The alternative advanced lead-acid battery is one of the promising ultrabattery. The lead-carbon battery is also reusable battery consisted of positive electrodes, negative electrode and Electrolyte. Currently, numerous research efforts are performing on activated carbon used as the novel cathode materials. In this study, we have used graphite sheet coated P60 carbon as a cathode material. Graphite electrode is different form used in the normal lead-carbon batteries. It will be expected to increase the conductivity and weigh light. Through charge-discharge experiment and EIS, battery performance analysis were compared with grid form negative electrode. After that, SEM, RAMAN and XRD analyses were studied.

A novel cation exchange membrane consisting of polyvinylidene difluoride (PVDF) was prepared for the application of vanadium redox flow battery (VRFB). PVDF used as supporter has considerably high mechanical strength and an intrinsic hydrophobicity. For the successful preparation of the membrane, PVDF powders were modified by potassium hydroxide, which increased the hydrophilicity of PVDF powders. Modified PVDF were grafted with styrene sulfonic acid (SSA) using benzoyl peroxide (BPO) as initiative. The cross-sectional morphology and structure of PVDF/SSA was confirmed by scanning electron microscopy (SEM) and FT-IR. The membrane was characterized by water uptake, dimensional change, ion conductivity and ion exchange capacity (IEC) and cell performance of Vanadium Redox Flow Battery (VRFB) with Nafion 212.

Composite membranes are prepared by sulfonated poly(ether ether ketone) (sPEEK) / poly(vinylidene fluoride) (PVdF) / urethane acrylate non-ionomer (UAN) for vanadium redox flow battery (VRFB). To make sPEEK and PVdF compatible each other, amphiphilic polymer, UAN, is introduced into the composite membrane. By increasing the content of UAN, proton conductivity increases, while permeability decreases, therefore, the selectivity increases. This is attributed to improved compatibility in the composite membrane, which is confirmed by analyzing morphology on its cross-section. The performance of these VRFBs is better than that of VRFB including Nafion 212 due to high selectivity. Based on these results, it is revealed that composite membrane is useful for enhancement in VRFB performance.

In this study, several kinds of active carbons with high specific surface area and micro pore structure were prepared from the coconut shell charcoal using chemical activation method. The physical property of prepared active carbon was investigated by experimental variables such as activating chemical agents to char coal ratio, flow rate of inert gas and temperature. It was shown that chemical activation with KOH and NaOH was successfully able to make active carbons with high surface area of 1900~2500 m2/g and mean pore size of 1.85~2.32 nm. The coin cell using water-based binder in the electrolyte of LiPF6 dissolved in mixed organic solvents (EC:DMC:EMC=1:1:1 vol%) showed better capacity than that of oil-based binder. Also, it was found that the coin cell of water-based binder shows an improved cycling performance and coulombic efficiency.

납축전지 활물질 제작 공정 중 숙성공정에서 온도 제어를 통해 활물질 결정 크기를 제어할 수 있고, 생성된 활물질에 따라 초기 성능 향상, 내구성능 향상 효과를 얻을 수 있었다. 숙성반응 후 생성된 활물 중 3BS는 초기성능에는 유리 하였고, 4BS의 경우 초기 성능은 불리하였으나 내구 성능이 3BS활물질에 비해 48% 향상 되었다. 자동차용 납축전지를 ISG시스템이 적용된 자동차에 사용하기 위해 평가하는 DOD17.5% 수명시험 평가 결과, 일반 자동차 시동용으로 널리 사용하고 있는 Flooded 납축전는 적합하지 않은 것으로 확인 되었고, AGM 납축전지가 적합한 것으로 확인되었다. 그리고 3BS 활물질을 적용한 AGM 납축전지에 비해 4BS 활물질을 적용한 AGM 납축전지가 내구력이 우수하여 ISG 시스템에 적용된 자동차에 적합한 것으로 확인 되었다.

