In March, SustainX raised $14.4m from seven investors, including GE Energy Financial Services and VC firms Cadent Energy Partners, Polaris Venture Partners and Rockport Capital Partners, as part of a then-planned $17m round.

SustainX, a US-based provider of batteries using compressed air, has raised $5.6m from venture capital firm General Catalyst Partners and its previous consortium to take the round’s total to $20m.

In March, SustainX raised $14.4m from seven investors, including GE Energy Financial Services and VC firms Cadent Energy Partners, Polaris Venture Partners and Rockport Capital Partners, as part of a then-planned $17m round.

GE Energy Financial Services, a unit of US-listed industrial conglomerate General Electric, last year said…