Head coach Dean Smith beat off stiff competition from Derby County to land the 21-year-old on a dramatic deadline day for the west London club.
The Bees paid £1.5 million – a club record for a teenager – for the services of Walsall and England U19 left back Rico Henry on a five-year deal and tied down midfielder Ryan Woods to a new four-year contract.
Kaikai, who made his top-flight Palace debut in a 4-1 defeat at Southampton at the end of last season, scored a preseason brace for the Eagles at Bromley earlier this month, having finished last term as League One Shrewsbury Town’s leading scorer with 12 league goals.
He has watched his Selhurst Park paymasters recruit Belgium international Christian Benteke for £27 million this summer, but he is in no doubt the Bees can help him plot a route into boss Alan Pardew’s first team.
“I scored a few at Shrewsbury and played well and I’m just looking to replicate the same form at Brentford,” he said.
“From every loan I’ve been on I’ve improved. I want to do the same here, so I’m just looking to get some minutes under my belt and score as many goal as I can.
“I played in the Premier League at Palace last season and experienced the level I need to get to.
“It’s very exciting and I know that with this loan I will improve a lot and hopefully break into the Crystal Palace first team soon.”
Henry, 19, is unlikely to feature anytime soon as he is sidelined with a shoulder injury, but co-director of football Phil Giles is comfortable with the move.
“We are fully aware of the extent of the shoulder injury and have taken expert advice on it,” he said “The main priority is that Rico recovers well and is 100 per cent fit in the long term.”
“We are very comfortable with the fact that Rico may not play for Brentford in the foreseeable future as Tom Field and Callum Elder will continue to compete for the left back position.”
Brentford’s cash cffers were swelled following former centre back Alfie Mawson’s £5million move to Swansea City from Barnsley.
The 22-year-old turned down a new contract with the Bees last summer to leave Griffin Park last summer bound for the Tykes in a deal that had a sell-on clause written in.
In other good news, the London Borough of Hounslow completed the Compulsory Purchase Order land acquisition for the Brentford Community Stadium this week.
The council has taken freehold possession of the land - including the Lionel Road South, Duffy and Capital Court sites - and the Bees have taken control of this land through lease arrangements.
The freehold interest will return to the club on completion of the new stadium development.
Before any work can start on site, there are a number of planning and Section 106 requirements that have to be fulfilled.