, and good interfacial adhesion between the ablative material and the aerodynamic surface are required for the composites used in Thermal Protection Systems (TPS) [3]. The main function of TPS materials is to protect the inner hardware of space vehicles and ballistic missiles from ultrahigh temperature/velocity flow of gases encountered during their mis...

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“…CNT-페놀복합재료의 경우 CNT에 의해 복합재료의 열적, 기계적 물성 강화를 확인할 수 있다 [8]. CNT 재료를 강화 재로 활용할 경우 CNT간 반데르발스의 영향으로 입자간 응집이 잘 일어난다.…”

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Microstructure and Ablation Performance of CNT-phenolic Nanocomposites

Wang¹,

Kwon²,

Park³

et al. 2013

Composites Research

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Highly ablation resistant carbon nanotube (CNT)-phenolic composites were fabricated by the addition of low concentrations of CNT nanofiller. Tensile and compressive properties as well as ablative resistance were significantly improved by the addition of only 0.1 and 0.3 wt% of uniformly dispersed CNTs. An oxygen-keroseneflame torch and a field emission scanning electron microscope (FE-SEM) were used to evaluate the ablative properties and microstructures of these CNT-phenolic composites. Thermal gravimetric analysis (TGA) revealed that the ablation rate was lower for the 0.3 wt% CNT-phenolic composites than for neat phenolic or the composite with 0.1 wt% CNT. Ablative mechanisms for all three materials were investigated using this TGA in conjunction with microstructural studies using a FE-SEM. The microstructural studies revealed that CNT acted as an ablation resistant phase at high temperatures, and that the uniformity of dispersion of the CNT played an important role in this resistance to ablation.

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Ablative properties of carbon black and MWNT/phenolic composites: A comparative study

Cited by 149 publications

References 32 publications

Prospect and Reality of Ni‐Rich Cathode for Commercialization

Prospect and Reality of Ni‐Rich Cathode for Commercialization

Comprehensive Ablation Characteristics of Ceramic Fibers Impregnated Rubber Composites

Microstructure and Ablation Performance of CNT-phenolic Nanocomposites

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