Secondary Molten Research Articles

Planar Sodium‐Nickel Chloride Batteries with High Areal Capacity for Sustainable Energy Storage

AbstractHigh‐temperature sodium‐nickel chloride (Na‐NiCl2) batteries are a promising solution for stationary energy storage, but the complex tubular geometry of the solid electrolyte represents a challenge for manufacturing. A planar electrolyte and cell design is more compatible with automated mass production. However, the planar cell design also faces a series of challenges, such as the management of molten phases during cycling. As a result, cycling of planar high‐temperature cells until now focused on moderate areal capacities and current densities. In this work, planar cells capable of integrating cost‐efficient nickel/iron electrodes at a substantially enhanced areal capacity of 150 mAh cm−2 is presented. Due to a low cell resistance during operation at 300 °C, these cells deliver a specific discharge energy of 300 Wh kg−1 at high discharge current densities of 80 mA cm−2 (C/2, 10%–100% state‐of‐charge). This results represent the first demonstration of planar Na‐NiCl2 cells at a commercially relevant combination of areal capacity, cycling rate, and energy efficiency. It is further identified the secondary molten NaAlCl4 electrolyte to contribute to the cell capacity during cycling. Mitigating electrochemical decomposition of NaAlCl4 will play an important role in further enhancing both cycling rates and cycle life of high temperature Na‐NiCl2 batteries.

Effect of ZnO on the crystallization behavior and properties of SiO2–CaO–Al2O3–Fe2O3 glass-ceramics prepared from simulated secondary slag after reduction of copper slag

The feasibility of preparing low-cost glass-ceramics from Zn-containing dust and secondary molten slag generated during the carbothermal reduction of copper slag was investigated. Analytical-grade agents, such as ZnO, Fe2O3, SiO2, CaO, and Al2O3, were used to simulate the dust and secondary slag. The effect of ZnO content on the crystallization behavior, structure, and mechanical properties of the glass-ceramics was investigated through X-ray diffraction analysis, scanning electron microscopy-energy dispersive spectrometry, differential scanning calorimetry, Fourier transform infrared spectroscopy, and Raman spectroscopy. The results showed that with increased ZnO content from 0 to 6 wt%, the crystallization activation energy of base glass increased from 386.05 to 425.89 kJ/mol. Meanwhile, the average value of the crystal growth index increased from 1.91 to 4.10, and the highest crystallization rate of the glass-ceramics increased from about 1.44 to 23.11 mm3/min. The increased ZnO in glass-ceramics promoted the precipitation of gehlenite, but inhibit the crystallization of anorthite. When the ZnO content was 6 wt%, the comprehensive properties of the glass-ceramics were better; the flexural strength, microhardness, volume density, water absorption rate, and open porosity were 58.67 MPa, 738.35 HV, 2.92 g/cm3, 0.44% and 1.27%, respectively.

분석화학을 통한 전선 용융흔의 분석기법 향상에 관한 연구

With the steady increase in electricity use, electric fires account for more than 20% of the total number of fires each year. Electrical fires are caused by electrical arcs or sparks inside the cover of wires, but they are also caused by external flames melting the cover of wires into contact with each other. In electric fires, melting of wires is usually found, which is commonly referred to as short circuit. The molten marks are divided into the primary one that occurs inside the wire and causes the fire directly, the secondary one caused by external fire, and the heat melt found in the unenergized state. Scientific criteria for the distinction between primary and secondary molten mark is presented by using qualitative and quantitative analysis, through analytical chemistry such as SEM and EDS, XRD and EA.

Electrolysis of a molten semiconductor.

Metals cannot be extracted by electrolysis of transition-metal sulfides because as liquids they are semiconductors, which exhibit high levels of electronic conduction and metal dissolution. Herein by introduction of a distinct secondary electrolyte, we reveal a high-throughput electro-desulfurization process that directly converts semiconducting molten stibnite (Sb2S3) into pure (99.9%) liquid antimony and sulfur vapour. At the bottom of the cell liquid antimony pools beneath cathodically polarized molten stibnite. At the top of the cell sulfur issues from a carbon anode immersed in an immiscible secondary molten salt electrolyte disposed above molten stibnite, thereby blocking electronic shorting across the cell. As opposed to conventional extraction practices, direct sulfide electrolysis completely avoids generation of problematic fugitive emissions (CO2, CO and SO2), significantly reduces energy consumption, increases productivity in a single-step process (lower capital and operating costs) and is broadly applicable to a host of electronically conductive transition-metal chalcogenides.

Study on Discrimination between Primary and Secondary Molten Marks by Analyzing the Crystal Structure of the Carbon in Carbonized Residue

Study on Discrimination between Primary and Secondary Molten Marks by Analyzing the Crystal Structure of the Carbon in Carbonized Residue

Study on Discrimination between Primary and Secondary Molten Marks by DAS

Study on Discrimination between Primary and Secondary Molten Marks by DAS

Study on Discrimination between Primary and Secondary Molten Marks at Attachment Plugs and Receptacles

Study on Discrimination between Primary and Secondary Molten Marks at Attachment Plugs and Receptacles

A Study on Discrimination between Primary and Secondary Molten Marks on Blades of Electric Plugs by DAS

Molten marks on electric plugs or wall sockets found in fire sites often are great help, when we investigate the cause of the fires. It is known that the distance between each second arm of crystals called DAS (Dendrite Arm Spacing), that we see on the cross section of those molten marks, change depending on the atmospheric temperature at the time of a short circuit. Also it is already known that DAS between primary and secondary marks are clearly different. We created reference data to make use of DAS for practical investigation. In this study, we showed the relation between atmospheric temperature and DAS by making samples of molten marks at various temperatures. And we examined if this method was able to help assume the surrounding temperature at the time when the molten mark was produced. As a result, we found that the method has some possibility. We developed a new method for assuming the atmospheric temperature at the time of the short circuit using the reference data.

Study on discrimination between primary and secondary molten marks using carbonized residue

In most places where a fire started, electric molten marks that may be the cause of the fire are found. Various methods have been studied for identifying these electric molten marks to be either the cause of a fire (a primary molten mark (PMM)) or one caused by the flames of the fire (a secondary molten mark (SMM)). Little was studied, however, on their identification using the carbonized residue remaining in the molten marks. In this study, therefore, it was examined whether it was possible to discriminate between the PMMs and SMMs by analyzing the crystal structure of the carbon in the carbonized residue, which came from PVC insulation, remaining in the primary and the SMMs. As a result, it has been found that PMMs contain both graphitized carbon and amorphous carbon, whereas SMMs only contain amorphous carbon.

Discrimination between Primary and Secondary Molten Marks on Electric Wires by DAS

Discrimination between Primary and Secondary Molten Marks on Electric Wires by DAS

Al-Si合金の複合鋳込みによる等軸晶の微細化と等軸晶域の拡大

In this study, a primary solidifying alloy was added with a secondary melt of a lesser volume. The former and the latter were termed as the primary and secondary molten metals, respectively, and the process as duplex casting. Al-3 mass%Si alloy was used as the primary molten metal, and pure Al and Al-3 mass%Si alloy were used as the secondary molten metal. The time interval between pourings of the primary and secondary molten metals in the mold varied from 4 to 15 s. The results showed finer equiaxed crystals with the increase in pouring interval. The equiaxed crystals were finer, when Al was used as the secondary molten metal, because of the extension of the constitutionally supercooled region. It was also observed that there was an optimum time interval for the extension of the equiaxed region when Al-3 mass%Si alloy was used as the secondary molten metal; it was shorter when Al was used.