Copper that thick is not cheap. The biggest I used was gauge SWG28. Well you might do it for fun if you have nothing better to do. For me, I think a MCU project to control something is more interesting.
Just go ahead and follow the instructions in the INSTRUCTIBLES. I think it should work but dont expect too much from it. You need 10 times of time to fully charge up your handphone and I see no regulator on the slave side. An led would need about 10mA to light up, so I think the current wouldnt be very much.
Do share it here if your project works successfully and dont forget to take a few photos and paste it here.
Allen