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.