• Title/Summary/Keyword: Lithium oxide

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탄산리튬으로부터 수산화리튬 전환을 위하여 탄산리튬의 열분해에 대한 연구 (A study on the pyrolysis of lithium carbonate for conversion of lithium hydroxide from lithium carbonate)

  • 박재은;박민화;서형준;김태성;김대원;김보람;최희락
    • 한국결정성장학회지
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    • 제31권2호
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    • pp.89-95
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    • 2021
  • 현재 리튬이온 배터리에 사용되는 고니켈계 양극재의 수요 증대에 따라 수산화리튬(LiOH) 제조 연구가 활발히 진행되고 있다. 본 논문에서는 탄산리튬(Li2CO3)으로부터 수산화리튬의 제조를 위하여, 탄산리튬의 열분해를 통한 산화리튬(Li2O)의 전환 공정에 대해 연구하였다. 열처리 시 탄산리튬과 알루미나, 석영 그리고 흑연 도가니 사용에 따른 반응 메커니즘을 확인하였으며, 흑연 도가니를 사용했을 경우 온전한 산화리튬 분말을 얻었다. TG 분석 결과를 바탕으로 열처리 온도를 700℃, 900℃ 그리고 1100℃로 설정하였으며 유지시간 및 분위기를 제어하여 시약급 탄산리튬의 열처리를 진행하였다. XRD 분석 결과, 제조된 산화리튬은 질소 분위기에서 1시간 동안 1100℃의 온도로 열처리를 하였을 때 높은 결정성을 보였다. 또한 수산화리튬으로 전환하기 위해 시약급 산화리튬을 100℃에서 수반응하였다. XRD 분석을 통해 수산화리튬(LiOH)과 수산화리튬 일수화물(LiOH·H2O)이 생성됨을 확인하였다.

습식혼합에 의한 리튬망간 산화물의 합성과 리튬이온 제거특성 (Synthesis of Lithium Manganese Oxide by Wet Mixing and its Removal Characteristic of Lithium Ion)

  • 유해나;이동환;이민규
    • 청정기술
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    • 제19권4호
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    • pp.446-452
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    • 2013
  • 본 연구에서는 탄산리튬과 탄산망간을 사용하여 습식혼합방법으로 스피넬 리튬망간 산화물(LMO)을 합성하였다. 합성한 리튬망간 산화물의 물리적인 특성은 X-선 회절 분석기(X-ray diffraction, XRD)와 주사전자현미경(scanning electron microscopy, SEM) 사용하여 분석하였다. 회분식 실험을 통해 LMO의 리튬이온에 대한 흡착특성을 살펴보았다. Langmuir 흡착 등온식으로부터 구한 리튬의 최대흡착량은 27.21 mg/g였다. LMO는 뛰어난 리튬 이온체의 특성을 가지고 있었으며, $Ca^{2+}$ < $K^+$ < $Na^+$ < $Mg^{2+}$ < $Li^+$ 순서로 분배계수($K_d$)가 나타나 해수로부터 리튬을 회수하는데 용이할 것으로 사료된다.

Equilibrium and kinetic studies of an electro-assisted lithium recovery system using lithium manganese oxide adsorbent material

