• IE interfaces
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• v.18 no.4
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• pp.402-411
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• 2005

Secondary batteries with high performance are essential in widespread use of modern portable devices such as cellular phones and laptop computers. High energy density, long cycle life, and safety are some of important requirements for secondary battery. To achieve such characteristics, a mixing proportion of electrolyte solution ingredients in the battery should be carefully chosen. In this paper, using statistical design of mixture experiments (DOME), we attempt to find an optimum condition of designing the secondary battery. DOME has a distinct feature in that the experimental region is represented by simplex, rather than hypercube, because the sum of blend proportions should be unity. Several designs based upon this point have been proposed for mixture experiments. Among them, an extreme vertices design is employed in this paper because there are a couple of blend constraints to be considered. In order to investigate how the mixing proportion interacts with other manufacturing factors, a fractional factorial design is also included across the extreme vertices design. As a result, we find that the blend proportion of solution ingredients has a significant effect on battery performances. By simultaneously optimizing two battery capacities, this paper proposes an optimum blend proportion according to process factor settings.

• Proceedings of the KIPE Conference
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• 2013.11a
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• pp.115-116
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• 2013

Recently environmental problems such as greenhouse gas emissions has become a global problem. As a result, the current that can be easily used to Petroleum and coal reserves of fossil energy and environmental issues, coupled with the limitations of this finding for renewable energy to replace the movement is spreading around the world. Among them Energy Storage System with secondary battery technology has been increased interest in, Redox flow batteries, unlike the conventional theory, the life of the rechargeable battery almost no restrictions existing lithium-ion batteries 10 times more than the life of the road. In this paper, power plant or power system, installed in a building that can cope with the rapid increase in demand for power redox flow battery for 100kW PCS will be introduced.

• Journal of Internet Computing and Services
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• v.11 no.3
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• pp.33-41
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• 2010

The battery consumption and the wireless communication pattern were analyzed for the low power and the improvement of channel interferences between of Zigbee networks and WPAN(Wireless Personal Area Network). The communication patterns considering end device's battery saving during channel searching period were analyzed for low power consumption topology of Zigbee dynamic ad-hoc characteristics. And, the communication patterns were analyzed due to channel interferences between WLAN and Random Back off of Zigbee, too. As a result, the communication patterns of Zigbee's coordinator and end devices is alleviated for the longer battery life time of Zigbee's end device due to Zigbee's end device setting techniques.

• Journal of Power Electronics
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• v.17 no.5
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• pp.1288-1297
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• 2017

The estimation of the remaining useful life (RUL) of lithium-ion (Li-ion) batteries is important for intelligent battery management system (BMS). Data mining technology is becoming increasingly mature, and the RUL estimation of Li-ion batteries based on data-driven prognostics is more accurate with the arrival of the era of big data. However, the support vector machine (SVM), which is applied to predict the RUL of Li-ion batteries, uses the traditional single-radial basis kernel function. This type of classifier has weak generalization ability, and it easily shows the problem of data migration, which results in inaccurate prediction of the RUL of Li-ion batteries. In this study, a novel multi-kernel SVM (MSVM) based on polynomial kernel and radial basis kernel function is proposed. Moreover, the particle swarm optimization algorithm is used to search the kernel parameters, penalty factor, and weight coefficient of the MSVM model. Finally, this paper utilizes the NASA battery dataset to form the observed data sequence for regression prediction. Results show that the improved algorithm not only has better prediction accuracy and stronger generalization ability but also decreases training time and computational complexity.

• Journal of Hydrogen and New Energy
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• v.13 no.4
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• pp.259-269
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• 2002

A battery based on the lithium/elemental sulfur redox couple has the advantage of high theoretical specific capacity of 1,675 mAh/g-sulfur. However, Li/S battery has bad cyclic durability at room temperature due to sulfur active material loss resulting from lithium polysulfide dissolution. To improve the cycle life of Li/S battery, PEGDME (Poly(ethylene glycol) dimethyl ether) 500 containing 1M LiTFSI salt which has high viscosity was used as electrolyte to retard the polysulfide dissolution and nano-sized $Mg_{0.6}Ni_{0.4}O$ was added to sulfur cathode as additive to adsorb soluble polysulfide within sulfur cathode. From experimental results, the improvement of the capacity and cycle life of Li/S battery was observed( maximum discharge capacity : 1,185 mAh/g-sulfur, C50/C1 = 85 % ). Through the charge-discharge test, we knew that PEGDME 500 played a role of preventing incomplete charge-discharge $behavior^{1,2)$. And then, in sulfur dissolution analysis and rate capability test, we first confirmed that nano-sized $Mg_{0.6}Ni_{0.4}O$ had polysulfide adsorbing effect and catalytic effect of promoting the Li/S redox reaction. In addition, from BET surface area analysis, we also verified that it played the part of increasing the porosity of sulfur cathode.

