• Title/Summary/Keyword: Na ion battery

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Research Trends of Cathode Materials for Next Generation Lithium Ion Battery (리튬이온전지(Lithium Ion Battery) 양극 물질 연구동향)

  • Na, Sung Min;Park, Hyun Gyu;Kim, Sun Wook;Cho, Hyuk Hee;Park, Kwanggjin
    • Prospectives of Industrial Chemistry
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    • v.23 no.1
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    • pp.3-17
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    • 2020
  • 리튬이온전지(LIB)는 기존의 다른 이차전지와 다른 확실한 몇 가지 장점이 있다. 높은 작동 전압과 높은 에너지 밀도, 긴 수명, 그리고 낮은 자체 방전 속도이다. 이러한 장점으로 모바일 제품에서부터 전기 자동차(battery electric vehicle, BEV), 최근에는 전기저장장치(energy storage system, ESS)까지 다양한 분야에서 사용되고 있다. 하지만 사용 범위가 증가함에 따라 높은 안정성을 가지며 더 큰 에너지 용량을 나타내는 리튬이온전지에 대한 요구가 점점 더 커지게 되었다. 리튬이온전지의 용량 증가는 전지의 설계보다는 양극 및 음극 재료, 분리막 및 전해질과 같은 주요 전지 재료의 기술적 진보에 달려 있다. 주요 전지 소재 중에 전지의 성능에 가장 큰 영향을 미치는 것은 전지 반응에 의한 과전압과 가격이 가장 비싼 양극이다. 본 기획 특집에서는 리튬이차전지의 성능에 가장 큰 영향을 미치는 양극 물질의 종류와 향후 연구동향에 대해서 소개하고자 한다. 양극 물질의 발전 방향, 안정성과 용량 증대를 위해서 최근 연구되고 있는 방향에 대해서 자세하게 소개한다.

Mechanisms of Na adsorption on graphene and graphene oxide: density functional theory approach

  • Moon, Hye Sook;Lee, Ji Hye;Kwon, Soonchul;Kim, Il Tae;Lee, Seung Geol
    • Carbon letters
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    • v.16 no.2
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    • pp.116-120
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    • 2015
  • We investigated the adsorption of Na on graphene and graphene oxide, which are used as anode materials in sodium ion batteries, using density functional theory. The adsorption energy for Na on graphene was -0.507 eV at the hollow sites, implying that adsorption was favorable. In the case of graphene oxide, Na atoms were separately adsorbed on the epoxide and hydroxyl functional groups. The adsorption of Na on graphene oxide-epoxide (adsorption energy of -1.024 eV) was found to be stronger than the adsorption of Na on pristine graphene. However, the adsorption of Na on graphene oxide-hydroxyl resulted in the generation of NaOH as a by-product. Using density of states (DOS) calculations, we found that the DOS of the Na-adsorbed graphene was shifted down more than that of the Na-adsorbed graphene oxide-epoxide. In addition, the intensity of the DOS around the Fermi level for the Na-adsorbed graphene was higher than that for the Na-adsorbed graphene oxide-epoxide.

Leaching of Cathodic Active Materials from Spent Lithium Ion Battery (폐리튬이온전지로부터 분리한 양극활물질의 침출)

  • 이철경;김태현
    • Resources Recycling
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    • v.9 no.4
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    • pp.37-43
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    • 2000
  • Leaching of $LiCoO_2$ as a cathodic active materials for recovering Li and Co from spent lithium ion battery was investigated in terms of reaction variables. At the optimum condition determined in the previous work, Li and Co in a $H_2SO_4$ and $HNO_3$ solution were dissolved 70~80% and 40%, respectively. Li and Co were leached over 95% with the addition of a reductant such as $Na_2S_2O_3$ or $H_2O_2$. This behavior is probably due to the reduction of $Co^{3+}$ to $Co^{2+}$. Leaching of $LiCoCo_2$ powder obtained by calcination of an electrode materials from spent batteries was also carried out. Leaching efficiency of Li and Co were over 99% at the optimum condition with $H_2O_2$ addition of 1.7 vol.%. It seems to be due to the activation of $LiCoO_2$ by repeated charging and discharging or an imperfect crystal structure by deintercalation of Li.

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A Mechanism Study on Formation and Reduction of Residual Li of High Nickel Cathode for Lithium-ion Batteries (층상계 하이니켈 양극재의 잔류 리튬 생성 및 저감 메커니즘 연구)

  • MinWook, Pin;Beom Tak, Na;Tae Eun, Hong;Youngjin, Kim
    • Journal of Industrial Technology
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    • v.42 no.1
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    • pp.7-12
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    • 2022
  • High nickel layered oxide cathodes are gaining increasing attention for lithium-ion batteries due to their higher energy density and lower cost compared to LiCoO2. However, they suffer from the formation of residual lithium on the surface in the form of LiOH and Li2CO3 on exposure to ambient air. The residual lithium causes notorious issues, such as slurry gelation during electrode preparation and gas evolution during cell cycling. In this review, we investigate the residual lithium issues through its impact on cathode slurry instability based on deformed polyvinylidene fluoride (PVdF) as well as its formation and reduction mechanism in terms of inherently off-stoichiometric synthesis of high nickel cathodes. Additionally, new analysis method with anhydrous methanol was introduced to exclude Li+/H+ exchange effect during sample preparation with distilled water. We hope that this review would contribute to encouraging the academic efforts to consider practical aspects and mitigation in global high-energy-density lithium-ion battery manufacturers.

