• Title, Summary, Keyword: 양극물질

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Recovery of Rare Metals from the Waste Secondary Lithium Ion Battery Cathode Active Materials Using Lactic Acid and Oxalic acid (젖산과 옥살산을 이용한 폐 이차 리튬이온 전지 양극 활물질로부터 희유금속들의 회수)

  • Kim, Younjung;Han, Ji Sun;Choi, Sik Young;Oh, In-Gyung;Hong, Yong Pyo;Ryoo, Keon Sang
    • Journal of the Korean Chemical Society
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    • v.63 no.6
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    • pp.446-452
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    • 2019
  • We have developed a method that can leach Co, Mn, and Ni in the cathode active material safely using lactic acid. When cathode active material was leached by lactic acid, lactic acid showed the highest efficiency at 2 N than 1 N and above 4 N concentration. When the cathode active material was added incrementally into the solution of lactic acid, the maximum solubility was 30 g/L at 2 N concentration. Oxalic acid was added in the solution of lactic acid and it showed that rare metals represent the most economical recovery efficiency at 4 g/L. Based on this study, it was found that the optimal condition for recovery of rare metals from cathode active material is oxalic acid : cathode active material = 7 : 1 as a ratio of weight. In addition, it was observed that the precipitate produced by oxalic acid is a polynuclear crystalline material bonded with 3 components of Co, Ni, and Mn.

A study on the synthesis and improvement of electrochemical properties of olivine-type phosphate cathode materials for lithium rechargeable batteries by mechanical alloying (기계적 합금화법에 의한 리튬 이차전지용 phosphate계 양극물질의 제조 및 전기화학적 특성 향상에 관한 연구)

  • 김철우;권상준;정운태;이경섭
    • Proceedings of the Materials Research Society of Korea Conference
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    • pp.216-216
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    • 2003
  • 현재 상용화되어 있는 리튬 이차전지용 양극재료로는 비교적 작동전압이 높은 층상 암염구조(LiCoO$_2$, LiNiO$_2$) 및 Spinet계(LiMn$_2$O$_4$) 전이금속 산화물이 대부분 이용되고 있다 하지만 LiCoO$_2$나 LiNiO$_2$ 같은 상용화 물질은 비교적 높은 비용과, 강한 독성 때문에 많은 문제점을 가지고 있다. 또 Spinel(LiMn$_2$O$_4$)는 낮은 비용과 환경친화적인 장점에도 불구하고 Jahn-Teller 변형과 관련된 구조적 변형이 심각하기 때문에 사이클시 비가역적인 용량의 감소가 심각하다. 이러한 관점에서 전이금속보다 그 양이 풍부하고 저렴할 뿐만 아니라 독성이 없는 Olivine 구조 (LiFePO$_4$)를 갖는 phosphate계 화합물에 관심을 가지게 되었다. LiFePO$_4$는 리튬 음극과 3.4V의 방전전압을 나타내며, 170mAh/g의 이론용량을 가지고 있어, Fe-base의 장점은 물론 안정적인 결정구조 및 현재 상용화된 재료들과 비슷한 에너지 밀도를 가진다. 따라서 본 연구에서는 양극물질의 기존 두 제조법인 고상반응법과 sol-gel법으로 대표되는 제조법의 단점을 상호 보완될 수 있다고 판단되는 기계적 합금화법(Mechanical Alloying, MA)공정을 도입하여 초미세립 분말 제조에 초점을 맞추어 Olivine phosphate계 양극물질의 제조 및 전기화학적 특성을 연구하였다.

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Fabrication of Superhydrophobic TiO2 Films without Color Alternation (색 변화 없는 초소수성 타이타늄 산화막 제조)

  • Kim, Seon-Gyu;Choe, Jin-Seop
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • pp.339-339
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    • 2015
  • 타이타늄을 2단계로 양극산화하여 색을 유지하며 표면에 튜브형태를 갖는 산화막을 제조하였다. 타이타늄을 양극산화 시, 전해질 농도, 양극산화 전압, 시간 등에 따라 다양한 색을 띄게 되는데, 기름기 등의 오염물질로 인한 색 변화, 내 지문성 등의 문제가 유발된다. 이에 타이타늄을 양극산화하여 나노튜브를 성장시킨 후, 기존 산화막 제조와 같은 조건으로 다시 양극산화하였다. 그 결과 기존 barrier 형태의 산화막 색이 구현되면서, 표면의 돌기형태에 따른 접촉각이 변화하게 되었다.

