Methods for making a solid electrolyte interface layer on a surface of an electrode

A method for making a solid electrolyte interface (SEI) layer on a surface of an electrode, the method comprising:

• exposing the electrode to an electrolyte solution in an electrochemical cell, the electrolyte solution including either i) an organo-polysulfide additive having a formula RSnR′ (n≥2), wherein R and R′ are independently selected from a methyl group, an unsaturated chain, a 3-(Trimethoxysilyl)-1-propyl group, or a 4-nitrophenyl group or ii) a fluorinated organo-polysulfide additive having a formula RSnR′ (n≥2), wherein R and R′ can be the same or different, and wherein R and R′ each have a general formula of CxHyF(2x−y+1), where x is at least 1 and y ranges from 0 to 2x;
• and
• applying a voltage or a load to the electrochemical cell, wherein the applying of the voltage or the load causes the organo-polysulfide additive or the fluorinated organo-polysulfide additive to react to form the SEI layer.