Mo掺杂锰基层状氧化物构建稳定钾离子电池正极材料

Mo Doped in Manganese Basal Oxides to Construct Stable Cathode Materials of Potassium Ion Batteries

锰基层状氧化物具有比容量高、成本低等优点,是最有发展前途的钾离子电池正极材料之一。然而由于Mn^(3+)带来的Jahn-Teller效应,材料在循环过程中容易发生不可逆相变以及结构崩塌等现象,导致电池循环稳定性较差。为稳定层间结构,采用固相法通过Mo掺杂P3型K_(0.5)MnO_(2)制备了K_(0.5)Mn_(0.95)Mo_(0.05)O_(2),以此作为钾离子电池的正极材料,组装的半电池在20 mA/g的电流密度下具有73.69 mA·h/g的初始放电比容量,经过30圈循环后仍具有66.16 mA·h/g的放电比容量,保持率达90%。在100 mA/g电流密度下,首圈放电比容量为52.15 mA·h/g,循环100圈后仍有71%的容量保持率,具有良好的循环稳定性。

Manganese-based layered oxides have the advantages of high specific capacity and low cost,and are one of the most promising anode materials for potassium ion batteries.However,due to the Jahn-Teller effect resulting from Mn3+,the material is prone to irreversible phase transition as well as structural collapse during the cycling process,which leads to poor cycling stability of the battery.In order to stabilize the interlayer structure,K_(0.5)Mn_(0.95)Mo_(0.05)O_(2) was prepared as the cathode material in potassium-ion batteries by the solid-state method with Mo-doped P3-type K_(0.5)MnO_(2).The assembled half-cells had an initial discharge specific capacity of 73.69 mA·h/g at a current density of 20 mA/g,and a specific capacity of 66.16 mA·h/g after 30 cycles,it had a retention rate of 90%.At a current density of 100 mA/g,the initial discharge specific capacity was 52.15 mA·h/g,and the capacity retention rate was still 71%after 100 cycles,which had good cycle s tability.