Mercury Cells are one of the cell types in GregTech.
One of the uses of mercury cells is using them instead of water in an Industrial Grinder. Depending on a recipe, this helps to produce either 3 piles of a main product instead of two or a full pile of side product instead of one or two tiny piles. It also helps to produce more gold nuggets when grinding Netherrack.
Mercury cells can also be used to craft Single-Use Batteries.
Mercury cells can also be used in Magic Energy Converter for 8000 EU per cell.
Quicksilver + empty cell in an AUTOMATIC (only) canning machine will produce 1 mercury cell. This will not work with a Standard Canning machine when Gregtech is installed.