powertool or angle grinder to borrow to cut bike D-lock (Brunswick BN3)

Hi I need to use my bike but the kryptonite D-lock has somehow gotten stuck from being outside. Ive tried all the online tips like using WD-40 plus lots can oil. Ive tried a hammer. Now the key holder part has broken off Ive been trying to turn it so hard so its just the stem left. I have to use pliers to try turn it but it only turns so far. So it seems Ill need to cut the lock free. I dont have any powertools so was wondering if anybody has one to loan. I dont want to keep it. Its locked outside my house so I guess a heavy duty cordless angle grinder would be ideal. The lock is a kryptonite d-lock so tough steel like over 1cm thick.