Potentials and Implementation Strategies For Flexible Battery Cell Production

Abstract

The effects of a fossil fuel-based economy are becoming increasingly apparent. The storage and use of renewable energy sources are a key strategy to reduce overall greenhouse gas emissions. In this context, the demand for batteries as a suitable medium for energy storage is increasing rapidly. Lithium-ion batteries pioneered in consumer electronics are nowadays used in ever more applications, with the e-mobility sector being one of the most prominent. From a production perspective, the process chain for manufacturing of such lithium-ion batteries can be divided into three main sections: electrode production, cell assembly and cell finishing. However, actual implementation of the process chain differs substantially, depending on the selected cell format (pouch, cylindric, prismatic) and design, manifesting in cell-specific processes (e.g. stacking vs. winding), supplementary and/or omitted process steps and manufacturing technologies (e.g. pouch foil heat sealing vs. hard case laser welding). Currently there is no strictly preferred cell format, as each format has its advantages and disadvantages, depending on its intended application and system integration. Production of different battery cell types thus is spread across various international mostly Asian manufacturers, most of which have large scale mass production lines dedicated to a single specific format. Only a few manufacturers have a portfolio of formats (e.g. round and prismatic) in large quantities. Against this background, the following paper provides an overview of the product variety of lithium-ion batteries available on the market, following up with a discussion of potentials and implementation strategies for flexible battery cell production. First, applications and business areas for lithium-ion batteries are analysed and general flexibility areas regarding the battery cell design are derived. Subsequently, the impacts of the different flexibility areas on the production processes are analysed. In a final step, different implementation strategies and approaches for increased flexibility in battery cell production are elaborated.