Advancements in manufacturing

Lithium ion battery (LIB) manufacturing was established in the 1990s by Sony; however, advancements in the processes and the scientific understanding of those processes upon the final cell performances are still being understood. A standard process for LIB manufacturing includes: ink mixing, coating and drying, cell construction and design, and the formation and conditioning steps. The material properties determine the mixing methodologies, and hence the dispersion of the particles in a mix or a slurry. Advancements in mixing technologies have been observed at large scale with a continuous process, however at small scale high energy and high torque mixing are still the main mixing methods. The main coating technology for thick electrode lithium ion cells is the slot die or comma bar techniques; alternative techniques such as electrostatic sprayings, and electrophoretic coatings are still mainly used for thinner electrode coatings. Advancements are being made in electrostatic dry coating and laser technologies. One of the most costly manufacturing procedures is the formation and conditioning step, and this process can be shortened by short high voltage cycling rather than complete cycles. Due to the complex interplay of each process upon the final design, structure and hence properties of the lithium ion battery, when one parameter is changed, it can affect the final performance of the cell. The knock-on effects of the parameter changes are not completely understood until a cell has been manufactured and tested. This chapter discusses the manufacturing aspects of lithium and sodium ion batteries and the recent advancements in technology.