磷掺杂葵花盘基活性炭在锂离子电池负极材料中的应用

Application of phosphorus-doped sunflower disk-based activated carbon in anode materials of lithium ion batteries

通过简单水热和活化方法制备磷掺杂葵花盘基活性炭,采用SEM,TEM,BET,Raman,XRD等方法对材料进行表征,将其用作锂离子电池负极材料。结果表明,活性炭材料用作锂离子电池负极材料时比容量高,库伦效率好,循环性能稳定。在500 mA/g的电流密度下,首圈充电容量达1 052 mAh/g,库伦效率为48.9%。经200次循环后,容量仍保持在1 000 mAh/g以上。

Lithium ion batteries(LIBs)have progressively attracted researchers in recent years because of their environmental friendliness and adequate resources.In order to take full advantages of the active carbon in nature,the cheapest and most efficient negative electrode material for lithium ion battery is in great need.Because sunflower was fully-infected compositae,the sunflower disk had a more stable nanostructure than other biochars.Moreover,the sunflower dish is not only rich in nitrogen and oxygen element,but also widely distributed in the world.In this work,P-doped activation carbon composites were prepared to achieve excellent electrochemical performance in rechargeable LIBs.Phosphorus-injected biomass activated carbon was prepared with simple hydrothermal and calcine methods.The characteristics of activated carbon were then tested with field emission scanning electron microscope(FE-SEM),transmission electron microscope(TEM),X-ray diffractometer(XRD),Raman spectrometer,Brunauer Emmett Teller(BET),etc.When these products were applied in lithium ion battery anode materials,the electrodes achieved high energy density and Coulombic efficiency,and cycling stability simultaneously.When the battery cycling at the current density of 500 mA/g,the elementary charge capacity reached to 1 052 mAh/g,with the Coulombic efficiency of 48.9%.After 200 cycles,the capacity still maintained 1 000 mA h/g or more.However,activated carbon capacity of the contrast sample without phosphoric acid activation can only be maintained at 300 mA h/g,which was similar to ordinary carbon materials.Hence,the preparation method of the P-doped biomass resulting in activated carbon was simpleness,and the raw material was low cost and environmentally friendly.Most importantly,the electrode potential of the material was low,and the discharge platform remained stable,which was of great research value in the lithium ion battery in a commercial application.