Electrochemical Performances of Lithium-ion Polymer Battery with Polyoxyalkylene Glycol Acrylate-based Gel Polymer Electrolyte (Polyoxyalkylene Glycol Acrylate기 Gel Polymer Electrolyte를 적용한 리튬이온폴리머전지의 전기화학적 특성)

  • Kim, Hyun-Soo;Kim, Sung-Il;Na, Seong-Hwan;Moon, Seong-In
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.18 no.2
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    • pp.142-147
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    • 2005
  • In this work, a gel polymer electrolyte (GPE) was prepared using polyoxyalkylene glycol acrylate (POAGA) as a macromonomer LiCoO$_2$/GPE/graphite cells were prepared and their electrochemical properties were evaluated at various current densities and temperatures. The ionic conductivity of the GPE was more than 6.2${\times}$10$^{-3}$ S$.$$cm^{-1}$ / at room temperature. The GPE had good electrochemical stability up to 4.5 V vs. Li/Li$^{+}$. POAGA-based cells were showed good electrochemical performances such as rate capability, low-temperature performance, and cycleability. The cells, also, passed a safety test such as the overcharge and nail-penetration test.t.

Electrochemical characteristics of active carbon prepared by chemical activation for anode of lithium ion battery (이차전지 음극용 화학적 활성화법으로 제조된 활성탄의 전기화학적 특성)

  • Lee, Ho-Yong;Kim, Tae-Yeong;Lee, Jong-Dae
    • Journal of the Korean Applied Science and Technology
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    • v.32 no.3
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    • pp.480-487
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    • 2015
  • In this study, several kinds of active carbons with high specific surface area and micro pore structure were prepared from the coconut shell charcoal using chemical activation method. The physical property of prepared active carbon was investigated by experimental variables such as activating chemical agents to char coal ratio, flow rate of inert gas and temperature. It was shown that chemical activation with KOH and NaOH was successfully able to make active carbons with high surface area of $1900{\sim}2500m^2/g$ and mean pore size of 1.85~2.32 nm. The coin cell using water-based binder in the electrolyte of LiPF6 dissolved in mixed organic solvents (EC:DMC:EMC=1:1:1 vol%) showed better capacity than that of oil-based binder. Also, it was found that the coin cell of water-based binder shows an improved cycling performance and coulombic efficiency.

Preparation and Electrochemical Performances Comparison of Carbon and Hydrogel Electrocatalysts for Seawater Battery (해수 전지용 탄소계 촉매와 Hydrogel 촉매의 제조 및 이들의 전기화학적 특성 비교)

  • Kim, Kyoungho;Na, Young Soo;Lee, Man Sung
    • Journal of the Korean Electrochemical Society
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    • v.21 no.4
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    • pp.61-67
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    • 2018
  • As emerging the new electric devices, the commercial lithium ion batteries have faced with various challenges. In this regard, many efforts to solve challenges have been tried. In order to solve the above problems in terms of development of a new secondary battery, we successfully demonstrated the two electrocatalysts, such as MCWB and PPY hydrogel, PPY hydrogel and MCWB showed typical H3-type BET isotherm, indicating that micro- and mesopores existed. Especially, in terms of voltage efficiency at the first cycle, PPY hydrogel was higher than that of MCWB, but lower than that of PtC. More interestingly, the PPY hygrogel based seawater battery exhibited charge-discharge reversibility during 20 cycles, and the voltage efficiencies ranged from 70.32 % to 77.35 % in cyclic performance test.

A Study on the Separation of Cadmium from Waste Ni-Cd Secondary Batteries by Ion Substitution Reaction (이온치환 반응을 이용한 니켈-카드뮴 폐이차전지에서 카드뮴의 분리에 대한 연구)

  • Kim, Dae-Weon;Park, Il-Jeong;Ahn, Nak-Kyoon;Jeong, Hang-Chul;Jung, Soo-Hoon;Choi, Joong-Yup;Yang, Dae-Hoon
    • Resources Recycling
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    • v.27 no.4
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    • pp.36-43
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    • 2018
  • In order to recycle waste nickel-cadmium batteries, cadmium was selectively removed by ion substitution reaction so that cadmium and nickel could be separated efficiently. The electrode powder obtained by crushing the electrode in the waste nickelcadmium battery was leached with sulfuric acid. The cadmium in the nickel-cadmium solution was precipitated with cadmium sulfide by the addition of sodium sulfide. Ion substitution experiments were carried out under various conditions. At the optimum condition with pH = -0.1 and $Na_2S/Cd=2.3$ at room temperature, the residual Cd in the solution was about 100 ppm, and most of it was precipitated with CdS.

Synthesis of LiMn2O4 Powders Using Li-Ion Secondary Battery by SHS Process (SHS합성법에 의한 리튬이온이차전지용 정극활물질 LiMn2O4 의 제조)

  • Jang, Chang-Hyun;Nersisyan, Hayk;Kim, Jung-Han;Won, Chang-Whan
    • Journal of the Korean Ceramic Society
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    • v.42 no.7 s.278
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    • pp.503-508
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    • 2005
  • A simple and effective method for the synthesis of LiMn$_{2}$O$_{4}$ powder as a cathode material for lithium secondary battery is reported. Micrometer size LiMn$_{2}$O$_{4}$ was prepared by combustion synthesis technique employing initial mixture of l.l LiNO$_{3}$ -1.3Mn-0.7MnO$_{2}$-1NaCl composition. Parametric study of the combustion process including molar ratio of Mn/MnO$_{2}$ and NaCl concentration were carried out under air atmosphere. The combustion products obtained were additionally heat treated at the temperature 900$^{\circ}C$ and the washed by distilled water. The results of charging-discharging characteristics revealed that LiMn$_{2}$O$_{4}$ cell synthesized in the presence of NaCl had a high capacity and much better reversibility than one formed without NaCl An approximate chemical mechanism for LiMn$_{2}$O$_{4}$ formation is proposed.