Try
= f.button :submit, input_html: { id: 'edit_account' }
From docs:
If you want to pass the same options to all inputs in the form (for example, a default class), you can use the :defaults option in simple_form_for. Specific options in input call will overwrite the defaults:
<%= simple_form_for @user, defaults: { input_html: { class: 'default_class' } } do |f| %>
<%= f.input :username, input_html: { class: 'special' } %>
<%= f.input :password, input_html: { maxlength: 20 } %>
<%= f.input :remember_me, input_html: { value: '1' } %>
<%= f.button :submit %>
<% end %>
Since Simple Form generates a wrapper div around your label and input by default, you can pass any html attribute to that wrapper as well using the :wrapper_html option, like so:
<%= simple_form_for @user do |f| %>
<%= f.input :username, wrapper_html: { class: 'username' } %>
<%= f.input :password, wrapper_html: { id: 'password' } %>
<%= f.input :remember_me, wrapper_html: { class: 'options' } %>
<%= f.button :submit %>
<% end %>