You should remove the battery from the aircraft, terminals taped over and in a lipo bag.
I flew to the US last year through Manchester Airport, aftre fiollowing thesae guidelines, the only thing they warned me about was not to try and fly it onboard the plane!
From
https://www.caa.co.uk/Passengers/Before-you-fly/Baggage/Items-that-are-allowed-in-baggage/ :
Spare batteries for portable electronic devices containing lithium ion batteries exceeding a Watt-hour rating of 100 Wh but not exceeding 160 Wh when carried for personal use.
No more than two individually protected spare batteries per person may be carried.
Each lithium ion cell or battery must be individually protected so as to prevent short circuits (by placement in original retail packaging or by otherwise insulating terminals, e.g. by taping over exposed terminals or placing each battery in a separate plastic bag or protective pouch).