Save battery on SNES Super Mario World cartridge?

I've managed to get a SNES with Super Mario World from a friend of mine, but the game won't save my progress. I Googled around a bit and figured out that SNES games use a battery to save their files, and since the cartridge was old, I'd need to replace it.

So far so good, but when I opened the cartridge, I couldn't find an old battery or even space for one. Is this one different? Is it even official? How do I fix my problem?

Simply put, this is a counterfeit cartridge. That black spot contains a tiny chip under it which contains the ROM data.

This was likely created (guesstimate) well after the lifecycle of the SNES. Also, I don't have a SNES cartridge near me at the moment but I think that case is not a legit donor case either.

You didn't post images of the other side, but if we can see the label we could definitely confirm if it's 100% fake.

Where and when did your friend get this? This would have never saved data.