두 종류의 막(다공성 막, 양이온교환막)을 사용하여 아연-브롬 레독스-흐름 전지(ZBRFB, Zn-Br redox-flow battery)의 성능을 평가하였다. ZBRFB의 성능평가는 20mA/cm2의 전류밀도에서 진행하였다. 다공성 막인 SF-600을 사용한 ZBRFB의 기전력(SOC 100%에서의 OVC)은 1.87 V, 양이온교환막인 Nafion117 막을 사용한 ZBRFB의 기전력은 1.93 V를 나타냈다. 각 막을 사용한 ZBRFB의 성능은 7회 충 방전 실험을 진행하여 평가하였다. SF600 막을 사용한 ZBRFB의 평균 전류효율은 89.76%, 평균 전압효율은 83.46%, 평균 에너지효율은 74.88%를 나타냈으며, Nafion117 막을 사용한 ZBRFB의 평균 전류효율은 97.7%, 평균 전압효율은 76.33%, 평균 에너지효율은 74.56%를 나타냈다.

The effects of particle size of Li-Si alloy and LiCl-KCl addition as a binder phase for raw material of anode were investigated on the formability of the thermal battery anode. The formability was evaluated with respect to filling density, tap density, compaction density, spring-back and compressive strength. With increasing particle size of Li-Si alloy powder, densities increased while spring-back and compressive strength decreased. Since the small spring-back is beneficial to avoiding breakage of pressed compacts, larger particles might be more suitable for anode forming. The increasing amount of LiCl-KCl binder phase contributed to reducing spring-back, improving the formability of anode powder too. The control of particle size also seems to be helpful to get double pressed pellets, which consisted of two layer of anode and electrolyte.

The electrochemical properties of cells assembled with the LiNiO2 (LNO) recycled from cathode materialsof waste lithium secondary batteries (Li[Ni,Co,Mn]O2), were evaluated in this study. The leaching, neutralization andsolvent extraction process were applied to produce high-purity NiSO4 solution from waste lithium secondary batteries.High-purity NiO powder was then fabricated by the heat-treatment and mixing of the NiSO4 solution and H2C2O4.Finally, LiNiO2 as a cathode material for lithium ion secondary batteries was synthesized by heat treatment and mixingof the NiO and Li2CO3 powders. We assembled the cells using the LiNiO2 powders and evaluated the electrochemicalproperties. Subsequently, we evaluated the recycling possibility of the cathode materials for waste lithium secondary bat-tery using the processes applied in this work.

Positive plate was composed of lead hydroxide via reaction between lead oxide and H2O and lead sulfate was formed of the reaction of lead hydroxide with sulfuric acid. And its density is 3.8 g/cm3, 4.0 g/cm3, 4.2 g/cm3 and 4.4 g/cm3 by controlling volume of refined water. Curing of positive plate is done for low (45℃, 40hr, over 95% of relative humidity) & high (80℃, 40hr, over 95% of relative humidity) temperature, which created 3BS & 4BS active materials. Experimental result of DOD with 100% life cycle test shows that it was not related to the density of active materials but to the low & high temperature aging of active materials. The test makes us to understand that the crystallization which is made by curing of active materials is a more of a main factor than density of active materials under the deep cycle using circumstances. The active materials which were from the high temperature curing are better for deep cycle performance.

FeS2 has been widely used for cathode materials in thermal battery because of its high stability and currentcapability at high operation temperature. Salts such as a LiCl-KCl were added as a binder for improving electrical per-formance and formability of FeS2 cathode powder. In this study, the effects of the addition of Li2O in LiCl-KCl binderon the formability of FeS2 powder compact were investigated. With the increasing amount of Li2O addition to LiCl-KClbinder salts, the strength of the pressed compacts increased considerably when the powder mixture were pre-heat-treatedabove 350oC. The heat-treatment resulted in promoting the coating coverage of FeS2 particles by the salts as Li2O wasadded. The observed coating as Li2O addition might be attributed to the enhanced wettability of the salt rather than itsreduced melting temperature. The high strength of compacts by the Li2O addition and pre-heat-treatment could improvethe formability of FeS2 raw materials.

