• Journal of the Microelectronics and Packaging Society
• /
• 제27권4호
• /
• pp.83-89
• /
• 2020

For the past few decades, as part of efforts to protect the environment where fossil fuels, which have been a key energy resource for mankind, are becoming increasingly depleted and pollution due to industrial development, ecofriendly secondary batteries, hydrogen generating energy devices, energy storage systems, and many other new energy technologies are being developed. Among them, the lithium-ion battery (LIB) is considered to be a next-generation energy device suitable for application as a large-capacity battery and capable of industrial application due to its high energy density and long lifespan. However, considering the growing battery market such as eco-friendly electric vehicles and drones, it is expected that a large amount of battery waste will spill out from some point due to the end of life. In order to prepare for this situation, development of a process for recovering lithium and various valuable metals from waste batteries is required, and at the same time, a plan to recycle them is socially required. In this study, we introduce a nanoscale pattern transfer printing (NTP) process of Li2CO3, a representative anode material for lithium ion batteries, one of the strategic materials for recycling waste batteries. First, Li2CO3 powder was formed by pressing in a vacuum, and a 3-inch sputter target for very pure Li2CO3 thin film deposition was successfully produced through high-temperature sintering. The target was mounted on a sputtering device, and a well-ordered Li2CO3 line pattern with a width of 250 nm was successfully obtained on the Si substrate using the NTP process. In addition, based on the nTP method, the periodic Li2CO3 line patterns were formed on the surfaces of metal, glass, flexible polymer substrates, and even curved goggles. These results are expected to be applied to the thin films of various functional materials used in battery devices in the future, and is also expected to be particularly helpful in improving the performance of lithium-ion battery devices on various substrates.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• 제20권6호
• /
• pp.80-85
• /
• 2019

Vanadium dioxide is a well-known metal-insulator phase transition material. Lots of researches of vanadium redox flow batteries have been researched as large scale energy storage system. In this study, vanadium oxide($VO_x$) thin films were applied to cathode for lithium ion battery. The $VO_x$ thin films were deposited on Si substrate($SiO_2$ layer of 300 nm thickness was formed on Si wafer via thermal oxidation process), quartz substrate by RF magnetron sputter system for 60 minutes at $500^{\circ}C$ with different RF powers. The surface morphology of as-deposited $VO_x$ thin films was characterized by field-emission scanning electron microscopy. The crystallographic property was confirmed by Raman spectroscopy. The optical properties were characterized by UV-visible spectrophotometer. The coin cell lithium-ion battery of CR2032 was fabricated with cathode material of $VO_x$ thin films on Cu foil. Electrochemical property of the coin cell was investigated by electrochemical analyzer. As the results, as increased of RF power, grain size of as-deposited $VO_x$ thin films was increased. As-deposited thin films exhibit $VO_2$ phase with RF power of 200 W above. The transmittance of as-deposited $VO_x$ films exhibits different values for different crystalline phase. The cyclic performance of $VO_x$ films exhibits higher values for large surface area and mixed crystalline phase.

• Journal of the Korean Electrochemical Society
• /
• 제16권1호
• /
• pp.9-18
• /
• 2013

Components of zinc-air battery and their problems are explained. Energy density of zinc air battery is superior to other commercial ones including Li-ion batteries. Cycle life of the zinc air batteries is poor because of irreversible redox reactions on both electrodes. In order to improve the performance of the zinc air battery, catalysts, passivation, and the new structure of electrodes should be developed to optimize several reactions in an electrode. Multidisciplinary efforts, such as mechanics, corrosion science, composite materials are necessary from the beginning of the research to obtain a meaningful product.

• Journal of the Korean Ceramic Society
• /
• 제56권1호
• /
• pp.65-70
• /
• 2019

Simple fabrication of a powdered Ge-reduced graphene oxide (Ge-rGO) composite via spray pyrolysis and reduction is introduced herein. Successful incorporation of the rGO nanosheets with Ge hindered the aggregation of Ge and conferred enhanced structural stability to the composite by alleviating the mechanical stress associated with drastic volume changes during repeated cycling. The Li-ion storage performance of Ge-rGO was compared with that of powdered Ge metal. The reversible discharge capacity of Ge-rGO at the $200^{th}$ cycle was $748mA\;h\;g^{-1}$ at a current density of $1.0A\;g^{-1}$ and Ge-rGO showed a capacity of $375mA\;h\;g^{-1}$ even at a high current density of $5.0A\;g^{-1}$. The excellent performance of Ge-rGO is attributed to the structural robustness, enhanced electrical conductivity, and formation of open channels between the rGO nanosheets, which facilitated electrolyte penetration for improved Li-ion diffusion.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• 제41권7호
• /
• pp.665-671
• /
• 2017

The alkali-Metal Thermal-to-electric Converter (AMTEC) is one of the promising static energy conversion technologies for the direct conversion of thermal energy to electrical energy. The advantages over a conventional energy converter are its high theoretical conversion efficiency of 40% and power density of 500 W/kg. The working principle of an AMTEC battery is the electrochemical reaction of the sodium through an ion conducting electrolyte. Sodium ion pass through the hot side of the beta"-alumina solid electrolyte (BASE) primarily as a result of the pressure difference. This pressure difference across the BASE has a significant effect on the overall performance of the AMTEC system. In order to build the high pressure difference across the BASE, hermeticity is required for each joined components for high temperature range of $900^{\circ}C$. The AMTEC battery was manufactured by utilizing robust joining technology of BASE/insulator/metal flange interfaces of the system for both structural and electrical stability. The electrical potential difference between the anode and cathode sides, where the electrons emitted from sodium ionization and recombined into sodium, was characterized as the open-circuit voltage. The efforts of technological improvement were concentrated on a high-power output and conversion efficiency. This paper discusses about the joining and performance of the AMTEC systems.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• 제32권1호
• /
• pp.78-85
• /
• 2019

