• Transactions of the Korean Society of Mechanical Engineers B
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• v.37 no.7
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• pp.665-667
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• 2013

Metal ions show various transitions in the cathode of a lithium-ion battery. The diffusion process of lithiumions and the phase transition in the cathode need to be thoroughly understood for the advanced design of an improved lithium-ion battery. Here, we employ a phase field model to simulate the diffusion of lithiumions and to study the phase transition in the cathode.

• Journal of the Korean institute of surface engineering
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• v.57 no.2
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• pp.57-70
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• 2024

Nickel-cobalt-manganese (NCM) lithium-ion batteries(LIBs) are increasingly prominent in the energy storage system due to their high energy density and cost-effectiveness. However, they face significant challenges, such as rapid capacity fading and structural instability during high-voltage operation cycles. Addressing these issues, numerous researchers have studied the enhancement of electrochemical performance through the coating of NCM cathode materials with substances like metal oxides, lithium composites, and polymers. Coating these cathode materials serves several critical functions: it acts as a protection barrier against electrolyte decomposition, mitigates the dissolution of transition metals, enhances the structural integrity of the electrode, and can even improve the ionic conductivity of the cathode. Ultimately, these improvements lead to better cycle stability, increased efficiency, and enhanced overall battery life, which are crucial for the advancement of NCM-based lithium-ion batteries in high-demand applications. So, this paper will review various cathode coating materials and examine the roles each plays in improving battery performance.

• Journal of Powder Materials
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• v.31 no.2
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• pp.163-168
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• 2024

As the demand for lithium-ion batteries for electric vehicles is increasing, it is important to recover valuable metals from waste lithium-ion batteries. In this study, the effects of gas flow rate and hydrogen partial pressure on hydrogen reduction of NCM-based lithium-ion battery cathode materials were investigated. As the gas flow rate and hydrogen partial pressure increased, the weight loss rate increased significantly from the beginning of the reaction due to the reduction of NiO and CoO by hydrogen. At 700 ℃ and hydrogen partial pressure above 0.5 atm, Ni and Li₂O were produced by hydrogen reduction. From the reduction product and Li recovery rate, the hydrogen reduction of NCM-based cathode materials was significantly affected by hydrogen partial pressure. The Li compounds recovered from the solution after water leaching of the reduction products were LiOH, LiOH·H₂O, and Li₂CO₃, with about 0.02 wt% Al as an impurity.

• Journal of Electrochemical Science and Technology
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• v.15 no.1
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• pp.168-177
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• 2024

Ni-rich cathode is one of the promising candidates for high-energy lithium-ion battery applications. Due to its specific capacity, easy industrialization, and good circulation ability, Ni-rich cathode materials have been widely used for lithium-ion batteries. However, due to the limitation of the co-precipitation method, including sewage pollution, and the instability of the long production cycles, developing a new efficient and environmentally friendly synthetic approach is critical. In this study, the Ni_0.91Co_0.06Mn_0.03CO₃ precursor powder was successfully synthesized by an efficient spray-drying method using carbonate compounds as a raw material. This Ni_0.91Co_0.06Mn_0.03CO₃ precursor was calcined by mixing with LiOH·H₂O (5 wt% excess) at 480℃ for 5 hours and then sintered at two different temperatures (780℃/800℃) for 15 hours under an oxygen atmosphere to complete the cathode active material preparation, which is a key component of lithium-ion batteries. As a result, LiNi_0.91Co_0.06Mn_0.03O₂ cathode active material powders were obtained successfully via a simple sintering process on the Ni_0.91Co_0.06Mn_0.03CO₃ precursor powder. Furthermore, the obtained LiNi_0.91Co_0.06Mn_0.03O₂ cathode active material powders were characterized. Overall, the material sintered at 780℃ shows superior electrochemical performance by delivering a discharge capacity of 190.76 mAh/g at 1^st cycle (0.1 C) and excellent capacity retention of 66.80% even after 50 cycles.

• Journal of Electrochemical Science and Technology
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• v.4 no.1
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• pp.27-33
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• 2013

The consequences of electrode density and thickness for electrochemical performance of lithium-ion cells are investigated using 2032-type coin half cells. While the cathode composition is maintained by 90:5:5 (wt.%) with $LiCoO_2$ active material, Super-P electric conductor and polyvinylidene fluoride polymeric binder, its density and thickness are independently controlled to 20, 35, 50 um and 1.5, 2.0, 2.5, 3.0, 3.5 g $cm^{-3}$, respectively, which are based on commercial lithium-ion battery cathode system. As the cathode thickness is increased in all densities, the rate capability and cycle life of lithium-ion cells become significantly worse. On the other hand, even though the cathode density shows similar behavior, its effect is not as high as the thickness in our experimental range. This trend is also investigated by cross-sectional morphology, porosity and electric conductivity of cathodes with different densities and thicknesses. This work suggests that the electrode density and thickness should be chosen properly and mentioned in detail in any kinds of research works.

