Things get capitalised when they are proper nouns (or proper names). Now, when something clears that bar is a local concern for an organisation. The general concept of an executive committee for a club or society would not require it to be capitalised, but within a given club they might choose to refer to their executive committee as the Executive Committee. A department of a large organisation might be capitalised within the organisation, but the idea of a science department isn't. Or the organisation might not treat department names as proper nouns.
A team within a team might be capitalised, that's up to the organisation involved. they might even capitalise the designation of the team-within-a-team without the word team, maing it "he is on the Electrical team". I would say the default is not to capitalise such things, because it is simply a description - the team that deals with the electrics. However, depending on organisational preferences, such units might be capitalised.