Pyrite-based cathodes for lithium batteries: a systematic study about the effect of the active material?s concentration

E. PRIMO; M. V. BRACAMONTE; G. LENER; G. L. LUQUE; D. E. BARRACO; P. G. BERCOFF

Bologna

Congreso; 69th Annual ISE Meeting; 2018

Pyrite (FeS2)is a natural, abundant and non-toxic mineral which is a promising candidate forcathode materials in lithium batteries. Even though the pyrite?s theoretical capacityis 894 mAhg−1, FeS2 suffers poor cycling stability due to the volumefluctuations, formation of soluble lithium polysulfides and poor ionic/electricalconductivity of lithiation products. This conversion type cathode with several possiblereaction pathways during lithiation/delithiation has been poorly analyzed in termsof the effect of the amount of active material in the electrochemical mechanism.In this work,we report the synthesis of pyrite (FeS2) by high-energy mechanical ball millingof a powder mixture of Fe and S powders in a 1:2 ratio. The formation of the FeS2phase requires 72 h milling time. After that, a thermal treatment at 350 ºC in vacuumwas performed to promote the complete formation of pyrite. The electrochemical performanceof cathodes prepared with different percentages of the synthesized powder was evaluatedand the results are summarized here.