The raw material selected for this research was Brazil chestnut shells (BCs), which were utilized to gain porous carbon as a positive electrode for lithium–sulfur batteries (LSBs). The effects of N/S co-doped on the electrochemical properties of porous carbon materials were studied using thiourea as nitrogen and sulfur sources. The experimental results indicate that the N/S co-doped carbon materials have a higher mesopore ratio than the undoped porous carbon materials. The porous carbon material NSPC-2 has a lotus-like structure with uniform pore distribution. The N and S doping contents are 2.5% and 5.4%. The prepared N/S co-doped porous carbon materials were combined with S, respectively, and three kinds of sulfur carbon composites were obtained. Among them, the composite NSPC-2/S can achieve the initial specific discharge capacity of 1018.6 mAh g− 1 at 0.2 C rate. At 1 C rate, the initial discharge capacity of the material is 730.6 mAh g− 1, and the coulomb efficiency is 98.6% and the capacity retention rate is 71.5% after 400 charge–discharge cycles.

In recent times, there has been a significant demand for supercapacitors in energy storage applications due to their rapid charging– discharging capabilities, high power density, and excellent stability. Nevertheless, the synthesis of electrode materials with a substantial surface area, exceptionally high porosity, and superior electrochemical performance is still challenging. Activated carbons with a distinctive porous structure and exceptional electrochemical properties emerged as promising electrode materials for supercapacitors. In this study, we used a porous activated carbon (PAC) derived from petroleum coke followed by KOH activation as an efficient anodic electrode material. The ultra-high Brunauer–Emmett–Teller surface area of 2105.6 m2 g− 1 with stacked layers of carbon atoms arranged in a two-dimensional hexagonal structure makes the PAC an efficient candidate for a supercapacitor electrode. The PAC delivers a specific capacitance of 470 F g− 1 at a current density of 0.5 A g− 1 over a potential window of 0 to −1 V. The excellent cycling stability in a three-electrode setup with a capacitance retention of ⁓98% even at a high current density of 10 A g− 1 makes the PAC a potential anodic electrode material for high-performance supercapacitor applications.

Refined structured tin dioxide gets the amount of attraction because of its low cost and stability. The C@SnO2 nanospheres with mesoporous structures were produced using the hard template method in this work. The C@SnO2 is primarily gained attributed to the dehydration condensation of C6H12O6 and the hydrolysis of SnCl4 ·5H2O. The morphology of the C@SnO2 was analyzed by physical characterization and the diameter of the obtained C@SnO2 was around 138 nm. When C@SnO2 was applied to lithium-ion batteries as anode material, it performed outstanding electrochemical properties, with a capacity of 735 and 539 mA h g− 1 maintained at 1000 and 2000 mA g− 1, respectively. Furthermore, it exhibits favorable discharge/ charge cycle stability. This is probably because of the more chemically redox active sites provided by C@SnO2 nanocomposites and it also allows fast ion diffusion and electron migration.

The need for lightweight yet strong materials is being demanded in all industries. Carbon fiber-reinforced plastic is a material with increased strength by attaching carbon fiber to plastic, and is widely used in the aerospace industry, ships, automobiles, and civil engineering based on its low density. Carbon-reinforced fiber plastic is a material widely used in parts and manufactured products, and structural analysis simulation is required during design, and application of actual material properties is necessary for accurate structural analysis simulation. In the case of carbon-reinforced fiber plastics, it is reported that there is a porosity of around 0.5% to 6%, and it is necessary to check the change in material properties according to the porosity and pore shape. It was confirmed by applying the method. It was confirmed that the change in elastic modulus according to the porosity was 10.7% different from the base material when the porosity was 6.0%, and the Poisson's ratio was confirmed to be less than 3.0%. It was confirmed that the elliptical spherical pore derived different material properties from the spherical pore depending on the pore shape, and it was confirmed that the shape of the pore had to be confirmed to derive equivalent material properties.

