Under the deal, Siemens will provide its "Digital Enterprise" software portfolio, allowing Northvolt to benefit from Siemens' digitalisation solutions and "optimise its battery production", Siemens said.
In return, once Northvolt's factory in Sweden is competed in 2020, it will become Siemens' preferred battery supplier.
"With our Digital Enterprise portfolio, we contribute to a competitive battery cell production in Europe that fully exploits the benefits of software and automation: greater flexibility, efficiency and quality with shorter time to market", said Jan Mrosik, CEO of Siemens Digital Factory Division.
Peter Carlsson, CEO of Northvolt, added: "The European industry is moving rapidly towards electrification. Siemens will become an important technology partner, supplier and customer to Northvolt in this coming transition. Once we begin large-scale production, our aim is to supply the greenest lithium-ion batteries in the world."
In December, Danish turbine manufacturer Vestas invested €10 million in Northvolt for a seven-year project to develop a lithium-ion platform suited to wind projects.
Previously, grid firm ABB signed a collaboration agreement with Northvolt in September 2017, to share products and services. Northvolt has also received backing from Swedish utility-developer Vattenfall.