  • Lee, Dong-Hee;Ryu, Taegong;Shin, Junho;Kim, Young Ho
    • Carbon letters
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    • 제28권
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    • pp.87-95
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    • 2018
  • This study examined the influence of operating parameters on the electrosorptive recovery system of lithium ions from aqueous solutions using a spinel-type lithium manganese oxide adsorbent electrode and investigated the electrosorption kinetics and isotherms. The results revealed that the electrosorption data of lithium ions from the lithium containing aqueous solution were well-fitted to the Langmuir isotherm at electrical potentials lower than -0.4 V and to the Freundlich isotherm at electrical potentials higher than -0.4 V. This result may due to the formation of a thicker electrical double layer on the surface of the electrode at higher electrical potentials. The results showed that the electrosorption reached equilibrium within 200 min under an electrical potential of -1.0 V, and the pseudo-second-order kinetic model was correlated with the experimental data. Moreover, the adsorption of lithium ions was dependent on pH and temperature, and the results indicate that higher pH values and lower temperatures are more suitable for the electrosorptive adsorption of lithium ions from aqueous solutions. Thermodynamic results showed that the calculated activation energy of $22.61kJ\;mol^{-1}$ during the electrosorption of lithium ions onto the adsorbent electrode was primarily controlled by a physical adsorption process. The recovery of adsorbed lithium ions from the adsorbent electrode reached the desorption equilibrium within 200 min under reverse electrical potential of 3.5 V.

수중의 리튬 이온 회수를 위한 새로운 흡착제인 SAN-LMO 비드의 제조 (Adsorption Characteristics of Lithium Ions from Aqueous Solution using a Novel Adsorbent SAN-LMO Beads)

  • 감상규;박정민;이민규
    • 한국환경과학회지
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    • 제24권5호
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    • pp.641-646
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    • 2015
  • In order to recover lithium ions from aqueous solution, a novel SAN-LMO beads were prepared by immobilizing lithium manganese oxide (LMO) with styrene acrylonitrile copolymers (SAN). The optimum condition for synthesis of SAN-LMO beads was 5 g of LMO and 3 g of SAN content. The characterization of the prepared SAN-LMO beads by SEM and XRD were confirmed that LMO was immobilized in SAN-LMO beads. The removal and the distribution coefficient of lithium ions decreased with increasing lithium ion concentration and solution pH. Even when the prepared SAN-LMO beads were reused 5 times, the leakage of LMO and the damage of SAN-LMO beads was not observed.

Sol-Gel법을 통한 리튬 기반 전해질에 적합한 니켈 산화물 박막의 제조와 리튬 기반 전해질에서의 전기변색 특성 (Fabrication of Nickel Oxide Thin Film for Lithium Based Electrolyte by Sol-Gel Method and Electrochromic Properties in Lithium Based Electrolyte)

  • 박선하;유성종;임주완;윤성욱;차인영;성영은
    • 전기화학회지
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    • 제12권3호
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    • pp.251-257
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    • 2009
  • In this study, we fabricated nickel oxide thin film for lithium based electrolyte using sol-gel method. This film was deposited by dip-coating method with mixed solvent of DameH (N,N-dimethylaminoethanol) and DI water. As changing the ratio between DmaeH and DI water, nickel oxide thin film was presented in different charge density and optical transmittance because they were shown various thickness. It was accounted for changing viscosity and density by the ratio of DmaeH and DI water. The thin film synthesized with 1 : 1 ratio of DmaeH and DI water was expressed best electrochromic performance in lithium based electrolyte, because of thick thickness but porous structures.

The Preparation of Non-aqueous Supercapacitors with Lithium Transition-Metal Oxide/Activated Carbon Composite Positive Electrodes

  • Kim, Kyoung-Ho;Kim, Min-Soo;Yeu, Tae-Whan
    • Bulletin of the Korean Chemical Society
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    • 제31권11호
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    • pp.3183-3189
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    • 2010
  • In order to increase the specific capacitance and energy density of supercapacitors, non-aqueous supercapacitors were prepared using lithium transition-metal oxides and activated carbons as active materials. The electrochemical properties were analyzed in terms of the content of lithium transition-metal oxides. The results of cyclic voltammetry and AC-impedance analyses showed that the pseudocapacitance may stem from the synergistic contributions of capacitive and faradic effects; the former is due to the electric double layer which is prepared in the interface of activated carbon and organic electrolyte, and the latter is due to the intercalation of lithium ($Li^+$) ions. The specific capacitance and energy density of a supercapacitor improved as the lithium transition-metal oxides content increased, showing 60% increase compared to those of supercapacitor using a pure activated carbon positive electrode.

