The ornamental design for a lithium electric grinding, as shown and described.
FIG. 1 is a front elevational view of the lithium electric grinding showing my new design;
FIG. 2 is a rear elevational view thereof;
FIG. 3 is a left side elevational view thereof;
FIG. 4 is a right side elevational view thereof;
FIG. 5 is a top plan view thereof;
FIG. 6 is a bottom plan view thereof; and,
FIG. 7 is a front,right side perspective view thereof.
The broken lines in the drawings are for the purpose of illustrating portions of the lithium electric grinding that form no part of the claimed design.