Ensuring high-quality production during commissioning and ramp-up : A case study at Northvolt

Abstract: Rechargeable lithium-ion batteries (LIBs) have generated a shift in the automotive industry towards electric vehicles (EVs) instead of vehicles powered by fossil fuels. As a result, the demand for LIBs is only expected to grow in the future due to an increased demand for passenger EVs. Consequently, LIB manufacturers have to increase their production to meet the increasing demand. Northvolt is a Swedish LIB manufacturer founded in 2016, aiming to start the production of LIBs at the Northvolt Ett factory in Skellefteå during 2021. The Northvolt Ett factory will be one of the largest battery plants in Europe, supplying battery cells for both commercial and domestic use. Poorly manufactured battery cells can potentially cause hazardous events, such as fires or explosions, further supporting the need for high quality batteries. Consequently, requirements from customers and industry standards are high in terms of product quality control through e.g. measurement system analysis (MSA), statistical process control (SPC), and capability analysis. Furthermore, previous research has highlighted issues during commissioning and ramp-up of production, potentially occurring at Northvolt Ett.  The purpose of this study has been to describe how high-quality production can be ensured and maintained during and after commissioning. The study has been conducted as a qualitative case study at Northvolt Ett, focusing on qualification of the coating process. The basis for the study was to examine previous research on quality assurance from other industries, analyze automotive standards, and gather learnings from the pilot production at Northvolt Labs in Västerås. Unstructured interviews were conducted with Northvolt staff to understand what had previously been done related to quality assurance for Coating.  The learnings from Northvolt Labs highlighted a clear focus on preventive actions, such as establishing a Design-FMEA, Process-FMEA, and a Control Plan for the coating process. However, room for improvement was identified in terms of process improvement and control, since the lack of SPC has yielded unreliable results from the performed capability analysis. In addition, previous research has shown that preventive actions should be combined with actions for process improvement to reach full-scale production quickly. Thus, recommendations have been made for Northvolt to implement a clear strategy for product qualification through SPC and capability analysis, as a complement to the preventive actions. The recommendations include specific propositions for validation of the coating process and a general framework for process validation through MSA, SPC, and capability analysis. The presented recommendations can help Northvolt perform successful commissioning of the processes at Northvolt Ett and can also be useful for process validation in other manufacturing industries.