I wouldn't write such an email...

Only your first sentence is ok...

1. you need to fully understand what the team lead's role and responsibilities are.

2. outline clearly your skills and experiences that match the responsibilities.

3 list additional strength you have that will make you a good (or better/best) team lead.

After the email, you should have a face to face meeting withe the big boss.

Just my two cents. Good luck!