In industrial situation, electronic and electro-mechanical systems have been using different type of batteries in rapidly increasing numbers. These systems commonly require high reliability for long periods of time. Wider application of battery for low-power design as a prime power source requires us knowledge of failure mechanism and reliability of batteries in terms of load condition, environment condition and other explanatory variables. Battery life is an important factor that affects the reliability of such systems. There is need for us to understand the mechanism leading to the failure state of battery with performance characteristic and develop a method to predict the life of such battery. The purpose of this paper is to develope the methodology of monitoring the health of battery and determining the condition or fate of such systems through the performance reliability to predict the remaining useful life of primary battery with load condition, operating condition, environment change in light of battery life variation. In order to evaluate on-going performance of systems and subsystems adopting primary batteries as energy source, The primitive prototype for performance reliability analysis device was developed and related framework explained.

Silicon-carbon composite was prepared by the magnesiothermic reduction of mesoporous silica and subsequent impregnation with a carbon precursor. This was applied for use as an anode material for high-performance lithium-ion batteries. Well-ordered mesoporous silica(SBA-15) was employed as a starting material for the mesoporous silicon, and sucrose was used as a carbon source. It was found that complete removal of by-products (Mg2Si and Mg2SiO4) formed by side reactions of silica and magnesium during the magnesiothermic reduction, was a crucial factor for successful formation of mesoporous silicon. Successful formation of the silicon-carbon composite was well confirmed by appropriate characterization tools (e.g., N2 adsorption-desorption, small-angle X-ray scattering, X-ray diffraction, and thermogravimetric analyses). A lithium-ion battery was fabricated using the prepared silicon-carbon composite as the anode, and lithium foil as the counter-electrode. Electrochemical analysis revealed that the silicon-carbon composite showed better cycling stability than graphite, when used as the anode in the lithium-ion battery. This improvement could be due to the fact that carbon efficiently suppressed the change in volume of the silicon material caused by the charge-discharge cycle. This indicates that silicon-carbon composite, prepared via the magnesiothermic reduction and impregnation methods, could be an efficient anode material for lithium ion batteries.

Cathode materials and their precursors are prepared with transition metal solutions recycled from the thewaste lithium-ion batteries containing NCM (nickel-cobalt-manganese) cathodes by a H2 and C-reduction process. Therecycled transition metal sulfate solutions are used in a co-precipitation process in a CSTR reactor to obtain the tran-sition metal hydroxide. The NCM cathode materials (Ni:Mn:Co=5:3:2) are prepared from the transition metal hydroxideby calcining with lithium carbonate. X-ray diffraction and scanning electron microscopy analyses show that the cathodematerial has a layered structure and particle size of about 10 µm. The cathode materials also exhibited a capacity ofabout 160 mAh/g with a retention rate of 93~96% after 100 cycles.

Tungsten oxide films were prepared by an electrochemical deposition method for use as the anode in rechargeable lithium batteries. Continuous potentiostatic deposition of the film led to numerous cracks of the deposits while pulsed deposition significantly suppressed crack generation and film delamination. In particular, a crack-free dense tungsten oxide film with a thickness of ca. 210 nm was successfully created by pulsed deposition. The thickness of tungsten oxide was linearly proportional to deposition time. Compositional and structural analyses revealed that the as-prepared deposit was amorphous tungsten oxide and the heat treatment transformed it into crystalline triclinic tungsten oxide. Both the as-prepared and heat-treated samples reacted reversibly with lithium as the anode for rechargeable lithium batteries. Typical peaks for the conversion processes of tungsten oxides were observed in cyclic voltammograms, and the reversibility of the heat-treated sample exceeded that of the as-prepared one. Consistently, the cycling stability of the heat-treated sample proved to be much better than that of the as-prepared one in a galvanostatic charge/discharge experiment. These results demonstrate the feasibility of using electrolytic tungsten oxide films as the anode in rechargeable lithium batteries. However, further works are still needed to make a dense film with higher thickness and improved cycling stability for its practical use.

