Evaluation of Battery Manufacturing
Lithium-ion batteries are manufactured by means of electrode fabrication and battery assembly process steps. During this manufacturing process, batteries are exposed to all sorts of physical and thermal stresses. Even after batteries are completed, electrochemical reactions associated with charging-discharging change the internal state of batteries. This page describes techniques for evaluating batteries in the composite state, assembled from various raw materials, and describes instruments and solutions available for checking product quality.
Battery materials are manufactured in sheet form by fabric roll-to-roll processing methods. Positive and negative electrodes are manufactured by coating a current collector with an electrode material and drying the coating. Then the coated material is cut into strips by a slitting process. Separators are manufactured as a polymer film. For this reason, evaluating composite electrode materials manufactured by a variety of process steps requires different evaluation criteria than for evaluating the individual raw materials separately.
The various electrode materials manufactured by electrode manufacturing process steps are laminated and rolled together before being assembled into a battery cell. After inserting the rolled materials into a cell, the cell is sealed by welding and injected with electrolyte solution. Assembled battery cells are treated by an aging process that applies an initial charge. Non-destructive analysis of the assembled cell and analysis of the gases generated during the aging process can be expected to increase the reliability of battery products.