Thermal batteries are designed to activate at high temperatures (~500℃), therefore, the electrodes used in these systems are typically made into pellet form using compression molding techniques that do not involve polymer binders. However, the compression molding technique poses limitations in scaling up the electrode area without increasing thickness for high-power properties. Additionally, the tape casting method has been studied as a way to solve with, but too low a loading level is still an obstacle to practical use. This study fabricated a film cathode of high loading level (35.79 mAh·cm^-2) using the tape casting method for these problem. As utilized fabricated cathode, it investigated the influence of electrode thickness and density on electrochemical performance. Furthermore, a film cathode with a larger area but the same amount of active material as the pellet was fabricated, enabling the design of high-power cells with the same energy density. We expect that the fabricated film cathode with a high loading level and scalable area will enable the development of various thermal battery designs.

Lithium-ion batteries are utilized as an energy source for electric vehicles because of their advantages such as excellent cyclability, high energy density, high capacity, high efficiency, and low price. However, lithium-ion batteries use combustible electrolytes, which have also reported problems related to fire safety. Therefore, research on the fire safety of lithium-ion batteries is actively being conducted. In this study, detection criteria for the fire safety of lithium-ion batteries were proposed through incremental capacity analysis (ICA) and frequency analysis. The experimental results showed that the battery micro internal short circuit (MISC) indicator could be identified through changes in specific frequency bands and fluctuations in the ICA curve.

Powder compaction technology is widely used to prepare thermal battery components. This method, however, is limited by the size, thickness, and geometry of the battery components. This limitation leads to excessive cell capacity, overweight, and higher cost of the pellets, which decreases the specific capacities and delays the activation time of thermal batteries. FeS₂ thin-film cathodes were fabricated by tape-casting technology and analyzed by SEM and EDS in this paper. The residual organic binder of the FeS₂ thin-film cathodes decreased with the temperature of the heat treatment, which improved the specific capacity because of the lower resistance. Specific capacities of the FeS₂ thin-film cathodes decreased because of the higher residual binder and the restrictive reaction of active materials with molten salts as the thickness increased. FeS₂ thin-film cathodes showed much higher specific capacity (1,212.2 As/g) than pellet cathodes (860.7 As/g) at the optimal heat-treatment temperature (230℃).

In this study, the electrostatic capacity and dielectric loss tangent for 20 μm thick thermal conductivity silicone rubber which is heated at 80 degrees for 8 hours has been measured at temperature of 30℃∼170℃, frequency of 0.1∼1 MHz. The results of degradation evaluation by this study are as follows. In low frequency, it found that the electrostatic capacity decreased with increasing temperature. On the other hand, it confirmed that the range of the electrostatic capacity narrowed with increasing frequency. It confirmed that there are the carboxylic acid structure and C-O bonding at range of wave number 1,000cm-1 to 1,300cm-1.

In this work, LiMn2O4 and LiNi1/3Mn1/3Co1/3O2 cathode materials are mixed by some specific ratios to enhance the practical capacity, energy density and cycle performance of battery. At present, the most used cathode material in lithium ion batteries for EVs is spinel structure-type LiMn2O4. LiMn2O4 has advantages of high average voltage, excellent safety, environmental friendliness, and low cost. However, due to the low rechargeable capacity (120 mAh/g), it can not meet the requirement of high energy density for the EVs, resulting in limiting its development. The battery of LiMn2O4-LiNi1/3Mn1/3Co1/3O2 (50:50 wt%) mixed cathode delivers a energy density of 483.5 mWh/g at a current rate of 1.0 C. The accumulated capacity from 1st to 150th cycles was 18.1 Ah/g when the battery is cycled at a current rate of 1.0 C in voltage range of 3.2~4.3 V.

