The diagram shows the overcharge of the TSWB cell and the temperature increase.
The cell is overcharged (after already being fully charged) gradually to 5V, 6V and 8V per cell. The temperature is monitored. The temperature reaches some 130*C.
The total time of the test is 30 minutes. During the test the cell did not explode, did not start burning, did not set itself on fire.
The TSWB cells are the most safe and reliable LFP cells with 10-year history of 10000+ customers.