• Journal of Electrochemical Science and Technology
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• v.11 no.3
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• pp.195-219
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• 2020

Today, rechargeable lithium-ion batteries are an essential portion of modern daily life. As a promising alternative to traditional energy storage systems, they possess various advantages. This review attempts to provide the reader with an indepth understanding of the working mechanisms, current technological progress, and scientific challenges for a wide variety of lithium-ion battery (LIB) electrode nanomaterials. Electrochemical thermodynamics and kinetics are the two main perspectives underlying our introduction, which aims to provide an informative foundation for the rational design of electrode materials. Moreover, both anode and cathode materials are clarified into several types, using some specific examples to demonstrate both their advantages and shortcomings, and some improvements are suggested as well. In addition, we summarize some recent research progress in the rational design and synthesis of nanostructured anode and cathode materials, together with their corresponding electrochemical performances. Based on all these discussions, potential directions for further development of LIBs are summarized and presented.

• Journal of the Korean Electrochemical Society
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• v.10 no.1
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• pp.31-35
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• 2007

In this review article, we are going to explain the recent development of lithium secondary batteries for a cellular phone. There are three kinds of rechargeable batteries for cellular phones such as nickel-cadmium, nickel-metal hydride, and lithium ion or lithium ion polymer. The lithium secondary battery is one of the most excellent battery in the point of view of energy density. It means very small and light one among same capacity batteries is the lithium secondary battery. The market volume of lithium secondary batteries increases steeply about 15% annually. The trend of R&D is focused on novel cathode materials including $LiFePO_4$, novel anode materials such as lithium titanate, silicon, and tin, elecrolytes, and safety insurance.

• Journal of Electrochemical Science and Technology
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• v.13 no.3
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• pp.362-368
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• 2022

The application of polymer composite electrolyte in all-solid-state lithium-sulfur battery (ASSLSBs) can guarantee high energy density and improve the interface contact between electrolyte and electrode, which has a broader application prospect. However, the inherent insulation of the sulfur-cathode leads to a low electron/ion transfer rate. Carbon materials with high electronic conductivity and electrolyte materials with high ionic conductivity are usually selected to improve the electron/ion conduction of the composite cathode. In this work, PEO-LiTFSI-LLZO composite polymer electrolyte (CPE) with high ionic conductivity was prepared. The ionic conductivity was 1.16×10^-4 and 7.26×10^-4 S cm^-1 at 20 and 60℃, respectively. Meanwhile, the composite sulfur cathode was prepared with Sulfur, reduced graphene oxide and composite polymer electrolyte slurry (S-rGO-CPEs). In addition to improving the ion conductivity in the cathode, CPEs also replaces the role of binder. The influence of different contents of CPEs in the cathode material on the performance of the constructed battery was investigated. The results show that the electrochemical performance of the all-solid-state lithium-sulfur battery is the best when the content of the composite electrolyte in the cathode is 40%. Under the condition of 0.2C and 45℃, the charging and discharging capacity of the first cycle is 923 mAh g^-1, and the retention capacity is 653 mAh g^-1 after 50 cycles.

• Journal of the Korean Electrochemical Society
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• v.11 no.3
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• pp.197-210
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• 2008

The cathode materials for lithium ion battery have been developed in accordance with the battery performance. $LiCoO_2$ initially adapted at lithium ion battery is going to be useful even at the charging voltage of 4.3 V by surface treatment or doping which drastically improved the performance of $LiCoO_2$. On the other hand, the complicate and multiple functions of recent electronic equipments required higher operational voltage and higher capacity than ever, which is going to be driving force for developing new cathode materials. Some of them are $LiNi_{1-x}{M_xO_2}$, $Li[Ni_{x}Mn_{y}Co_{z}]O_{2}$, $Li[{Ni}_{1/2}{Mn}_{1/2}]O_{2}$. Other new type of cathode materials having high safety is also developed to apply for HEV (hybrid electrical vehicle) and power tool applications. ${LiMn}_{2}{O}_{4}$ and $LiFePO_4$ are famous for highly stable material, which are expected to give contribution to make safer battery. In near future, the various materials having both capacity and safety will be developed by new technology, such as solid solution composite.

• KIPS Transactions on Software and Data Engineering
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• v.12 no.3
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• pp.133-140
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• 2023

The performance of lithium ion batteries depends on the usage environment and the combination ratio of cathode materials. In order to develop a high-performance lithium-ion battery, it is necessary to manufacture the battery and measure its performance while varying the cathode material ratio. However, it takes a lot of time and money to directly develop batteries and measure their performance for all combinations of variables. Therefore, research to predict the performance of a battery using an artificial intelligence model has been actively conducted. However, since measurement experiments were conducted with the same battery in the existing published battery data, the cathode material combination ratio was fixed and was not included as a data attribute. In this paper, we define a training data model required to develop an artificial intelligence model that can predict battery performance according to the combination ratio of cathode materials. We analyzed the factors that can affect the performance of lithium-ion batteries and defined the mass of each cathode material and battery usage environment (cycle, current, temperature, time) as input data and the battery power and capacity as target data. In the battery data in different experimental environments, each battery data maintained a unique pattern, and the battery classification model showed that each battery was classified with an error of about 2%.