본 논문에서는 배터리 전극 해석을 위한 응력-확산 완전 연계 멀티스케일 해석기법을 고안하였다. 제안된 방법에서는 먼저 리튬농도에 따른 확산계수 및 기계적 물성을 계산하였다. 이를 고려하여 확산에 의한 응력뿐만 아니라 응력에 의한 확산거동 변화까지 모두 고려한 응력-확산 완전연계 연속체 모델을 유한요소 기반으로 구성하였다. 이를 통해 실리콘 나노와이어 음극의 충/방전 전산 모사를 수행하였다. 이러한 해석결과를 통하여 기존의 확산에 의한 응력 연속체 모델보다 더 실제와 가까운 해석결과를 제안된 방법이 보여줌을 확인할 수 있었다.

A three dimensional numerical analysis was performed to study the cooling performance of xEV battery module depending on cooling fluid inlet position. Depending on the inlet position from the top, case 1 (top inlet), case 2 (middle inlet), and case 3 (bottom inlet) are selected. For the case 1, the temperature of the battery near inlet was higher than that of the battery near outlet. For the case 2 and 3 the temperature of the battery near inlet was lower than that of the battery near outlet. From the analysis result, the cooling performance is higher in the order of case 2, case 3, and case 1.

Numerical analysis of the electric vehicle battery was performed for the optimization of the thermal management under various operating conditions. For the analysis of internal flow and temperature distributions under the different operating conditions of battery, the battery system which was packed 18 battery cell with -25℃∼ 65℃ operating temperature range was considered, and the air flow rate, velocity, and ambient temperature conditions were varied and compared. It was revealed that the cooling system for battery was necessary to maintain its performance for hot ambient conditions. Especially, in this condition, at least 90m3/h of air flow rate are required to maintain the module temperature under 40℃. However, heating system of battery for cold ambient conditions doesn't need.

This analytical work was performed to reveal the effect of inlet geometry of battery pack on the temperature distributions and flow stream line for a electric vehicle. To achieve this, standard k-ε model with wall function was applied and the working conditions of battery pack under different air flow rate and inlet area according to the geometry were estimated. It was revealed that as inlet area was smaller, the flow velocity was faster, and it can't cover the whole area of battery module. In case of two inlet case, the cooling efficiency of air flow is less than that of one inlet case because of low flow rate.

본 연구는 온실 운영에 필요한 전력량을 확보함으로서 온실경영비 절감을 목적으로 태양광발전시스템을 온실에 인접한 건물의 옥상에 설치하여 일사량에 따른 발전량을 실험적으로 검토하였다. 연구결과를 요약하면 다음과 같다. 실험기간 동안 수평면 일사량의 최대, 평균 및 최소 값은 각각 26.1MJ · m−2, 14.0MJ · m−2 및 0.6MJ · m−2 정도였고, 일일 전력량은 각각 약 6.1kWh, 3.7kWh 및 0.01kWh 이었다. 그리고 누계 일사량과 전력량은 각각 약 4,378.2MJ · m−2 및 1,163.2kWh 정도이었다. 그리고 부하에 의해 소비된 적산전력량의 최대, 평균 및 최소값은 각각 4.5kWh, 2.4kWh 및 0.0kWh 정도이었고, 누계 전력량은 739.2kWh 정도로서 발생 전력량의 약 63.5% 에 해당하였다. 본 실험에 사용된 시스템의 평균 소비전 력량을 기준으로 보면, 온풍기의 용량 및 작동시간이 작은 경우는 충분하지만 큰 경우는 부족한 것으로 나타났다. 어레이 표면온도가 상대적으로 높아지면 일사량에 비례해서 발생 전력이 증가하지 않은 것으로 나타났지만, 두 인자 간에 상관계수는 0.851 정도로서 상관관계가 높은 것으로 나타났다.

The temperature distribution of a generic battery module was analyzed for different flow rates of cooling fluid. For the given battery module design, the temperature of battery cell near the inlet is higher than that of battery cell near the outlet. Because the inlet is located at the higher elevation than the top of battery electrodes, most of the incoming cooling fluid flows directly towards the battery housing wall above the outlet. For the inlet velocities of 1, 3, 5 m/s, the maximum temperature differences are 28, 19, 15 degrees Celcius respectively.