• Resources Recycling
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• v.33 no.3
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• pp.21-29
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• 2024

Globally, the demand for electric vehicles (EVs) is surging due to carbon-neutral strategies aimed at decarbonization. Consequently, the demand for lithium-ion batteries, which are essential components of EVs, is also rising, leading to an increase in the generation of spent batteries. This has prompted research into the recycling of spent batteries to recover valuable metals. In this study, we aimed to selectively leach and recover lithium from the cathode material of spent LFP batteries. To enhance the reaction surface area and reactivity, the binder in the cathode material powder was removed, and the material was subjected to heat treatment in both atmospheric and nitrogen environments across various temperature ranges. This was followed by a mechanochemical process for aqueous leaching. Initially, after heat treatment, the powder was converted into a soluble lithium compound using sodium persulfate (Na₂S₂O₈) in a mechanochemical reaction. Subsequently, aqueous leaching was performed using distilled water. This study confirmed the changes in the characteristics of the cathode material powder due to heat treatment. The final heat treatment in a nitrogen atmosphere resulted in a lithium leaching efficiency of approximately 100% across all temperature ranges.

• Resources Recycling
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• v.28 no.6
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• pp.79-86
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• 2019

Recently, the use of lithium ion battery(LIB) has increased. As a result, the price of lithium and the amount spent lithium on ion battery has increased. For this reason, research on recycling lithium in waste LIBs has been conducted1). In this study, the effect of roasting for the selective lithium leaching from the spent LIBs is studied. Chemical transformation is required for selective lithium leaching in NCM LiNi_xCo_yMn_zO₂) of the spent LIBs. The carbon in the waste EV cell powder reacts with the oxygen of the oxide at high temperature. After roasting at 550 ~ 850 ℃ in the Air/N₂ atmosphere, the chemical transformation is analysed by XRD. The heat treated powders are leached at a ratio of 1:10 in D.I water for ICP analysis. As a result of XRD analysis, Li₂CO₃ peak is observed at 700 ℃. After the heat treatment at 850 ℃, a peak of Li₂O was confirmed because Li₂CO₃ is decomposed into Li₂O and CO₂ over 723 ℃. The produced Li₂O reacted with Al at high temperature to form LiAlO₂, which does not leach in D.I water, leading to a decrease in lithium leaching ratio. As a result of lithium leaching in water after heat treatment, lithium leaching ratio was the highest after heat treatment at 700 ℃. After the solid-liquid separation, over 45 % of lithium leaching was confirmed by ICP analysis. After evaporation of the leached solution, peak of Li₂CO₃ was detected by XRD.

• Applied Chemistry for Engineering
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• v.35 no.1
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• pp.37-41
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• 2024

The coconut shell, a by-product of popular tropical fruit, is a promising material due to its interesting properties. The preparation of the composite consisted of conducting polymer and coconut shell using a simple wet method, and subsequent carbonization produced a carbonized material under a controlled carbonization cycle. In addition, its electrochemical performance as an anode in lithium-ion batteries was also investigated. The appearance of the obtained materials was observed with a scanning electron microscope. The internal structure of the carbon derived from the coconut shell under a controlled heating profile was analyzed using a Raman spectroscope. A simple electrical measurement based on the ohmic relationship showed that the carbonized product has a significant electrical conductivity. The application of the carbonized product as anode in a lithium-ion battery was tested using half-cell charge/discharge experiments. This article provides important information for future research regarding the recycling of fruit shells and food waste.

• Resources Recycling
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• v.10 no.6
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• pp.9-14
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• 2001

A sulfuric acid leaching of $LiCoO_2$as cathodic active materials of lithium ion secondary batteries was investigated in terms of reaction variables. In the absence of a reducing agent, the extraction of cobalt was less than 40% in 2 M sulfuric acid at $75^{\circ}C$ instead of that of lithium could be almost 100% in the same conditions. To improve the Co extraction, hydrogen peroxide was used as a reducing agent in the range 2~20 vol%. When over 10vo1% hydrogen peroxide was added, the extractions of both metals were improved to about 95%. It seems to be due to the reduction of Co(III) to Co(II) that can be readily dissolved. The extractions of Co and Li were increased with increasing $H_2$$SO_4$concentration and temperature, and amount of hydrogen peroxide and with decreasing of pulp density. The optimum leaching conditions were determined at $2 M H_2$$SO_4$concentration, $75^{\circ}C$ operating temperature, 100 g/L. initial pulp density, 20 vol% $H_2$$O_2$addition and 30 min.

• Resources Recycling
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• v.31 no.5
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• pp.59-66
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• 2022

To investigate the rate-determining step of nickel, cobalt and copper electrowinning, experiments were conducted by varying the electrolyte temperature and agitation speed using a rotating disc electrode. Analyzing the rate-determining step by calculating the activation energy in the electrowinning process, it was found that nickel electrowinning is controlled by a mixed mechanism (partly by chemical reaction and partly by mass transport), cobalt is controlled by chemical reaction, and copper is controlled by mass transfer. Electrowinning of nickel, cobalt and copper was performed by varying the electrolyte temperature and agitation speed, and the comparison of the current efficiencies was used the determine the rate-determining step.

