>>64101965
>the current LIB has an energy density of about 150 Wh/kg
Which is over 3x that of LA (~40 Wh/kg). Also, volumetric efficiency (Wh/L, a.k.a. Wh/cubic decimeter) is around 5x, at 390 versus 75 (which is important, because physical space in a sub is extremely limited). All around, you can fit 3x the amount of LIBs per weight compared to LA, or 5x the amount per size.
>going at 15 knots alone would require at least 3 Mw, so that not even 2 days.
The difference is you *can* go 15 kt on LIBs (heck, you can go flank, if you don't mind having to surface after 3 hours, and spending the next 2 with your dick out recharging), whereas on FC you're stuck puttering along at 7-8 kt max. And then you still have to snorkel for a big charge, since FCs produce relatively low power. Like I said, with batteries, you can go fast if you need to, or you can go slow to preserve charge.
>why didn't Worst Korea go for all-LIB in the KSS-III Batch 2, then
Because a) they don't need them, their main enemy is right next door, so puttering along at 8 kt is acceptable due to short distances. And b) all-LIB layout is very expensive, and Worst Koreans have relatively tight military budgets, needing to spread the money on a lot of different systems, air, sea, and land. Hence why Batch 2 recycles most of the Batch 1 design (for cost reasons) while adding a few evolutionary improvements (like LIBs instead of Batch 1 LAs, which weren't a thing back in the early-mid-2010s when the original Batch 1 design was finalized).
