Additive to ceramic ion conducting material to mitigate the resistive effect of surface carbonates and hydroxides

A method of modifying a carbonate layer formed on a surface of an electrochemical cell component, the surface comprising a ceramic oxide and the carbonate layer comprising lithium carbonate (Li2CO3), sodium carbonate (Na2CO3), or a combination thereof and being substantially non-conductive to lithium ions, sodium ions, or a combination thereof, the method comprising:

• contacting the carbonate layer of with a modifying agent comprising MX, where M is Na or Li and X is a halide, to form a mixture;
• pressing the mixture in a die defining a predetermined shape;
• and
• during the pressing, heating the mixture at a temperature greater than or equal to about 300° C. to incorporate the MX into the carbonate layer and to form a modified hybrid layer comprising a eutectic mixture of the MX and the Li2CO3, Na2CO3, or combination thereof, the modified hybrid layer being conductive to lithium ions, sodium ions, or a combination thereof.

A method of modifying a carbonate layer formed on a surface of an electrochemical cell component, the surface comprising a ceramic oxide and the carbonate layer comprising lithium carbonate (Li2CO3), sodium carbonate (Na2CO3), or a combination thereof and being substantially non-conductive to ions, the method comprising:

• contacting the carbonate layer of with a modifying agent comprising LiF, NaF, or a combination thereof to form a mixture;
• and
• causing the modifying agent to incorporate into the carbonate layer and to form a modified hybrid layer comprising a eutectic mixture of the LiF, NaF, or the combination thereof and the carbonate, the modified hybrid layer having an ionic conductivity of greater than or equal to about 0.1 mS,
• wherein the ceramic oxide is optionally doped and comprises Li7La3Zr2O12 (LLZO), LixLayTiO3 where 0<x<1 and 0<y<1 (LLTO), Li1+xAlyTi2−yPO4 where 0<x<1 and 0<y<2 (LATP), Li2+2xZn1−xGeO4 where 0<x<1 (LISICON), Li2PO2N (LIPON), sodium equivalents thereof, or combinations thereof, and
• wherein the electrochemical cell component is a solid-state electrolyte, a separator, or a coating disposed on a separator.