Lithium polyacrylate-coated LiMn₂O₄ cathode materials with excellent performance for lithium ion batteries

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• 作者：Qingtang Zhang ; Xiaolong Xie ; Weifeng Fan ; Xiaomei Wang
• 关键词：Lithium manganese oxide ; Electrochemical performance ; Lithium polyacrylate ; Lithium ion battery ; Rate capability
• 刊名：Ionics
• 出版年：2016
• 出版时间：December 2016
• 年：2016
• 卷：22
• 期：12
• 页码：2273-2280
• 全文大小：
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Electrochemistry; Renewable and Green Energy; Optical and Electronic Materials; Condensed Matter Physics; Energy Storage;
• 出版者：Springer Berlin Heidelberg
• ISSN：1862-0760
• 卷排序：22

文摘

A novel facile approach to coat LiMn₂O₄ by lithium polyacrylate (PAALi) is demonstrated. The PAALi-coated LiMn₂O₄ (LMO@2%PAALi) and LiMn₂O₄ (LMO) are characterized by charge–discharge tests, X-ray diffraction (XRD), PAALi dissolving experiment, transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), thermogravimetry (TG), and inductively coupled plasma optical emission spectrometer (ICP-OES). XRD and FTIR analyses indicate that there are no clear differences between LMO@2%PAALi and LMO. PAALi dissolving experiment indicates that PAALi is indissolvable in LiPF₆-EC/DMC/EMC electrolyte. TEM results reveal that LiMn₂O₄ particles are coated by PAALi. ICP-OES results indicate that this stable PAALi coating can prevent the Mn ions dissolving from active LiMn₂O₄ materials and then the stability of LiMn₂O₄ crystals in electrolyte are greatly enhanced. These unique features ensure that LMO@2%PAALi possesses much better rate performance, higher discharge capacity, better cycling performance, and lower charge transfer resistance over LMO. The discharge capacity of LMO@2%PAALi at 0.2 C reaches up to 127.2 mAh g−1 at room temperature.