From the Wikipedia page [1]
Nine Elms is a London Underground station in Nine Elms, London, as part of the Northern line extension to Battersea. The station was projected to open along with the rest of the extension in 2020, but in December 2018 Mayor of London Sadiq Khan announced the project's opening would be delayed for a year due to a need of "increasing the stations' capacities to a higher number of passengers than originally forecasted". The station opened on 20 September 2021 It serves the rapidly growing Nine Elms area, New Covent Garden Market and the new Embassy of the United States.
The new station is close to the site of the former Nine Elms Railway Station, once the terminus of the London and South Western Railway.