Fiumicino doesn't publish a count or map of fixed wall outlets, but it does run one specific, named charging service worth knowing about if your battery is running low before a long flight.
Free powerbank rental in Boarding Area E
Aeroporti di Roma runs a free powerbank-rental program in Boarding Area E: 28 stations, each holding up to 30 powerbanks. You take a card-secured deposit hold, pick one up at any station, and return it at any station — not necessarily the one you took it from — so it works even if your gate changes.
Wall outlets elsewhere
Outlets exist around seating areas and gates as in most modern terminals, but the airport doesn't publish specifics on locations or counts. If you're not near Boarding Area E, bringing your own portable charger is the more reliable option.
Best places to look for outlets
As a general pattern at renovated airports like Fiumicino's Terminal 1 pier, outlets tend to cluster around gate seating banks and any dedicated workstation-style counters rather than being spread evenly throughout. Checking near the gate area itself, rather than in open circulation space, is usually more productive than wandering.
Charging while you eat or shop
Sit-down restaurants and lounges are a reliable fallback if you can't find a free outlet nearby — many seating areas in cafés and lounges include outlets built into tables or nearby walls, so combining a coffee or meal with a charge is often more efficient than searching gate areas specifically for a free plug.