I have a multi-volt (7.2v - 20v) charger DW9116 that sparked when a battery was plugged in. I opened it up and found D23 was burnt. I've looked through a number of other postings online and some say it is a schottky diode while others say a normal diode, but the most common response I've found is that it is a "Transient Voltage Suppressor Diode)

I've found part numbers:
P6KE51A (manufacturer - littlefuse $.53)-Mouser link w/ Data sheet on the page

P6KE51A (Fairchild/ ON Semiconductor - $.47) Mouser page w/ Data sheet on page
This one doesn't list peak pulse current (above one is 8.3A) & listed as 6Kw power dissipation vs 600w above item! the breakdown V listed as 48.5 V to 53.6 V vs just 53.6v on the one above.

I also found this from a place I'm ordering from, it is similar, IDK if they can be used in series or paralled
https://www.allelectronics.com/item/p6ke33a/transient-voltage-surpressor-p6ke33a/1.html


Is there any other diode type that can be used? I saw some people recommend using something like paralleling IN4007, IN4003,

IDK if it makes much of a difference between the two and I also found them from China, 10-30 for about the same price after shipping at Mouser or Digikey. Do you think these are safe to order from china? I come across a lot of broken chargers which I would bet have a similar burnt diode, so maybe getting some extra's would pay off.

This was another part that was suggested.
P6KE6V8(C)A - P6KE440(C)A

 

It's basically a zener diode at 51V, it just clamps the supply from going over 51V to protect the battery.