Design and Synthesis of Spherical Multicomponent Aggregates Composed of Core–Shell,Yolk–Shell,and Hollow Nanospheres and Their Lithium‐Ion Storage Performances |
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Authors: | Gi Dae Park Yun Chan Kang |
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Affiliation: | Department of Materials Science and Engineering, Korea University, Seongbuk‐Gu, Seoul, Republic of Korea |
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Abstract: | Micrometer‐sized spherical aggregates of Sn and Co components containing core–shell, yolk–shell, hollow nanospheres are synthesized by applying nanoscale Kirkendall diffusion in the large‐scale spray drying process. The Sn2Co3–Co3SnC0.7–C composite microspheres uniformly dispersed with Sn2Co3–Co3SnC0.7 mixed nanocrystals are formed by the first‐step reduction of spray‐dried precursor powders at 900 °C. The second‐step oxidation process transforms the Sn2Co3–Co3SnC0.7–C composite into the porous microsphere composed of Sn–Sn2Co3@CoSnO3–Co3O4 core–shell, Sn–Sn2Co3@CoSnO3–Co3O4 yolk–shell, and CoSnO3–Co3O4 hollow nanospheres at 300, 400, and 500 °C, respectively. The discharge capacity of the microspheres with Sn–Sn2Co3@CoSnO3–Co3O4 core–shell, Sn‐Sn2Co3@CoSnO3–Co3O4 yolk–shell, and CoSnO3–Co3O4 hollow nanospheres for the 200th cycle at a current density of 1 A g?1 is 1265, 987, and 569 mA h g?1, respectively. The ultrafine primary nanoparticles with a core–shell structure improve the structural stability of the porous‐structured microspheres during repeated lithium insertion and desertion processes. The porous Sn–Sn2Co3@CoSnO3–Co3O4 microspheres with core–shell primary nanoparticles show excellent cycling and rate performances as anode materials for lithium‐ion batteries. |
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Keywords: | core– shell Kirkendall diffusion lithium‐ion battery spray drying yolk– shell |
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