| 离子交换法制备层状LixNi0.3Mn0.7O2正极材料及其离子交换规律的研究 |
| Studies on the Influence of Ion-exchange Conditions of LixNi0.3Mn0.7O2 for Rechargeable Lithium Batteries: Structure, Composition and Properties |
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| 摘要: 通过共沉淀法高温固相反应在空气气氛中合成出具有P2型结构特征的碱青铜前驱体Na0.66Ni0.3Mn0.7O2，研究了在4种不同离子交换条件下进行离子交换反应得到目标正极材料LixNi0.3Mn0.7O2的离子交换规律，并用XRD、SEM、粒度分析和电性能测试考察了目标正极材料及其前驱体的结构、形貌和电化学性能。结果表明，以熔融LiNO3为介质于300 ℃离子交换4h反应进行得最为完全，离子交换率达98 %，且目标正极材料具有较完善的O2型层状结构，在2.6～2.9 V存在唯一的充放电平台，循环过程中未发现向尖晶石相转变；而离子交换时间过长，目标正极材料将出现尖晶石相而影响其放电容量和循环稳定性。 |
| 关键词: 正极材料 离子交换 层状 LixNi0.3Mn0.7O2 |
| 基金项目: |
| Abstract: Layered sodium manganese bronze Na0.66Ni0.3Mn0.7O2 with a P2-structure as the precursor has been synthesized in atmosphere by coprecipitation method. The influence on the structure and electrochemical properties of the aimed materials LixNi0.3Mn0.7O2 caused by ion exchange of Na+ by Li+ at four different ion-exchange conditions have been investigated. XRD analysis, SEM and electrochemical tests were used to study the physical and electrochemical performances of the precursor and the products. The sample exchanged by molted salt LiNO3 for 4 h shows the best electrochemical properties, which has an O2 structure and only one charge-discharge potential stage of 2.8 V when cycled between 2.5～4.2 V. Its initial discharge capacity is 168 mAh·g-1 and the 40th discharge capacity remains 156 mAh·g-1. But when the ion-exchange time become longer in molted salt LiNO3, the sample would turn to spinel phase LixMn2O4. |
| Keywords: lithium-ion battery cathode material ion exchange LixNi0.3Mn0.7O2 |
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| 钟 辉,许 惠,周燕芳.离子交换法制备层状LixNi0.3Mn0.7O2正极材料及其离子交换规律的研究[J].无机化学学报,2004,20(3):261-266. |
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