• Resources Recycling
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• v.28 no.4
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• pp.30-36
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• 2019

In this study, Li powder was recovered from the by-product of LNO ($Li_2NiO_2$) process, which is the positive electrode active material of waste lithium ion battery, through the $CO_2$ thermal reaction process. In the process of recovering Li powder, the $CO_2$ injection amount is 300 cc/min. The $Li_2NiO_2$ award was phase-separated into the $Li_2CO_3$ phase and the NiO phase by holding at $600^{\circ}C$ for 1 min. After this, the collected sample:distilled water = 1:50 weight ratio, and after leaching, the solution was subjected to vacuum filtration to recover $Li_2CO_3$ from the solution, and the NiO powder was recovered. In order to increase the purity of Ni, it was maintained in $H_2$ atmosphere for 3 hours to reduce NiO to Ni. Through the above-mentioned steps, the purity of Li was 2290 ppm and the recovery was 92.74% from the solution, and Ni was finally produced 90.1% purity, 92.6% recovery.

• Clean Technology
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• v.27 no.2
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• pp.139-145
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• 2021

The purpose of this study is to recover valuable metals from spent batteries using a dry process. We focused on the effect of the smelting temperature on the composition of recovered solid and liquid products and collected gaseous products. After removal of the cover, the spent battery was left in NaCl solution and discharged. Then, the spent battery was made into a powder form through a crushing process. The smelting of the spent battery was performed in a tubular electric furnace in an oxygen atmosphere. For spent lithium-ion batteries, the recovery yield of the solid product was 80.1 wt% at a reaction temperature of 850 ℃, and the final product had 27.2 wt% of cobalt as well as other metals such as lithium, copper, and aluminum. Spent nickel-hydrogen batteries had a recovery yield of 99.2 wt% at a reaction temperature of 850 ℃ with about 37.6 wt% of nickel and other metals including iron. For spent nickel-cadmium batteries, the yield decreased to 65.4 wt% because of evaporation with increasing temperature. At 1050 ℃, the recovered metals were nickel (41 wt%) and cadmium (12.9 wt%). Benzene and toluene, which were not detected with the other secondary waste batteries, were detected in the gaseous product. The results of this study can be used as basic data for future research on the dry recycling process of spent secondary batteries.

• Resources Recycling
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• v.28 no.5
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• pp.60-67
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• 2019

A valuable metal recovery from waste resources such as spent rechargeable secondary batteries is of critical issues because of a sharp increase in the amount of waste resources. In this context, it is necessary to research not only recycling waste lithium-ion batteries (LIBs), but also reusing valuable metals (e.g., Li, Co, Ni, Mn etc.) recovered from waste LIBs. In particular, the lithium hydroxide ($LiOH{\cdot}xH_2O$), which is of precursors that can be prepared by the recovery of Li in waste LIBs, can be reused as a catalyst, a carbon dioxide absorbent, and again as a precursor for cathode materials of LIB. However, most studies of recycling the waste LIBs have been focused on the preparation of lithium carbonate with a recovery of Li. Herein, we show the preparation of high purity lithium hydroxide powder along with the precipitation process, and the systematic study to find an optimum condition is also carried out. The lithium carbonate, which is recovered from waste LIBs, was used as starting materials for synthesis of lithium hydroxide. The optimum precipitation conditions for the preparation of LiOH were found as follows: based on stirring, reaction temperature $90^{\circ}C$, reaction time 3 hr, precursor ratio 1:1. To synthesize uniform and high purity lithium hydroxide, 2-step precipitation process was additionally performed, and consequently, high purity $LiOH{\cdot}xH_2O$ powder was obtained.

• Resources Recycling
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• v.32 no.6
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• pp.25-33
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• 2023

With the growth of the battery industry, a rapid increase in the production and usage of lithium-ion batteries is expected, and in line with this, much interest and effort is being paid to recycle waste batteries, including production scrap. Although much effort has been made to recycle cathode material, much attention has begun to recycle anode material to secure the supply chain of critical minerals and improve recycling rates. The proximate analysis that measures the content of coal can be used to analyze graphite in anode material, but it cannot accurately analyze due to the interaction between the components of the black mass. Therefore, in this study, thermogravimetric analysis of each component of black mass was measured as the temperature increased up to 950℃ in an oxygen atmosphere. As a result, in the case of cathode material, no change in mass was measured other than a mass reduction of about 5% due to oxidation of the binder and conductive material. In the case of anode material, except for a mass reduction of about 2% due to the binder, all mass reduction were due to the graphite(fixed carbon). In addition, metal conductors (Al, Cu) were oxidized and their mass increased as the temperature increased. Thermal analysis results of mixed samples of cathode/anode show similar results to the predictive values that can be calculated through each cathode and anode analysis results.

• Journal of the Korean Society of Safety
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• v.39 no.2
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• pp.38-43
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• 2024

Recently, with the expanding market for electronic devices and electric vehicles, secondary battery usage has been on the rise. Lithium-ion batteries are particularly popular due to their fast charging times and lightweight nature compared to other types of batteries. A secondary battery consists of four components: anode, cathode, electrolyte, and separator. Generally, the positive and negative electrode materials of secondary batteries are composed of an active material, a binder, and a conductive material. Acetylene Black (AB) is utilized to enhance conductivity between active material particles or metal dust collectors, preventing the binder from acting as an insulator. However, when recycling waste batteries that have been subject to high usage, there is a risk of fire and explosion accidents, as accurately identifying the characteristics of Acetylene Black dust proves to be challenging. In this study, the lower explosion limit for Acetylene Black dust with an average particle size of 0.042 ㎛ was determined to be 153.64 mg/L using a Hartmann-type dust explosion device. Notably, the dust did not explode at values below 168 mg, rendering the lower explosion limit calculation unfeasible. Analysis of explosion delay times with varying electrode gaps revealed the shortest delay time at 3 mm, with a noticeable increase in delay times for gaps of 4 mm or greater. The findings offer fundamental data for fire and explosion prevention measures in Acetylene Black waste recycling processes via a predictive model for lower explosion limits and ignition delay time.