解答:(Ⅰ)解:如图,设正方体的棱长为1,建立空间直角坐标系D-xyz,
则A(1,0,0),E(1,1,
),F(0,1 2
,0),D1(0,0,1),1 2
∴
=(0,1,AE
),1 2
=(0,
D1F
,?1),1 2
∵
?AE
=0,∴
D1F
⊥AE
,
D1F
∴异面直线AE与D1F所成的角为90°.
(Ⅱ)证明:∵
=DA
=(1,0,0),
D1A1
∴
?
D1A1
=0,AE
∴AE⊥D1A1,由(Ⅰ)知AE⊥D1F,且D1F∩D1A1=D1,
∴AE⊥平面A1D1F.