Unfortunately, Lithium batteries can spontaneously combust, even primary Lithium batteries.

For emergency flashlights Alkaline batteries will yield a much longer run-time than Lithium *if* you can find an unregulated / direct-drive flashlight. It'll get pretty dim, but dim is better than black on a dark trail...

Battery manufacturers are allergic to datasheets or seemingly specs of any kind, but as I recall Alkaline and Lithium primary AA cells have about the same Ah rating, and that alkaline cells already have a shelf life over five years. But if Duralock improves the can against leakage that alone is good news.