The battery configuration seems to be 4S2P, with custom 18650 Li-Ion cells.

Two circuit boards are on the USB plug end, with large inductors inbetween, that are stuck in place with white silicon(?) glue.

The heat conducting grey foam has some sort of black heat spreader under it, with the thermocouple attached to that - the heat spreader seems to go below the (heat isolating?) white sticky foam that is over the battery part.

I didn't risk disassembling my power bank any further as I still need it - there seem to be phillips screws holding down the circuit board though.

The circuit board has the battery balancing circuitry directly on it, there isn't a seperate battery protection board.

The case seems to provide reasonable physical protection of the cells from sharb objects with double walls.

I didn't research any of the chips, they don't have the marking removed though.