The development of functional carbon materials using waste biomass as raw materials is one of the research hotspots of lithium-sulfur batteries in recent years. In this work, used a natural high-quality carbon source—coffee grounds, which contain more than 58% carbon and less than 1% ash. Honeycomb-like S and N dual-doped graded porous carbon (SNHPC) was successfully prepared by hydrothermal carbonization and chemical activation, and the amount of thiourea used in the activation process was investigated. The prepared SNHPC showed excellent electrochemical energy storage characteristics. For example, SNHPC-2 has a large pore volume (1.85 cm3·g− 1), a high mesoporous ratio (36.76%), and a synergistic effect (S, N interaction). As the cathode material of lithium-sulfur batteries, SNHPC-2/S (sulfur content is 71.61%) has the highest specific capacity. Its initial discharge-specific capacity at 0.2 C is 1106.7 mAh·g−1, and its discharge-specific capacity after 200 cycles is still as high as 636.5 mAh·g−1.

본 연구에서는 다공성 보와 논로컬 매개변수 사이의 관계에 대한 유한요소해석을 수행한다. 논로컬 매개변수는 다공성 보의 결함을 표현하는 변수들로 정의하여, 하중조건 및 경계조건에 대한 수치모사를 통해 계산한다. 다공성 보와는 반대 개념의 결함을 가지는 보에 대한 해석도 수행하였다. 이러한 보들의 거동은 논로컬 매개변수의 항으로 표현하였으며, 이 매개변수는 구멍의 지름의 제곱 그리고 원기둥 지름의 세제곱에 비례하는 것을 확인하였다. 특히 작은 원기둥을 가지는 보에 축하중을 가하는 경우, 예상과는 다르게 3 차원 유한요소 해석 결과와 2차원 평면응력 해석 결과는 다름을 알 수 있었다.

본 연구에서는 “이온젤” 이라고 불리는 고분자 기반의 PVA(polyvinyl alcohol) 기반의 고체 전 해질에 이온성 액체 BMIMBF4 (1-buthyl-3-methylimidazolium tetrafluoroborate)를 첨가하여 제조한 전 고체 전해질과 활성탄소와 금속유기골격체 복합재료 기반의 전극 재료를 이용하여 슈퍼커패시터를 제작 하였으며, 유기골격체의 유 무에 따른 전기화학적 특성을 분석하여 보았다. 슈퍼커패시터의 전기화학적 특 성은 순환전압전류법(CV), 전기화학적 임피던스 분광법(EIS) 및 전정류 충·방전법(GCD)을 통하여 비교 및 분석하여 보았다. 그 결과로, 금속유기골격체가 함유되지 않은 슈퍼커패시터의 전기용량값은 380 F/g 으로 확인 할 수 있었고, 이 값은 금속유기골격체를 첨가하였을 때 340 F/g로 감소하는 현상을 확인할 수 있었 다. 이러한 결과로 1 wt%의 금속유기골격체의 함유량은 전기화학적 특성 감소에 영향을 주는 것으로 사료 되며 이러한 결과를 바탕으로 금속유기골격체의 첨가량을 최적화 할 필요가 있다고 판단된다

Porous materials such as polymeric foam are widely adopted in engineering and biomedical fields. Porous materials often exhibit complex nonlinear behaviors and are sensitive to material and environmental factors including cell size and shape, amount of porosity, and temperature, which are influenced by the type of base materials, reinforcements, method of fabrication, etc. Hence, the material characteristics of porous materials such as compressive stress-strain behavior and void volume fraction according to aforementioned factors should be precisely identified. In this study, unconfined uniaxial compressive test for two types of closed-cell structure polyurethane foam, namely, 0.16 and 0.32 g/cm3 of densities were carried out. In addition, the void volume fraction of three different domains, namely, center, surface and buckling regions under various compressive strains (10%, 30 %, 50 % and 70 %) were quantitatively observed using Micro 3D Computed Tomography(micro-CT) scanning system. Based on the experimental results, the relationship between compressive strain and void volume fraction with respect to cell size, density and boundary condition were investigated.

