Are Lithium Thionyl Chloride Battery usable in my vibrating environment? Are they safe?
Firstly - you will experience more parasitic discharge or self discharge of the batteries that you expect.
Secondly - The batteries themselves are a chemical reaction,and additional kinetic energy will induce some frictional heat in the battery itself. This induced heat will need to be shed to prevent it affecting the battery environment and creating accelerated aging, or worse still an accelerative heating loop (increase in temp = increase in electrical output = increase in temp) called thermal runaway.
Thirdly - the battery construction will be an issue.  These batteries typically use stacked coin cell type construction with a manganese dioxide cathode and metal grid collector. Movement of the cathod agaisnt the grid will cause cathode degredation and harm performance. Whether this can actually occur becuase of the vibration - I don't know.