[peteey]

Yes and no. Lithium metal is the highly reactive element in batteries.

Similar to Hydrogen and Sodium, elements in the first column of the periodic table are highly reactive (flammable) because they readily give away their single electron in the outermost orbital.

Some Lithium battery variants might have marginally safer properties, but they are fundamentally volatile at full charge.

[philipkglass]

Commercial lithium ion batteries do not contain metallic lithium in the charged or uncharged state. They have lithium ions intercalated into the anode material in the charged state.

Primary (disposable) lithium batteries do contain metallic lithium in the charged state, and there are efforts to develop rechargeable batteries using pure lithium metal at the anode. Rechargeable batteries that contain metallic lithium anodes would be able to store more energy, but they are also more hazardous and currently have low cycle life.

[girvo]

Most batteries have lithium complexes (cobalt oxide, iron phosphate, and so on) though, not elemental Li, and so have different properties.