• 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.

• 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.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07a
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• pp.134-137
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• 2004

새로운 리튬 2차전지용 양극활물질인 Li[NiMnCo]O2를 간단히 합성할 수 있는 방법과 Si의 doping에 의해 그 특성을 향상하였다. 원하는 당량비의 Li, Ni, Co, Mn의 nitrate를 고순도의 에탄올에 용해하고 여기에 Si의 원료물질로서 poly(methyl phenyl siloxane)을 원하는 양(전체 전이금속 이온의 $2{\sim}10\;mol%$)만큼 첨가한 후 약 30분 정도 교반하였다. 이 용액을 약 $70{\sim}80^{\circ}C$ 정도의 온도에서 고점도의 진흙 상태가 될 정도로 가열하고 $450{\sim}500^{\circ}C$의 온도에서 약 5시간 정도 열처리 하여 유기물이 없는 상태의 전구체를 제조하였다. 이 전구체를 분말형태로 분쇄하고 $600{\sim}650^{\circ}C$ 정도의 온도에서 3시간, $900{\sim}950^{\circ}C$ 정도의 온도에서 5시간 연속적으로 열처리 하여 최종 활물질을 제조하였다. 이렇게 제조된 활물질은 175mAh/g 정도의 높은 비용량을 나타내었으며 4.5V 충전 조건에도 우수한 수명특성을 나타내었다. Si이 doping되지 않은 활물질에 비해 Si이 doping된 물질은 율특성, 수명특성에서 보다 우수한 특성을 나타내었는데 이것은 층상구조 활물질의 격자상수 증가와 impedance 증가 억제에 기인한 것으로 분석되었다.

• 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.

• 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.

• Journal of the Korean Electrochemical Society
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• v.6 no.4
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• pp.261-265
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• 2003

The heat treatment process of thin film microbatteries manufacturing processes has several Problems. This study, without heat treatment, considered the characteristics of $LiCoO_2$ thin films deposited by bais sputtering method inducing the structural change of the thin film. The properties of deposited $LiCoO_2$ thin films such as crystal structure, morphology, and discharge capacity were observed by various analysis methods. Among $LiCoO_2$ thin films deposited by substrate bias $voltage(V_b)$, the one deposited by substrate bias voltage of -50V had the highest initial discharge capacity of about $60{\mu}Ah/cm^2{\mu}m.$ We confirmed that $LiCoO_2$ thin film could be used as cathode material of lithium thin film microbatteries without annealing.

• Ceramist
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• v.13 no.5
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• pp.32-38
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• 2010

• Proceedings of the KIPE Conference
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• 2017.11a
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• pp.161-162
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• 2017

배터리 팩에 사용되는 리튬이온 배터리는 셀의 양극활물질에 따라 특성이 다르다. 배터리 팩의 효율적 운용을 위해 단위 셀간 편차를 최소화 하는 것이 필요하다. 본 논문에서는 양극활물질이 다른 고출력 및 고용량 리튬이온 배터리 세 종류를 선정하여 IR 및 OCV를 측정하고, 통계적 분석 기반 셀 스크리닝을 진행하여 결과를 비교 분석하였다.

• Ceramist
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• v.19 no.3
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• pp.21-25
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• 2016

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.11a
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• pp.118-118
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• 2003