You can always set up a forward base close to the Purple Vents biome to make collecting Lithium a bit easier. Eventually, you will need a lot to complete all your building projects, even if you're not going for a megabase. This is why it's a good idea to start stockpiling Lithium. Not only will you need it to build the Large Room, but it's also used to build things like the Power Cell Charger and the Dome Roof for the Multipurpose Room. Lithium is also a crucial crafting material for loads of different building modules.