Breaking Lithium Salts In The Solid Electrolyte Interphase In Batteries

 The experimental Li-F bond length in lithium fluoride ($LiF$) is $1.564\,A$;

$f_{res}=0.122\cfrac{c}{BL}$

$f_{res}=0.122*\cfrac{299792458}{1.564}*10^{10}$

$\cfrac{f_{res}}{10^{15}}= 233.853\,\,Hz$

Breaking Li-F bond in Lithium Fluoride 233-853 Hz

The experimental Li-O bond length in Di-Lithium Oxide ($Li_2O$) is $1.606\,A$;

$f_{res}=0.122\cfrac{c}{BL}$

$f_{res}=0.122*\cfrac{299792458}{1.606}*10^{10}$

$\cfrac{f_{res}}{10^{15}}=227.738\,\,Hz$

Breaking Li-O bond in Di-Lithium Oxide 227-738 Hz

As for Lithium Carbonate, which bond to break to dis-associate the salt?  One bond length value stands out as shortest of three C-O bonds in the crystalline structure of $Li_2CO_3$ (Data from   https://www.osti.gov/dataexplorer/biblio/dataset/1204937).

The one short C-O bond length in $Li_2CO_3$ crystals is $1.26\,A$

$f_{res}=0.122\cfrac{c}{BL}$

$f_{res}=0.122*\cfrac{299792458}{1.26}*10^{10}$

$\cfrac{f_{res}}{10^{15}}=290.275\,\,Hz$

Breaking short C-O bond in Li2CO3 crystals 290-275 Hz

This frequency might free the carbon in the crystal lattice as $CO_2$,resulting in free $O$ radicals and atomic lithium.  Breaking the other two C-O bonds at $1.31\,A$, might produce $CO$, carbon monoxide.

The free radicals produced as the result of these sonic decompositions will result in new compounds being formed in the SEI.  For worse or for better...

Have a nice day.