• Journal of the Korean Electrochemical Society
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• v.16 no.3
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• pp.111-122
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• 2013

Sodium sulfur (NAS) battery is a high energy storage system (ESS). These days, as the use of renewable green energy like wind energy, solar energy and ocean energy is rapidly increasing, the demand of ESS is increasing and NAS battery is considered to be one of the most promising ESS. Since NAS battery has a high energy density(3 times of lead acid battery), long cycle life and no self-charge and discharge, it is a good candidate for ESS. A NAS battery consists of sulfur as the positive electrode, sodium as the negative electrode and ${\beta}$"-alumina as the electrolyte and a separator simultaneously. Since sulfur is an insulator, carbon felt should be used as conductor with sulfur and so the composition and property of the cathode could largely influence the cell performance and life cycle. Therefore, in this paper, the composition of NAS battery, the property of carbon felt and sodium polysulfides ($Na_2S_x$, intermediates of discharge), and the effects of these factors on cycle performance of cells are described in detail.

• Journal of Electrical Engineering and Technology
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• v.11 no.5
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• pp.1063-1069
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• 2016

• Journal of Hydrogen and New Energy
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• v.27 no.6
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• pp.753-763
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• 2016

High temperature sodium/sulfur battery(Na/S battery) has good electrochemical properties, but, the battery has some problems such as explosion and corrosion at al. because of using the liquid electrodes at high temperature and production of high corrosion. Room temperature sodium/sulfur batteries (NAS batteries) is developed to resolve of the battery problem. To recently, room temperature sodium/sulfur batteries has higher discharge capacity than its of lithium ion battery, however, cycle life of the battery is shorter. Because, the sulfur electrode and electrolyte have some problem such as polysulfide resolution in electrolyte and reaction of anode material and polysulfide. Cycle life of the battery is improved by decrease of polysulfide resolution in electrolyte and block of reaction between anode material and polysulfide. If room temperature sodium/sulfur batteries (NAS batteries) with low cost and high capacity improves cycle life, the batteries will be commercialized batteries for electric storage, electric vehicle, and mobile electric items.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.3
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• pp.384-392
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• 2015

This paper presents an economic assessment of large-scale Li-ion battery energy storage systems applied to Korean power system. There are many applications of the battery energy storage systems (BESSs) and they can provide various benefits to power systems. We consider BESSs to the energy time-shift application to Korean power system and evaluate the benefits from the application of BESS in the social perspective. The mixed integer programming (MIP) algorithm is used to resolve the optimal operation schedule of the BESS. The social benefits can include the savings of the fuel cost from generating units, deferral effects of the generation capacity, delay of transmission and distribution infra construction, and incremental CO2 emission cost impacts, etc. The economic evaluation of the BESS is separately applied into Korean power systems of the Main-land and Jeju island to reflect the differences of the load and generation patterns.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.10
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• pp.269-283
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• 2021

The government policies and initiatives to guarantee sustainable energy and clean environmental conditions contributed to the introduction of green technology electricity appliances in the market. This study sought to determine the physiological and socio-economics-demographic factors driving residential electricity consumers to use green technology electricity appliances, mainly solar PV, smart meter, electric vehicle, and battery storage technology. By understanding consumer intention, the investors of solar PV, battery storage, electric vehicle, and smart meter can estimate the demand and upscale the market for the corresponding products. For that purpose, the intention to use the solar PV, smart meter, electric vehicle, and battery storage function is developed by utilizing the combination of the theory of planned behavior, technology acceptance, and reasoning action. A reliable and valid structured online questionnaire and stepwise multiple regression are used to identify the possible factors that drive consumer behavior intention. The results show that the social influence, knowledge on RE, and perceived price significantly influence residential consumers' willingness to adopt the technologies offered. The findings of this study suggest that the involvement of NGOs, public figures, and citizens' cooperation are all necessary to spread information about the government's objectives and support Malaysia's present energy and environmental policies.