나노 구조를 가지는 다공성 주석 산화물의 전기화학적 특성 (Electrochemical Characterization of Anodic Tin Oxides with Nano-Porous Structure)

  • 이재욱;박수진;신헌철
    • 한국재료학회지
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    • 제21권1호
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    • pp.21-27
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    • 2011
  • A nano-porous structure of tin oxide was prepared using an anodic oxidation process and the sample's electrochemical properties were evaluated for application as an anode in a rechargeable lithium battery. Microscopic images of the as-anodized sample indicated that it has a nano-porous structure with an average pore size of several tens of nanometers and a pore wall size of about 10 nanometers; the structural/compositional analyses proved that it is amorphous stannous oxide (SnO). The powder form of the as-anodized specimen was satisfactorily lithiated and delithiated as the anode in a lithium battery. Furthermore, it showed high initial reversible capacity and superior rate performance when compared to previous fabrication attempts. Its excellent electrode performance is probably due to the effective alleviation of strain arising from a cycling-induced large volume change and the short diffusion length of lithium through the nano-structured sample. To further enhance the rate performance, the attempt was made to create porous tin oxide film on copper substrate by anodizing the electrodeposited tin. Nevertheless, the full anodization of tin film on a copper substrate led to the mechanical disintegration of the anodic tin oxide, due most likely to the vigorous gas evolution and the surface oxidation of copper substrate. The adhesion of anodic tin oxide to the substrate, together with the initial reversibility and cycling stability, needs to be further improved for its application to high-power electrode materials in lithium batteries.

Novel Synthesis Method and Electrochemical Characteristics of Lithium Titanium Oxide as Anode Material for Lithium Secondary Battery

  • Kim Han-Joo;Park Soo-Gil
    • KIEE International Transactions on Electrophysics and Applications
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    • 제5C권3호
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    • pp.119-123
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    • 2005
  • Lithium titanium oxide as anode material for energy storage prepared by novel synthesis method. Li$_{4}$Ti$_{5}$O$_{12}$ based spinel-framework structures are of great interest material for lithium-ion batteries. We describe here Li$_{4}$Ti$_{5}$O$_{12}$ a zero-strain insertion material was prepared by novel sol-gel method and by high energy ball milling (HEBM) of precursor to from nanocrystalline phases. According to the X-ray diffraction and scanning electron microscopy analysis, uniformly distributed Li$_{4}$ Ti$_{5}$O$_{12}$ particles with grain sizes of 100nm were synthesized. Lithium cells, consisting of Li$_{4}$ Ti$_{5}$O$_{12}$ anode and lithium cathode showed the 173 mAh/g in the range of 1.0 $\~$ 3.0 V. Furthermore, the crystalline structure of Li$_{4}$ Ti$_{5}$O$_{12}$ didn't transform during the lithium intercalation and deintercalation process.

Cobalt Oxide Nanorods Prepared by a Template-Free Method for Lithium Battery Application

  • Kim, Seong-Jun;Kim, Eun-Ji;Liu, Meilin;Shin, Heon-Cheol
    • Journal of Electrochemical Science and Technology
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    • 제7권3호
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    • pp.206-213
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    • 2016
  • Transition metal oxide-based electrodes for lithium ion batteries have recently attracted much attention because of their high theoretical capacity. Here we report the electrochemical behavior of cobalt oxide nanorods as anodes, prepared by a template-free, one-step electrochemical deposition of cobalt nanorods, followed by an oxidation process. The as-deposited cobalt has a slightly convex columnar structure, and controlled thermal oxidation produces cobalt oxides of different Co/O ratios, while the original shape is largely preserved. As an anode in a rechargeable lithium battery, the Co/O ratio has a strong effect on initial capacity and cycling stability. In particular, the one-dimensional Co@CoxOy core shell structure obtained from a mild heat-treatment results in superior cycling stability.