A novel conversion of converter sludge into amorphous multi-doped FePO4 cathode material for lithium ion batteries

A multi-doped FePO4 was synthesized using converter sludge as raw material for lithium ion battery cathodes. The processes included sulfolysis of the sludge to leach target ions into the filtrate, reacting the filtrate with phosphoric acid to prepare a precursor, and roasting the precursor to obtain the single-phase multi-doped FePO4. The results indicated that the obtained product delivers an enhanced capacity of 130 mA h g−1 at 0.1 C owing to the doping effect of the multiple metal ions derived from the converter sludge.