A MC/AQ Parasitic Composite as Cathode Material for Lithium Battery

Abstract

The mesoporous carbon (MC)/9,10-anthraquinone(AQ) parasitic composite is prepared by thermally treating a mixture of AQ and MC. As AQ ratio is 68%(w/w) in the composite, scanning electron microscopy (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), mercury porosimeter, and Brunauer-Emmett-Teller (BET) characterization show that AQ is parasitized inside nano-pores of MC in the composite. Tested as the cathode material in a lithium cell at room temperature, compared to AQ electrode, the composite electrode shows better electrochemical performance. It exhibits a specific capacity up to 222 mAh.g−1 at the initial discharge and its specific capacity remains 97 mAh.g−1 after 50 cycles. Meanwhile, the parasitic composite also exhibits a high-rate behavior at a current density of 600 mA.g−1. Electrochemical impedance spectroscopy (EIS) is introduced to understand the impact of the microstructure of composite on electrochemistry. Furthermore, morphology analysis of AQ and composite electrodes in different discharge stages confirms that the adsorption of MC makes the electrochemical reaction restrict within the areas of pores, which can maintain the stable structure during the charge and discharge process.