Effect of Side-Plane Width on Lithium-Ion Transportation in Additive-Free LiCoO2 Crystal Layer-Based Cathodes for Rechargeable Lithium-Ion Batteries

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• 作者：Dae-wook Kim ; Nobuyuki Zettsu ; Yusuke Mizuno ; Katsuya Teshima
• 刊名：Journal of Physical Chemistry C
• 出版年：2016
• 出版时间：August 25, 2016
• 年：2016
• 卷：120
• 期：33
• 页码：18496-18502
• 全文大小：499K
• 年卷期：0
• ISSN：1932-7455

文摘

Rechargeable lithium-ion batteries (LIBs) with improved performance, including higher power, higher energy density, and superior cycling performance, are in demand for highly specialized applications. The design and synthesis of cathode materials with effective shapes surrounded by suitable faces for Li-ion transportation are essential for high-performance LIBs. In the present work, we address the effects of side-plane width on the Li-ion diffusion coefficient and charge transfer resistance of additive-free LiCoO₂ electrodes composed of highly controlled crystals with exposed {101}, {012}, and {104} faces. The changes in the shape and order of orientation in the LiCoO₂ crystals were evaluated using electron microscopic observations and X-ray diffraction measurements. The discharge capacity drastically increased from 87.9 to 131.5 mA·h·g^–1 on increasing the width of the side plane in the LiCoO₂ crystal from ca. 11 to ca. 59 nm. Further, electrochemical impedance spectroscopy revealed that the Li-ion diffusion coefficient and charge transfer resistance of the electrodes were related to the dimensions of the exposed {101}, {012}, and {104} faces. Thus, increasing the crystal faces available for Li-ion transfer provides layer-based cathode materials with increased discharge capacities.