Lifepo4 current limiter with supercapacitor in parallell
Theoretically, an RLC circuit should work:







simulate this circuit &ndash; Schematic created using CircuitLab

L1 is supposed to limit the current during the spike, while providing a lossless current transfer on DC, and making use of energy stored in the B field to charge the capacitor after the spike is over. R1 may be needed to keep overshoots limited. You may still want to include some sort of fuse to protect the battery in case your current spike is longer than you have expected.

However, my feeling is that for your parameters you will end up with a prohibitively large L value for the inductor.