Optimization of Welding Conditions for Sealing of Lithium-Ion Battery by Pulsed Nd:YAG Laser

Kim, Jong Do; Yoo, Seung Jo; Kim, Jang Soo

doi:10.4028/www.scientific.net/msf.580-582.523

Cited by 5 publications

(4 citation statements)

References 2 publications

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“…A battery pack for EVs typically consists of a large number of battery cells that must be assembled together with robust joints to ensure mechanical and electrical properties. Efforts have been taken to investigate several joining technologies, such as resistance welding, laser welding, ultrasonic welding, and mechanical fastening [1,2]. Among all these techniques, ultrasonic welding, a solid state joining process, is widely regarded as one of the best for battery joining due to its capability of joining dissimilar, multiple, and thin layers at low temperatures [3][4][5][6][7][8][9].…”

Section: Introductionmentioning

confidence: 99%

Transient Temperature and Heat Flux Measurement in Ultrasonic Joining of Battery Tabs Using Thin-Film Microsensors

Li¹,

Choi²,

Ma³

et al. 2013

Journal of Manufacturing Science and Engineering

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Process physics understanding, real time monitoring, and control of various manufacturing processes, such as battery manufacturing, are crucial for product quality assurance. While ultrasonic welding has been used for joining batteries in electric vehicles (EVs), the welding physics, and process attributes, such as the heat generation and heat flow during the joining process, is still not well understood leading to time-consuming trial-and-error based process optimization. This study is to investigate thermal phenomena (i.e., transient temperature and heat flux) by using micro thin-film thermocouples (TETC) and thin-film thermopile (TETP) arrays (referred to as microsensors in this paper) at the very vicinity of the ultrasonic welding spot during joining of three-layered battery tabs and Cu buss bars (i.e., battery interconnect) as in General Motors's (GM) Chevy Volt. Microsensors were first fabricated on the buss bars. A series of experiments were then conducted to investigate the dynamic heat generation during the welding process. Experimental results showed that TETCs enabled the sensing of transient temperatures with much higher spatial and temporal resolutions than conventional thermocouples. It was further found that the TETPs were more sensitive to the transient heat generation process during welding than TETCs. More significantly, the heat flux change rate was found to be able to provide better insight for the process. It provided evidence indicating that the ultrasonic welding process involves three distinct stages, i.e., friction heating, plastic work, and diffusion bonding stages. The heat flux change rate thus has significant potential to identify the insitu welding quality, in the context of welding process monitoring, and control of ultrasonic welding process. The weld samples were examined using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) to study the material interactions at the bonding interface as a function of weld time and have successfully validated the proposed three-stage welding theory.

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Section: Introductionmentioning

confidence: 99%

Transient Temperature and Heat Flux Measurement in Ultrasonic Joining of Battery Tabs Using Thin-Film Microsensors

Li¹,

Choi²,

Ma³

et al. 2013

Journal of Manufacturing Science and Engineering

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show abstract

“…In particular, the PTA welding method is known to have many advantages compared to other welding methods [1][2][3]. Moreover, there are numerous papers that have investigated about both mechanical and corrosion characteristics on their welding zones when the many types of steel equipment have been manufactured with various welding methods [4][5][6][7][8][9][10][11][12][13], however, there are little experimental results on their corrosion resistance and mechanical properties when the repair welding is performed for the purpose of repairing of the exhaust valve seat.…”

Section: Introductionmentioning

confidence: 99%

Evaluation on the Corrosion and Wear Resistance of Welding Zone Welded with Plasma Transferred Arc Welding Method

Jeong

Moon

Lee

et al. 2016

KEM

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There are many welding methods which have been currently performed to prolong the life time of exhaust valve of marine engine from an economic point of view. In this study, one of these welding methods, plasma transferred arc (PTA) welding was performed at the base metal of Nimonic 80A which would be used as the material of exhaust valve with three kinds of filler metals such as Stellite 6, Inconel 625 and Inconel 718. The mechanical and corrosion characteristics were investigated with electrochemical and wear loss test methods. The Nimonic 80A as the base metal had a better corrosion resistance than those of the weld metals welded with three types of the filler metals. However, after post weld heat treatment, all these weld metals mentioned above exhibited better corrosion resistance compared to the base metal, shifting the corrosion potential to the noble direction, and pitting corrosion was more or less observed at the surface of Nimonic 80A after post weld heat treatment. In particular, Inconel 625 showed the best corrosion resistance among the filler metals after heat treatment. The wear ratio of Stellite 6 showed the lowest value due to its highest hardness among the filler metals, however, its ratio by cavitation test exhibited the highest value. It is considered that increasing of embrittlement with increasing the hardness was resulted in increasing the wear loss by cavitation test.

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“…Recently, various welding methods are being widely used in all over the area, for examples, not only repair welding but also products of numerous steel structures. Hence, various welding methods are being also developed constantly, and also there are many papers about mechanical [1][2][3] and corrosion [4][5]properties in welding zone of products of numerous steel structures. However, there is little electrochemical study for corrosion resistance of the base and weld metal zone in case of repair welding for exhaust valve.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of Effect of Welding Methods to Corrosion and Hardness Characteristics of Welded Zone

Lee

Won

Park

et al. 2013

AMR

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Recently a fuel oil of the diesel engine in the merchant ship has been changed with heavy oil of low quality as the oil price is getting higher and higher .Therefore, the wear and corrosion against all parts of the engine are significantly increased with using of heavy oil of low quality. In particular, the degree of wear and corrosion in between spindle and seat ring of exhaust valve are more serious compared to the other parts of the engine due to severe environment such as the high temperature of exhaust gas and repeating impact. Thus, repair welding is a unique method to prolong their lifetime in an economical point of view. In this study, an effect of welding methods to corrosion and mechanical properties of both weld and base metal zone was investigated with some electrochemical methods such as measurement of corrosion potential, cathodic and anodic polarization curves, cyclic voltammogram and AC impedance etc. in. The hardness of the weld metal zones exhibited comparatively higher values than that of the base metal zone. And their corrosion resistances were also increased compared to the base metal. The weld metal zone of P1F( plasma welding with 1 pass) showed a relatively good corrosion resistance as well as the hardness compared to the other welding methods. Consequently, it is considered that plasma welding method is a desirable method compared to other welding methods for both better corrosion and hardness properties.

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Optimization of Welding Conditions for Sealing of Lithium-Ion Battery by Pulsed Nd:YAG Laser

Cited by 5 publications

References 2 publications

Transient Temperature and Heat Flux Measurement in Ultrasonic Joining of Battery Tabs Using Thin-Film Microsensors

Transient Temperature and Heat Flux Measurement in Ultrasonic Joining of Battery Tabs Using Thin-Film Microsensors

Evaluation on the Corrosion and Wear Resistance of Welding Zone Welded with Plasma Transferred Arc Welding Method

Evaluation of Effect of Welding Methods to Corrosion and Hardness Characteristics of Welded Zone

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