CuFeS2 as an anode material with an enhanced electrochemical performance for lithium-ion batteries fabricated from natural ore chalcopyrite.

Considering serious pollution from the traditional chemical synthesis process, the resource-rich, clean electrode materials are greatly desired. Conventional electrochemical performance improvement methods, such as quantum dot or coating, are complicated and costly. In this study, CuFeS₂ with an enhanced cycle performance is prepared from natural ore chalcopyrite through simple flotation and acid leaching. We obtain micro-sized CuFeS₂ with high yield and purity. Electrochemical measurement shows that the natural chalcopyrite with an EDD-S electrolyte displays a high initial charge capacity (992 mAh·g⁻¹ at the initial discharge current density of 0.2 C), an excellent rate performance, and good cycle property. The discharge capacities are approximately 870, 850, 830, 800, 750, and 680 mAh·g⁻¹ at current densities of 0.1, 0.2, 0.3, 0.5, 1, and 2 C, respectively. When the current density is reduced back to 0.1 C, the reversible capacity can recover to 860 mAh·g⁻¹, the cyclability is impressive (initial capacity of 700 mAh·g⁻¹ and 660 mAh·g⁻¹ maintained for 1000 cycles at a high current density of 2 C, corresponding to an excellent capacity retention of 94% after 1000 cycles). [ABSTRACT FROM AUTHOR]