• Journal of Electrochemical Science and Technology
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• v.15 no.2
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• pp.314-320
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• 2024

Lithium dendrite formation is one of the most significant problems with lithium metal batteries. The lithium dendrite reduces the lithium metal batteries' cycling life and safety. To apply consistent external pressure to a lithium metal pouch cell, we design a press jig in this study. External pressure creates dense lithium morphology by preventing lithium dendrite formation. After 300 cycles at 1 C, the cells with the external pressure perform far better than the cells without it, with a cycling retention of 97.8%. The formation of stable lithium metal is made possible by external pressure, which also enhances safety and cyclability.

• Journal of Korean Society for Atmospheric Environment
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• v.15 no.1
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• pp.41-51
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• 1999

In this study, the two dimensional morphology of particle accumulates on a cylindrical fiber was numerically simulated when a uniform external electric field was present across a cylindrical fiber. In order to investigate the mechanism of linear dendrite formation which is observed under the above electrostatic condition, the electrostatic forces between a newly introduced particle and each deposited particle were calculated and compared with those between the particle and fiber As a result of this study it was found that dielectrophoretic forces between the oncoming particle and fiber play principal roles in linear dendrite formation.

• Transactions of the Korean hydrogen and new energy society
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• v.26 no.6
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• pp.532-540
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• 2015

Electrochemical alane ($AlH_3$) production process can be provided as a synthesis route which close a reversible cycle. In this study, growth inhibition of dendrite as key issues in this process was investigated. Main cause of dendrite growth was because Al fine powder separated in consumption process of Al electrode was moved to Pd electrode. In an effort to avoid this, use of glass block with uniform holes was the most effective to inhibit the amount of dendrite to that of $AlH_3$. Furthermore, effects of Al electrode (anode) type and electrolyte concentration were investigated and the optimal condition for inhibiting dendrite formation was proposed.

• Laser Solutions
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• v.7 no.3
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• pp.25-36
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• 2004

This study was performed to clarification of the formation of weld discontinuities in the dissimilar laser fusion zone. Welding parameters were beam power of 1300, 1430, 1560, and 1700 W and travel speed of 1, 1.3, and 1.7 m/min. Most cavities in the fusion zone were observed near the tip. Cavities in the fusion zone observed to be formed and grown from pores in the tip. More cavities were formed as the beam position moves to the tip side. Small cavities were decreased but large cavities were increased when the energy input increased. W content in the fusion zone was increased with heat input and as the beam position close to the tip. In the fusion zone, W content in the dendrite boundary was increased with heat input. Considering the propagation path and fracture morphology, cracks were solidification cracking, and were initiated and propagated along the dendrite boundaries. The formation of cracks might be related with the W rich ${\mu}$ phase which was formed in the grain boundaries and dendrite boundaries.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.5 no.3
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• pp.197-208
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• 1995

An experiment study of the dendrite growth of ice crystals growing in quiescent pure subcooled water was made at small subcoolings of 0.035 K < ${\Delta}T$ < 1.000 K. It was observed that the growth kinetics and morphology are functions of not only subcooling but also thermal convection. When the subcooling is less than 0.35K, it was found that effect of thermal convection on growth kinetics of ice dendrites becomes important. Quantitiative measurements of growth velocity, $V_{G}$, and tip radii of the edge and basal planes, $R_{1}$ and $R_{2}$, were made simultaneously as a function of subcooling.

• Applied Chemistry for Engineering
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• v.34 no.4
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• pp.365-382
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• 2023

A lithium metal anode with high energy density has the potential to revolutionize the field of energy storage systems (ESS) and electric vehicles (EVs) that utilize rechargeable lithium-based batteries. However, the formation of lithium dendrites during cycling reduces the performance of the battery while posing a significant safety risk. In this review, we discuss various strategies for achieving dendrite-free lithium metal anodes, including electrode surface modification, the use of electrolyte additives, and the implementation of protective layers. We analyze the advantages and limitations of each strategy, and provide a critical evaluation of the current state of the art. We also highlight the challenges and opportunities for further research and development in this field. This review aims to provide a comprehensive overview of the different approaches to achieving dendrite-free lithium metal anodes, and to guide future research toward the development of safer and more efficient lithium metal anodes.

• Proceedings of the Korean Magnestics Society Conference
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• 2000.09a
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• pp.379-380
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• 2000

• Journal of Korea Foundry Society
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• v.35 no.6
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• pp.178-184
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• 2015

Due to excellent abrasion resistance the high-chrome white irons are widely used in mining and mineral industries. Minor variation of carbon content in 28% chrome white iron resulted in difference in primarily solidified microstructure. Sub-eutectic (hypoeutectic) composition led to formation of primarily solidified dendrites. Formation of primarily solidified dendrites which were supersaturated with carbon and chrome also caused precipitation of fine secondary carbides that are different from relatively large plate type $M_7C_3$ carbides in the eutectic structure. Small portion of primarily solidified dendrite expected to contribute significantly to the improvement of abrasion resistance of the white iron because the dendrites provided mechanical support to carbides. The relative fraction of primary dendrite increased with reduction of carbon content from the eutectic composition. The increased fraction of primary dendrite increased hardness value of the white irons.

• Journal of Korea Foundry Society
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• v.7 no.3
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• pp.192-198
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• 1987

Commercial semicontinuous cast ingots of aluminum alloys often exhibit large grains composed of parallel arrays of continuous lamellae. Each lamella consists of a central {111} coherent twin boundary and wavy solidification boundary. This microstructure is referred to as a twin columnar growth(TCG) structure. The factors influencing the formation of a TCG structure include a unidirectional thermal gradient and the critical range of the alloying element content. The higher the thermal gradient is, the shorter the twin plane spacings are. The composition profile for an untwinned dendrite shows maximums at the positions of the interdendritic channels and the minimum appears at the center of the dendrite. While for twinned dendrite, it has wavy apperance. This profile has two local minimums instead of one shown in the untwinned.

• Membrane Journal
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• v.26 no.4
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• pp.310-317
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• 2016

Lithium ion secondary battery (LISB) is an energy conversion system operated via charging-discharging cycle based on Lithium ion migration. LISB has a lot of advantages such as high energy density, low self-discharge rate, and a relatively high lifetime. Recently, increasing demands of electric vehicles have been encouraging the development of LISB with high capacity. Unfortunately, it causes some critical safety issues. It includes dendrite formation on negative electrode, resulting in electric shortage problems and battery explosion. Also, the elevated temperatures occurred during the LISB operation induces thermal shrinkage of polyolefin (e.g., polyethylene and polypropylene) separators. Consequently, the low thermal stability leads to decay of LISB performances and the reduction of lifetime. In this study, sulfonated poly (arylene ether sulfone) (SPAES) random copolymers were used as key materials to prepare polyolefin pore-filling separator. The resulting separators were evaluated in the term of metal ion chelation capability associated with dendrite formation, $Li^+$ ion conductivity and thermal durability.