• Journal of Energy Engineering
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• v.20 no.2
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• pp.77-83
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• 2011

It is requested to improve negative electrode of Ni-Zn battery for industrial application. Ni-Zn battery has main problems not to commercialize because of short life cycle, heavy gassing and fast electrolyte vaporization so far. It has been studied on 8 cells performances under promoting electric, additional materials and binders changed. With these materials($Ca(OH)_2$, $Bi_2O_3$), negative electrolyte can be manufactured equal and tight as well as low gassing. Furthermore, to supply EG-EP#12(gravity 1.26), keeping stable electrolyte gravity in battery, the life cycle of Ni-Zn battery is extremely improved 200~300% than initial performance.

• Journal of IKEEE
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• v.27 no.4
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• pp.477-485
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• 2023

In this paper, the effect of AC ripple on the lifetime of lithium-ion batteries is experimentally analyzed. Bidirectional power conversion system(PCS) is used to increase the efficiency of energy storage systems (ESS). When connected to the grid, a current ripple with a frequency twice the grid frequency is applied to the battery due to its structure. Therefore, to analyze the effect of AC ripple on Li-ion battery aging, cycle life test are performed by applying charge/discharge profiles of DC current and DC+AC current ripple specifications. Based on the experimental results, direct current internal resistance (DCIR), incremental capacitance (IC), and surface temperature were analyzed. As a result, it is confirmed that AC ripple does not directly affect degradation and that battery degradation slows down after a certain cycle. These results can serve as a guideline for optimizing filters to reduce ripple on the battery side in applications where AC ripple occurs.

• Journal of Hydrogen and New Energy
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• v.13 no.4
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• pp.287-296
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• 2002

현재 자동차의 문제점을 해결할 수 있는 가장 착실한 엔진은 수소를 이용한 연료 전지라고 판단된다. 연료전지는 화학적 에너지를 전기적 에너지로 직접 변환하는 장치이다. 순수한 연료전지 차량과 연료전지 하이브리드 차량을 비교 분석하였다. 연료전지 하이브리드 차량에서 고려하여야할 점은 효율, 연료경제성, 출력 특성 등이 있다. FUDS 싸이클 시뮬레이션 비교를 하면 하이브리드화가 순수 연료전지 차량 보다 효율이 높다. 이는 회생 제동 에너지를 이용할 수 있으며 battery를 이용하여 연료전지를 효율적인 영역에서 작동하게 할 수 있기 때문이다. Life cycle 비용은 연료전지의 크기, 연료전지의 가격, 수소의 가격 등에 지배적인 영향을 받는다. 연료전지의 가격이 고가이면 하이브리드화가 유리하나, 연료전지의 가격이 400$/kW 이하가 되면 순수한 연료전지 자동차가 비용면에서 유리 하다.

• Journal of Electrochemical Science and Technology
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• v.9 no.4
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• pp.339-344
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• 2018

The gelling agent used in Zn-air cells plays a role in improving battery life. It prevents the evaporation of water and diffusion of $Zn^{2+}$ ions away from the current collector. Additional functionality was incorporated by replacing some of the gelling agents with new materials. Alcohols with moderate viscosity, namely maltose, sucrose, poly ethylene glycol 600, and 2-hydroxyethyl cellulose, were used to replace some gelling agents in this work. Among these alcohols, poly ethylene glycol 600 and 2-hydroxyethyl cellulose improved the cycle life of full cells. This improved cycle life was attributed to the inhibition of water electrolysis and the improved cycle life of the anode.

• Journal of Hydrogen and New Energy
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• v.29 no.2
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• pp.212-218
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• 2018

Li-ion battery system is regarded as one of the most potent power sources for electrified power-trains. For the Li-ion battery system to be widely adopted in automotive applications, the performance, safety, and cycle life issues need to be properly addressed. These issues are closely related to the thermal management of battery system. Especially, the effective cooling module design is the core part for the novel battery thermal management system development. In this paper, an experimental approach was carried out as a basic part of comprehensive battery thermal management research. The main goal of this paper is to present a comparison of two cooling systems (air cooling and phase change material (PCM) based cooling) of the unit 18650 battery module. The temperature rise with different battery discharge rate (c-rate) was mainly investigated and analyzed for two types of battery cooling systems. It is expected that this study can properly contribute to providing basic insights into the design of robust battery thermal management system for vehicular applications.