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Safe Decomposition of the Vehicle Waste Battery Module and Development of Separation Process of Cathode Active Material from Aluminum Thin Film (자동차용 폐 리튬 이차전지 모듈의 안정적 해체와 알루미늄 박막으로부터 양극활물질의 분리공정 개발)

  • Kim, Younjung;Oh, In-Gyung;Hong, Yong Pyo;Ryoo, Keon Sang
    • Journal of the Korean Chemical Society
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    • v.63 no.6
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    • pp.440-445
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    • 2019
  • It has developed a method that can recover efficiently the reproducible resources from the vehicle waste lithium second battery module. Module cell consists of copper thin film, aluminum thin film and diaphragm made with polymer between these thin films. Cell was disassembled completely without any damage in glove box and through several steps. Preferentially, cathode active material was separated from aluminum thin film at heat treatment of 400 ℃. The retrieved cathode active material was then obtained as high purity after calcining at 800 ℃ to remove residual carbon. Based on this study, it was found that rare metals such as Co, Ni, Mn and Li made up of cathode active material could recover above 80% from aluminum thin film.

Synthesis and Electrochemical Properties of Zn and Al added LiNi0.85Co0.15O2 Cathode Materials (Zn와 Al을 첨가한 LiNi0.85Co0.15O2 양극활물질의 제조 및 전기화학적 특성평가)

  • Kim, Su-Jin;Seo, Jin-Seong;Na, Byung-Ki
    • Korean Chemical Engineering Research
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    • v.59 no.1
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    • pp.42-48
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    • 2021
  • Zn and Al added LiNi0.85Co0.15O2 cathode materials were synthesized to improve electrochemical properties and thermal stability using a solid-state route. Crystal structure, particle size and surface shape of the synthesized cathode materials was measured using XRD (X-ray diffraction) and SEM (scanning electron microscopy). CV (cyclic voltammetry), first charge-discharge profiles, rate capability, and cycle life were measured using battery cycler (Maccor, series 4000). Strong binding energy of Al-O bond enhanced structure stability of cathode material. Electrochemical properties were improved by preventing cation mixing between Li+ and Ni2+. Large ion radius of Zn+ increased lattice parameter of NC cathode material, which meant unit-cell volume was expanded. NCZA25 showed 80% of capacity retention at 0.5 C-rate during 100 cycles, which was 12% higher than that of NC cathode. The discharge capacity of NCZA25 showed 104 mAh/g at 5 C-rate. NCZA25 achieved 36 mAh/g more capacity than that of NC cathod. NCZA25 cathode material showed excellent rate capability and cycling performance.

First-Principles Investigation of the Surface Properties of LiNiO2 as Cathode Material for Lithium-ion Batteries (제일원리계산을 이용한 리튬이차전지 양극활물질 LiNiO2의 표면 특성에 관한 연구)

  • Choi, Heesung;Lee, Maeng-Eun
    • Journal of the Korean Electrochemical Society
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    • v.16 no.3
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    • pp.169-176
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    • 2013
  • Solid state lithium oxide compounds of layered structure, which has high stability of structure, are mainly used as the cathode materials in lithium-ion batteries (LIBs). Recently, the investigation of Solid Electrolyte Interphase (SEI) between active materials and electrolyte has been focusing to improve the performance of lithium-ion batteries. For the investigation of the SEI, the study of surface properties of cathode materials and anode materials is also required in advance. $LiNiO_2$ and $LiCoO_2$ are very similar layered structure of cathode active materials and representative solid state lithium oxide compounds in LIBs. Various experimental and theoretical studies have been doing for $LiCoO_2$. The theoretical investigation of $LiNiO_2$ is not sufficient, however, even if experimental studies of $LiNiO_2$ are enough. In this study, the surface energies of nine facets of $LiNiO_2$ crystal facets were calculated by Density Functional Theory. In XRD data of $LiNiO_2$, (003), (104), (101), et al. facets are main surfaces in order. However, the results of calculation are different with XRD data. Thus, both (104) and (101) facets, which are energetically stable and measured in XRD, are mainly exposed in the surface of $LiNiO_2$ and it is expected that intercalation and de-intercalation of Li-ion will be affected by them.