P2型Na_0.71Co_0.8Mn_0.2O₂用于离子交换钾离子电池正极材料

P2 Na_0.71Co_0.8Mn_0.2O₂ for Ion Exchange Potassium Ion Battery Cathode Material

摘要: 通过固相法调控Na_0.71Co_1−yMn_yO₂ (y = 0, 0.2)中Mn掺杂含量，来制备层状氧化物正极材料并用于高性能钾离子电池电化学离子交换。应用X射线衍射(XRD)，扫描电子显微镜(SEM)对材料进行表征，了解材料的形貌结构，并对材料进行电化学性能测试。结果表明：P2型无序化Na_0.71Co_0.8Mn_0.2O₂ (y = 0.2)电化学性能明显优于有序化Na_0.71CoO₂ (y = 0)。所制备P2型无序化Na_0.71Co_0.8Mn_0.2O₂ (y = 0.2)半电池在50 mA·g⁻¹电流密度时有87.2 mAh·g⁻¹的首圈放电比容量，而在100 mA·g⁻¹电流密度下的长循环中，500圈后可以保持高达101.15%的容量，具有高的放电比容量和优异的循环性能。和Na_0.71CoO₂ (y = 0)相比，Na_0.71Co_0.8Mn_0.2O₂ (y = 0.2)电化学性能的优异是由于空位无序化结构保证了材料中K⁺的快速传输。

Abstract: The Mn doping content in Na_0.71Co_1−yMn_yO₂ (y = 0, 0.2) is regulated by the solid phase method to prepare layered oxide cathode materials and use them for electrochemical ion exchange in high-performance potassium ion batteries. X-ray diffraction (XRD) and scanning electron microscope (SEM) are used to characterize the material and understand the morphological structure of the material, and were tested for the electrochemical properties of the material. The results show that the electrochemical performance of P2 unordered Na_0.71Co_0.8Mn_0.2O₂ (y = 0.2) is significantly better than that of ordered Na_0.71CoO₂ (y = 0). The prepared P2 unordered Na_0.71Co_0.8Mn_0.2O₂ (y = 0.2) semi-battery has a first-ring discharge ratio capacity of 87.2 mAh·g⁻¹ at a current density of 50 mA·g⁻¹, while in long cycles under 100 mA·g⁻¹ current density, 500 cycles can maintain a capacity of up to 101.15% after 500 cycles, with high discharge ratio capacity and excellent circulation performance. Compared with Na_0.71CoO₂ (y = 0), the excellent electrochemical performance of Na_0.71Co_0.8Mn_0.2O₂ (y = 0.2) is due to the vacancy-disordered structure ensuring the rapid transmission of K⁺ in the material.