• Title/Summary/Keyword: Volatilization of lithium

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Synthesis of Li-rich Cathode Material with Spherical Shape and High Crystallinity by Using Flame Spray Pyrolysis (화염분무열분해법을 이용한 구형의 고결정성 리튬 과잉 양극재 제조)

  • Sung Nam Lim
    • New & Renewable Energy
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    • v.20 no.3
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    • pp.20-27
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    • 2024
  • A Li-rich cathode material, Li1.167Mn0.548Ni0.18Co0.105O2, with a spherical shape and high crystallinity, is prepared using flame spray pyrolysis. The post-heat treatment condition influences the properties of the prepared material, such as its structure, morphology, and chemical composition, and optimum performance is achieved at 900℃. Various excess Li contents (0-12 wt.%) are introduced in the precursor solution to compensate for volatilized Li during synthesis, bringing it close to the target composition. Compensation for volatilized Li enhances the electrochemical performance, i.e., the Li-compensated sample shows a good discharge capacity of 247 mAh g-1 at a current density of 20 mA g-1 in a potential window of 4.6-2.5 V. In addition, the prepared Li-rich cathode material supplemented with 9 wt.% of the Li source shows increased discharge capacity of 175 and 148 mAh g-1 at 200 and 400 mA g-1, respectively, compared with those of a bare sample (164 and 127 mAh g-1, respectively).

Secondary Phase Control of Lithium Ion-Substituted Potassium Niobate Ceramics via Stoichiometry Modification (화학양론 변화를 통한 리튬 이온 치환 니오브산 칼륨 세라믹의 이차상 제어 연구)

  • Tae Soo Yeo;Ju Hyeon Lee;Wook Jo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.37 no.5
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    • pp.533-540
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    • 2024
  • In line with the development of electronic devices and technologies, the demand for improving ferroelectric materials' performance is increasing. Since K0.5Na0.5NbO3 (KNN), an eco-friendly ferroelectric material that does not use lead and has a high Curie temperature, it is attracting attention to its usability as a high-temperature dielectric, and various studies are being conducted to increase performance. In a KNN having a perovskite structure, there was a simulation result that the KNN has higher spontaneous polarization when the A-site in which sodium ions exist is replaced with lithium ions. If the simulation results can be proven experimentally, the application range of KNN-based ferroelectric materials will increase. To this end, we tried to manufacture a K1-xLixNbO3 (KLN) with high electrical characteristics by fabricating niobium-deficient and potassium-excessive compositions, which attempt was made to solve the stoichiometry problem by volatilization and suppress secondary phases. If KLN's secondary phase suppression and relative permittivity improvement are successful, it will contribute to meeting the demand for developing electronic devices.