Li-S batteries: improving polysulfide retention by cathode coating with a nanostructured carbon

GARCIA-SORIANO, F.; LENER, G.; GUILLERMINA LUQUE; BARRACO, D.E.; LEIVA E. P. M.

Congreso; 1st Annual Meeting of ISE; 2020

Li-S batteries represent a potential solution to obtain high-performance electrochemical energy storage devices. This is sobecause of their high theoretical specific capacity 1672 mAh g -1 andhigh energy density 2600 Wh kg -1 . [1] An important diffuculty to besolved before a practical application is the formation of long-chainpolysulfides (Li 2 S n , n≥4) during sulfur lithiation. Polysulfides aresoluble in the commonly used ether-based electrolytes and thereforecan migrate to the anode where they undergo further reduction(shuttle effect), which ultimately leads to the passivation of thelithium anode. [2] In this work we use a combination of carbonstructures on the cathodic side of the cell to achieve electronic andionic conductivity, and, at the same time, the mitigation of theshuttle effect. In order to retain the polysulfides in the cathode andprevent their migration to the anode carbon nanofibers (CNF),obtained from natural raw clay, was used to directly coat the sulfurcathode.