Hi,

IMHO, I think there is no direct clean way to prevent the browser to autofill password field.

Actually now the browsers ignoring the autocomplete="off" attribute. 

So I think the only workaround 'that I can come up with' is to add another fake password field; and just add it above your original password field. The browser will be confused when there is two password fields in the same block; so it will left them empty along with the name or email field .. 

I know we need to make the fake password some how invisible but actually the Odoo's invisible='1', will not achieve the desired result [it also equivalent to style="display:none"] the browser will still assume there is only one password. 

So I think we need to use style="visibility: hidden", but this one will make the label of the field still visible so you can make string = " " [space].

So your code will looks like:

<field name="fake_password" password="True" string = " " style="visibility: hidden"/>
<field name="password" password="True"/>

Still there may be another solution rather than this workaround ..

Hope this could helps ...