Mine tailings as active electrode materials for Li-ion batteries

Mine tailings have been identified as a promising new source of battery anode material to cope with ever-increasing demands on battery supply chains. Two types of raw mine tailings are directly studied as anodes: pyrite-rich tailings with an initial specific discharge capacity of 570 mAh/g and an initial energy density of 104 Wh/kg when paired with an NMC111 cathode in a Li-ion full cell and a silicate-rich tailing with corresponding values of 288 mAh/g and 66 Wh/kg, respectively. However, tailings are a complex mixed mineral phase system; hence, their mechanistic behavior must be understood. The pyrite-rich tailing is shown to have a pseudocapacitance of 67.1% and impedance values >1,750 Ω during cycling, while the silicate-rich tailing has a pseudocapacitance of 87.2% and impedance values of <200 Ω during cycling. The results reveal the importance of mineralogy to electrochemical performance, furthering the potential of mine tailings with future enhancement strategies.