• Journal of Electrical Engineering and Technology
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• v.12 no.6
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• pp.2138-2145
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• 2017

A hybrid system combining renewable technologies with diesel generators is a promising solution for rural electrification. Myanmar has many renewable energy resources, and many regions that cannot be supplied with electricity from the main grid. Therefore, in this study, we select a village in Myanmar, which is located far away from the substation, and evaluate the economic feasibility of a hybrid system for the village considering the specific local conditions and resource availability. We consider a hybrid system composed of a photovoltaic source, diesel generator, battery energy storage system, and converter. The load profiles of the household data from the village, and the solar radiation profiles are determined. The advantages of the hybrid system, in terms of cost, reliability, and environmental effects are analyzed through simulations using commercial software. The simulation results show that, for the selected village in Myanmar, a hybrid system with battery energy storage can reduce the cost and greenhouse gas emissions while maintaining reliability. We also obtain an optimized design in terms of the component size for the selected hybrid system with battery energy storage.

• Journal of Hydrogen and New Energy
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• v.17 no.3
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• pp.317-323
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• 2006

Electric conductive material should be homogeneously mixed with sulfur in sulfur electrode fabrication of lithium/sulfur battery, because sulfur is electric insulator. In this paper electrochemical properties of Li/S battery was studied with various compositions of sulfur electrodes. When content of sulfur changed from 40 wt.% to 80 wt.%, the 60 wt.% sulfur electrode showed the maximum capacity of 1489 mAh/g-sulfur. Electrochemical properties of Li/S battery using 60 wt.% sulfur was also investigated with various carbon contents. The discharge capacity changed as a function of carbon contents. The optimum composition was 25 wt.% carbon for 60 wt.% sulfur electrode.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2010.04a
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• pp.276-277
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• 2010

This paper deals with energy storage system for saving the energy of RTGC(rubber tired gantry crane). Advantage and disadvantage of battery, super-capacitor, and flywheel as an energy storage system were surveyed. Even if a flywheel energy storage system includes some problems such as manufacturing technique and high price, it is surveyed with a promising energy storage system In addition, RTGCs using battery or flywheel as the energy storage system were quantitatively presented through a survey of literatures. It was found that the both RTGC with those systems can reduced the waste of energy.

• Journal of Hydrogen and New Energy
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• v.28 no.4
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• pp.407-418
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• 2017

Battery heat management is essential for high power and high energy battery system because it affects its performance, longevity, and safety. In this paper, we investigated the temperature of the 18650 Lithium Ion Battery Module used in a Energy Storage System (ESS) and the cooling method to minimize cell-to-cell temperature variation of battery module. For uniform temperature distribution within a battery module, the flow direction of the coolant in a battery module has been changed according to the time interval, and studied the effect of the cooling method on the temperature uniformity in a battery module which includes a number of battery cells. The experimental results show that bi-directional battery cooling method can effectively reduce the cell-to-cell temperature variation compared with the one-directional battery cooling. Furthermore, it is also found that bi-directional battery cooling can reduce the maximum temperature in a battery module.

• Journal of Power Electronics
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• v.18 no.4
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• pp.1211-1222
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• 2018

This study presents a power distribution control scheme for a three-phase interleaved parallel DC/DC converter in a battery energy storage system. To extend battery life and increase the power equalization rate, a control method based on the nth order of the state of charge (SoC) is proposed for the charging and discharging processes. In the discharging process, the battery sets with high SoC deliver more power, whereas those with low SoC deliver less power. Therefore, the SoC between each battery set gradually decreases. However, in the two-stage charging process, the battery sets with high SoC absorb less power, and thus, a power correction algorithm is proposed to prevent the power of each particular battery set from exceeding its rated power. In the simulation performed with MATLAB/Simulink, results show that the proposed scheme can rapidly and effectively control the power distribution of the battery sets in the charging and discharging processes.