Reduction in the amount of Ag salts in the membranes is required for practical applications in the industry. However, since the separation performance is directly related to the amount of Ag salts, it has been difficult to reduce the amount of Ag salts. In this study, we succeeded in preparing polymer/Ag salts/Al(NO3)3 membranes with 30% reduction in the amount of Ag salts by utilizing KIT-6, which is a porous material. When KIT-6 was incorporated into the polymer/Ag salts/Al(NO3)3 membrane, the separation performance for propylene/propane mixed gas increased with a propylene over propane selectivity of 20 and mixed gas permeance of 10 GPU. The enhanced separation performance is attributed to both the coordination of hydroxyl groups in KIT-6 with Ag ions and the porous properties of KIT-6.

This study investigated the microstructure and tensile properties of a recently made block-type Ni-Cr-Al powder porous material. The block-type powder porous material was made by stacking multiple layers of powder porous thin plates with post-processing such as additional compression and sintering. This study used block-type powder porous materials with two different cell sizes: one with an average cell size of 1,200 μm (1200 foam) and the other with an average cell size of 3,000 μm (3000 foam). The γ-Ni and γ’-Ni3Al were identified as the main phases of both materials. However, in the case of the 1,200 foam, a β-NiAl phase was additionally observed. The relative density of each block-type powder porous material, with 1200 foam and 3000 foam, was measured to be 5.78% and 2.93%, respectively. Tensile tests were conducted with strain rates of 10−2~10−4 sec−1. The test result showed that the tensile strength of the 1,200 foam was 6.0~7.1 MPa, and that of 3,000 foam was 3.0~3.3 MPa. The elongation of the 3,000 foam was higher (~9%) than that (~2%) of the 1,200 foam. This study also discussed the deformation behavior of block-type powder porous material through observations of the fracture surface, with the results above.

The composite of porous silicon (Si) and amorphous carbon (C) is prepared by pyrolysis of a nano-porous Si + pitch mixture. The nano-porous Si is prepared by mechanical milling of magnesium powder with silicon monoxide (SiO) followed by removal of MgO with hydrochloric acid (etching process). The Brunauer-Emmett-Teller (BET) surface area of porous Si (64.52 m2g−1) is much higher than that before etching Si/MgO (4.28 m2g−1) which indicates pores are formed in Si after the etching process. Cycling stability is examined for the nano-porous Si + C composite and the result is compared with the composite of nonporous Si + C. The capacity retention of the former composite is 59.6% after 50 charge/discharge cycles while the latter shows only 28.0%. The pores of Si formed after the etching process is believed to accommodate large volumetric change of Si during charging and discharging process.

Nickel-based and iron-based alloys have been developed and commercialized for a wide range of high performance applications at severely corrosive and high temperature environment. This alloy foam has an outstanding performance which is predestinated for diesel particulate filters, heat exchangers, and catalyst support, noise absorbers, battery, fuel cell, and flame distributers in burners in chemical and automotive industry. Production of alloy foam starts from high-tech coating technology and heat treatment of transient liquid-phase sintering in the high temperature. These technology allow for preparation of a wide variety of foam compositions such as Ni, Cr, Al, Fe on various pore size of pure nickel foam or iron foam in order for tailoring material properties to a specific application.

A technology of hardening porous materials of titan powders has been elaborated. The technology is based on passing alternating current with duration of ~10-1...101 s through porous (35...40%) blanks made by method of Sintering by Electric Discharge (SED) by passing a pulse of current with duration of ~10-5...10-3 s. The influence of technological regimes of porous blanks treatment on their structure and properties is investigated. Geometry and dimension of contact necks between powder particles of obtained samples are evaluated. Variations of porosity and strengths as well as microstructure of porous samples materials before and after treatment are investigated. Optimum range of treatment technological regimes is determined within which porosity of 30...35% with maximum strength values.

A porous material with a surface layer was fabricated using glass abrasive sludge and expanding agents. The glass abrasive sludges were mixed with expanding agents and compacted into pellets. These pellets were sintered in the range of for 20min. The sintered porous materials had a surface layer with smaller pores and inner parts with larger pores. The surface layer and pores controlled the absorption ratio and physical properties.