I want to make a wearable project for babies, is the commercial batteries safe for babies? Lithium Battery or Alkaline AA Battery? or can be risk to use them? the current provide by the batteries can harm the baby?
You can, just be careful with the design. Make sure all the connections are adequately insulated and robust enough to handle the loads. Use an enclosure that requires tools to open, nothing that could be opened by hand alone. Leave overhead so you're not drawing the battery close to it's operating limits. This will help insure it doesn't overheat.