The effect of various lithium sources such as LiCl, LiOH, and Li-metal on the microstructure and electrochemical properties of granulated $SiO_x$ powders were investigated. Various lithium sources were metallurgically added for a passive pre-lithiation of $SiO_x$ to improve its low initial coulombic efficiency. In spite of using the same amount of Li in various sources, as well as the same process conditions, different lithium silicates were obtained. Moreover, irreversible phases were formed without reduction of $SiO_x$, which might be from additional oxygen incorporation during the process. Accordingly, there were no noticeable electrochemical enhancements. Nevertheless, the $Li_4SiO_4$ phase changes the initial electrochemical reaction, and consequently the relationship between the microstructure and electrochemical properties of metallurgically pre-lithiated $SiO_x$ could provide a guideline for the optimization of the performance of lithium ion batteries.

• Resources Recycling
• /
• 제23권4호
• /
• pp.21-29
• /
• 2014

Nickel, cobalt and manganese-based(NCM, $Li(Ni_xCo_yMn_z)O_2$) cathode active materials of spent lithium-ion batteries contained valuable metals such as cobalt(15 ~ 20%), nickel(25 ~ 30%), manganese(10 ~ 15%) and lithium(5 ~ 10%). It was investigated the eco-friendly leaching process for the recovery of valuable metal from spent lithium-ion battery NCM cathode active materials by DL-malic acid($C_4H_5O_6$) as an organic leachant in this research. The experiments were carried out to optimize the process parameters for the recovery of cobalt, nickel and lithium by varying the concentration of lixivant, reductant concentration, solid/liquid ratio and temperature. The leaching solution was analyzed using ICP-OES(Inductively Coupled Plasma Optic Emission Spectrometer). Cathode active materials of 5 wt. % were introduced into the leaching solution which was 2 M DL-malic acid in addition of 5 vol. % $H_2O_2$ at $80^{\circ}C$ and it resulted in the recovery of 99.10% cobalt, 99.80% nickel and 99.75% lithium in 120 min. $H_2O_2$ in DL-malic acid solution acts as an effective reducing agents, which enhance the leaching of metals.

• Bulletin of the Korean Chemical Society
• /
• 제30권8호
• /
• pp.1733-1737
• /
• 2009

A new cathode material based on Li$Ni_{0.8}Co_{0.15}Al_{0.05}O_2$ (LNCA)/polyaniline (Pani) composite was prepared by in situ self-stabilized dispersion polymerization in the presence of LNCA. The materials were characterized by fourier transform infrared spectroscopy (FT-IR), ultraviolet-visible spectroscopy (UV-Vis), X-ray diffraction (XRD), and scanning electron microscopy (SEM). Electrochemical properties including galvanostatic charge-discharge ability, cyclic voltammetry (CV), capacity, cycling performance, and AC impedance were measured. The synthesized LNCA/Pani had a similar particle size to LNCA and exhibited good electrochemical properties at a high C rate. Pani (the emeraldine salt form) interacts with metal-oxide particles to generate good connectivity. This material shows good reversibility for Li insertion in discharge cycles when used as the electrode of lithium ion batteries. Therefore, the Pani coating is beneficial for stabilizing the structure and reducing the resistance of the LNCA. In particular, the LNCA/Pani material has advantageous electrochemical properties.

• Journal of Welding and Joining
• /
• 제31권6호
• /
• pp.58-64
• /
• 2013

Several joining methods involving resistance welding, laser welding, ultrasonic welding and mechanical joining are currently applied in manufacturing lithium-ion batteries. Cu and Al alloys are used for tab and bus bar materials, and laser welding characteristics for these alloys were investigated with similar and dissimilar material combinations in this study. The base materials used were Al 1050 and oxygen-free Cu 1020P alloys, and a disk laser was used with a continuous wave mode. In bead-on-plate welding of both alloys, the joint strength was higher than the strength of O tempered base material. In overlap welding, the effect of welding parameters on the tensile shear strength and bead shape was evaluated. Tensile shear strength of overlap welded joint was affected by interfacial bead width and weld defect formation. The tensile-shear specimen was fractured at the heat affected zone by selecting proper laser welding parameters.

• Resources Recycling
• /
• 제24권6호
• /
• pp.9-16
• /
• 2015

In a recycling scheme of spent lithium ion batteries, a co-precipitation process for the re-synthesis of precursor is essential after the leaching of lithium ion battery scraps. In this study, the effect of ammonia as impurity during the co-precipitation process was investigated in order to re-synthesize a precursor of Ni-rich cathode active material $LiNi_{0.6}Co_{0.2}Mn_{0.2}O_2$ (NCM 622). As ammonia concentration increases from 1 M (the optimum condition for synthesis of the precursors based on 2 M of metal salt solution) to 4 M, the composition of obtained precursors deviates from the designed composition, most notably for Ni. The Ni co-precipitation efficiency gradually decreases from 100% to 87% when the concentration of ammonia solution increases from 1 M to 4 M. Meanwhile, the morphological properties of the obtained precursors such as sphericity, homogeneity and size distribution of particles were also investigated.