Air carrier Captain reported a passenger deplaned at destination with two large Lithium Ion batteries which were not configured for cabin transport. The Captain was not notified about batteries in cabin prior to departure.

Narrative

After block in and during deplaning the aircraft; a passenger was walking out with two large motor vehicle-sized batteries in hand. Both batteries stated Lithium Ion" on their original labeling. I did not notice any tape on the terminals and they were not sealed in any way in a bag or alternate method per company procedures. All 4 flight attendants were equally surprised by this and the departure station Gate Agent never advised us of the batteries or any hazmat in her pre-departure brief as required by our company procedures.Inbound aircraft arrived later than scheduled with an already minimal scheduled turn around time between flights. There is a lot of perceived and imposed pressure placed upon gate agents; ramp personnel; cabin crew; etc. directly from the company in order to achieve door closing no later than departure time minus 10 minutes. This results in hasty operations and can lead to cutting corners or mistakenly and willfully omitting necessary procedures in the interest of an on-time departure. Retraining station personnel and flight attendants to recognize and ensure such hazmat is not boarded."