In this study, the properties of C-V degradation for thermal conductivity silicone rubber sample which is attached by copper-copper, copper-aluminum, aluminum-aluminum on upper-side and under-side has been measured at temperature of 80℃∼140℃. The results of this study are as follows. In case the frequency is increased, it found that the electrostatic capacity increased with increasing temperature to 80℃, 110℃, 140℃ regardless of kind of electrode. It found that the electrostatic capacity increased with becoming high temperature range of frequency regardless of kind of electrode. This result is considered to be caused by thermal absorption on the thermal conductivity silicone rubber sample. It found that the electrostatic capacity decreased with increasing temperature and frequency. This result is considered to be caused by molecular motion of C-F radical or OH radical.

In this study, the frequency properties of electrostatic capacity and dielectric loss for the samples with different types of filler has been measured in through the applied frequency range of 7 kHz -3,000 kHz at temperature of 80℃, 110℃, 140℃, 170℃. The results of this study are as follows. When the sample is degradated at the temperature of 80℃, 110℃, 140℃, 170℃ and the frequency range of 7 kHz -3,000 kHz is applied, It found that the electrostatic capacity of the sample with Polyimide film is larger than the sample with Grass fiber. It found that the dielectric loss for the sample with Polyimide film is larger than the sample with Grass fiber with increasing frequency and temperature in the 80℃, 110℃, 140℃, 170℃ range. Also, the dielectric loss decreased with increasing frequency. In case of the sample with Polyimide film, It found that the electrostatic capacity decreased with increasing temperature, and the dielectric loss gradually decreased with increasing frequency.

In this study, the temperature characteristics of electrostatic capacity and dielectric loss for thesample of Teflon film which is degradated at the 120℃∼200℃ temperature range in the oven for 10 hourshas been measured in through the applied frequency range of 0.1 kHz∼4,800 kHz at temperature of 50℃,90℃, 130℃, 170℃. Also, in the same conditions, the frequency characteristics of electrostatic capacity anddielectric loss for the sample of Teflon film has been measured in through the applied temperature rangeof 30℃∼70℃ on setting frequency of 0.1 kHz, 1 kHz, 10 kHz, 100 kHz. The results of this study are asfollows. When the frequency range of 0.1 kHz∼4,800 kHz applied to the sample of Teflon film, theelectrostatic capacity has been measured at the temperature of 50℃, 90℃, 130℃, 170℃. Through thismeasurement, it found that the electrostatic capacity decreased with increasing temperature. Regarding thisresult, may be it is because the electromagnetic coupling is degraded by thermal degradation. When thesample of Teflon film heated at 280℃ for 10 hours in oven, the dielectric loss has changed from unstablestatus to stabilizing status with increasing the degradation temperature in the 120℃, 160℃, 200℃ range. Inthis measurement, the two spectrums of dielectric loss appeared. It considers that this spectrum ofdielectric loss appeared in 300 Hz is caused by the molecular motion of the C-F or OH group. Throughthis study, It found that the electrostatic capacity decreased with increasing frequency and temperature,and there is no change in dielectric loss, although the frequency increases.

In this study, the moisture content, charge?discharge current, electrostatic capacity and dielectric loss tangent are measured for the specimen of bisphenol type epoxy resin which is mixed with squared amorphous silica filler and dipped in hot water of 50℃ for 169 days. The results of this study are listed below. The longer of deposition day, the charge and discharge current was increased. It is considered that the reason is because there was water attack through the squared silica surface. The longer of deposition day, the absorption rate of all specimens was increased. It found that the absorption rate reached saturated state after 100 days. The higher frequency and the longer of deposition day, the tanδ was decreased. Also, It found that the tanδ and electrostatic capacity of the specimen which is mixed with squared filler are greater.

In this paper, semiconducting shield specimens for a DC cable os fabricated and characterized by measurement of volume resistance, tensile strength, and the coefficient of expansion to show the electrical and mechanical characteristics of the semiconducting shield. Due to the PTC phenomenon, the volume resistance at 25℃ increases rapidly in comparison to the volume resistance at 90℃. Since the compounding ration of carbon black is low, the tensile strength and density become lower and the coefficient of expansion is increased. As the general specification of the tensile strength and density is 0.8 kgf/mm2 and 150%, respectively, the fabricated specimen in this paper has excellent mechanical characteristic.