Running your simulation (as supplied), if you look at the current draw on the power source (battery) at say 4.85ms, you get this:
![Effect of switching current on Li-ion battery packs 924068-0](https://www.eevblog.com/forum/index.php?action=dlattach;topic=229002.0;attach=924070;image)
You'll see that the current is being drawn by your converter in pulses. Any inductance in the supply to this (e.g. battery chemistry, construction, leads, etc..) will have an effect on this ability to draw current and likely affect your stability/function of your converter.
If I put in a small ESR for the battery (say 0.02ohms) and just look at the ripple current that C13 (which says 4.7uF x2 - but is actually set to 4.7uF not 9.6uF?):
![Effect of switching current on Li-ion battery packs 924072-1](https://www.eevblog.com/forum/index.php?action=dlattach;topic=229002.0;attach=924074;image)
Peak currents of around 3.6A in C13 - that needs to be a pretty special 4.7uF capacitor to take that ripple. I would increase it and model is with at least it's ESR included.
Here's what happens if you change:
C13 to C1210C106K3RAC 10uF from KEMET (Mouser stocked part)
L7 (wire), 100 mm of 4mm CSA wire (
https://www.eeweb.com/tools/wire-inductance)
![Effect of switching current on Li-ion battery packs 924076-2](https://www.eevblog.com/forum/index.php?action=dlattach;topic=229002.0;attach=924078;image)
You'll notice that the ripple current experienced by the battery is much lower. Perhaps adding a bit more inductance (a filter basically) will reduce this further (lower EMI, lower heating due to AC component in battery). I'd probably add a delibrate PI filter, or perhaps add a capacitor across the battery directly to create this filter with any wiring.
You'll have to do some calculations with C13 to see if it will take the ripple (clue: Dissipation Factor!)