Despite the lack of goals, the showpiece at Wembley Stadium was not lacking entertainment, and that continued in a shootout after the two teams could not be separated, just like in February's EFL Cup final.
Cesar Azpilicueta's miss handed Sadio Mane the chance to win it for Liverpool, only for the forward to see his effort saved by Senegalese compatriot Edouard Mendy, but Kostas Tsimikas would become the Liverpool hero after Alisson Becker had previously kept out Mason Mount's shot down to his left.
In claiming another final victory over Chelsea, Liverpool remain on course for the quadruple, although they require a favour from West Ham United when the Hammers face Manchester City on Sunday.
While Liverpool had the better of the opening stages and went close through Luis Diaz, who had a shot blocked by the legs of Mendy, Chelsea created chances of their own with Christian Pulisic hooking a shot from eight yards wide of the post.
After Jota diverted the ball over from close range and Romelu Lukaku sent a wild shot over the crossbar at the other end, the two teams went into half time still goalless.
That almost changed soon after the restart, Marcos Alonso sending a volley marginally wide of the far post and seeing a free kick from an acute angle hit the underside of the crossbar and bounce to safety.
Pulisic also saw a shot parried away by Alisson, while Liverpool pair Diaz and Jota both sent low efforts of their own agonisingly past Mendy's far post.
As the game approached the final stages, chances began to dry up, but Diaz and Andrew Robertson both hit the woodwork in the space of two minutes, Diaz the near post from 12 yards and Robertson at the back post after meeting a James Milner cross.
Liverpool remained in the ascendancy as extra time grew ever nearer, with the final chance of normal time falling to Diaz who sent an inswinging curler inches wide of the far post.
Before the additional 30 minutes commenced, Virgil van Dijk was withdrawn, but Joel Matip stepped into the breach to help his side have the better of extra time, even if there was an inevitability about a final between these two clubs being decided from 12 yards yet again.
That preserved matters as Mane squandered a chance to put his name in lights, and it was left to Alisson to save Mount's poor attempt to give Tsimikas the opportunity to send the perfect low penalty to Mendy's right as the goalkeeper dived the opposite way. body check tags ::