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Morphological and Electrochemical Properties of ZnMn2O4 Nanopowders and Their Aggregated Microspheres Prepared by Simple Spray Drying Process

  • Gi Dae Park (Department of Advanced Materials Engineering, Chungbuk National University) ;
  • Yun Chan Kang (Department of Materials Science and Engineering, Korea University) ;
  • Jung Sang Cho (Department of Engineering Chemistry, Chungbuk National University)
  • 투고 : 2022.01.21
  • 심사 : 2022.02.15
  • 발행 : 20220000

초록

Phase-pure ZnMn2O4 nanopowders and their aggregated microsphere powders for use as anode material in lithium-ion batteries were obtained by a simple spray drying process using zinc and manganese salts as precursors, followed by citric acid post-annealing at different temperatures. X-ray diffraction (XRD) analysis indicated that phase-pure ZnMn2O4 powders were obtained even at a low post-annealing temperature of 400 ℃. The post-annealed powders were transformed into nanopowders by simple milling process, using agate mortar. The mean particle sizes of the ZnMn2O4 powders post-treated at 600 and 800 ℃ were found to be 43 and 85 nm, respectively, as determined by TEM observation. To provide practical utilization, the nanopowders were transformed into aggregated microspheres consisting of ZnMn2O4 nanoparticles by a second spray drying process. Based on the systematic analysis, the optimum post-annealing temperature required to obtain ZnMn2O4 nanopowders with high capacity and good cycle performance was found to be 800 ℃. Moreover, aggregated ZnMn2O4 microsphere showed improved cycle stability. The discharge capacities of the aggregated microsphere consisting of ZnMn2O4 nanoparticles post-treated at 800 ℃ were 1235, 821, and 687 mA h g-1 for the 1st, 2nd, and 100th cycles at a high current density of 2.0 A g-1, respectively. The capacity retention measured after the second cycle was 84%.

키워드

과제정보

This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIP) (NRF-2019R1I1A1A01060407).