Pyrite based cathodes for lithium batteries. Studies of a biocarbon coating for the enhancement in their electrochemical performances

VICTORIA BRACAMONTE; EMILIANO PRIMO; COZZARÍN, MELINA V.; GUILLERMINA LUQUE; DANIEL BARRACO; EZEQUIEL P. LEIVA

Santiago

Workshop; IWLIME 2020; 2020

CELIMIN

Iron (II) sulfide, also known as pyrite, has been acknowledged as a promising cathode material due to its natural abundance, low cost, and nontoxicity . FeS2 comprises 53.3 wt% of sulfur and46.6 wt% of iron, organized in a cubic structure. Fe2+ cations in pyrite are in a low spin d6 configuration, making it a diamagnetic and semiconductor material . Regarding itsapplication in lithium batteries, Li/FeS2 primary battery has been recently launched by Energizer®, which outputs a better performance when compared to the alkaline ones . Thedischarge of FeS2involves four electrons and yields a theoretical specific capacity of 894 mAh g-1. However, its use in rechargeable LIB is limited by its poor stability and cycling due to thevolume fluctuations, formation of soluble lithium polysulfides and poor ionic/electrical conductivity of lithiation products . In this way, strategies not only to prevent polysulfides? diffusion, but also toincrease the conductivity of the material are required for the effective application of FeS2in batteries for commercial and industrial use. In this work, we present the synthesis and characterization of hybrid structures based on FeS2 and carbon (FeS2-C) for their subsequent application as active cathode materials for Li-S batteries.