Electrical tape might be a little messy, it also could slip off the connection and eventually cause a short. It depends on your goal, Is this a short term or long term connection?
If it is short term, have fun with your electrical tape.
If it is long term, get yourself some heat shrink tubing to fit over the connections. It is basically thin rubber tubes that fit over wires/connections, and when you blast it with a hair dryer it shrinks around the connection securely.
BTW, if you get the shrink tubing, remember to slide the tubing onto one of the wires
before you solder them together, so that you can slide the tube over the connection
Edit: Please don't post in 2 different forums next time...