Properties of graphitized boron-doped coal-based coke powders as anode for lithium-ion batteries

• The electrochemical performance of coke powder for Li-ion batteries was studied.
• The effects of boron content and graphitization temperature were investigated.
• Proper content of boron can improve the electrochemical properties of coke powder.
• Higher graphitization temperature helps to improve the electrochemical properties.
• A mechanism on how and why doping increases the capacity was proposed.

Coal-based coke powder is a by-product when coke is smashed for metallurgy and chemical industry. There is a vast output of coke powder every year around world, most of which is combusted as cheap fuel or abandoned directly. In this work, the electrochemical performance of graphitized boron-doped coal-based coke powder as anode for lithium ion batteries was investigated. The effects of boron content and graphitization temperature on the anode performance of boron-doped coal-based coke powder were also investigated in this paper. Results showed that a reversible capacity of 360.3 mA h/g of boron-doped coal-based coke powder can be obtained, while that of unboron-doped was 292.9 mA h/g. X-ray diffraction (XRD) analysis for the boron-doped coal-based coke powder showed that the distance between carbon layers was lowered by a proper amount of doped boron and higher graphitization temperature. X-ray photoelectron spectrometer (XPS) analysis was carried out to explain the effect of boron doping on the electrochemical performances of coal-based coke anodes.