Cell Supply Chain Management with Approval and Surveillance Program

Abstract

Although many battery safety standards and certifications are in place to minimize hazards or prevent safety-related incidents in the field, many publicized field incidents have increased public concerns about LiB safety. Most battery field incidents reported that the cell internal short circuit initiated the causes, and many experts blamed battery industries do not have the test system that can predict the field incident nor reflect how the incidents occur. The certification is required when a cell model is developed and just before that goes into the market.Some intended or unintended modifications are in the cell model after the model is certified, and some failure analysis reports blame unknown and unproven changes on the cell model were the root causes of the incidents.To eliminate and prevent the root causes of battery field incidents by unknown and unproven changes on the cell model, we developed a verification process named cell supply chain management with approval and surveillance program. The verification process makes a technical database of all the analysis and test results of each step of a cell model as its fingerprint. The database enables the process can identify and prevent any unknown and unproven changes in the cell model through its life span.The verification process has: 1) Cell electrical properties, 2) X-ray investigation and Destructive Physical Analysis with -electrode alignment check with overhang gap, - electrode assembly (Jelly roll) function and dimension measurement, - insulation mechanism check and measurement, 3) Electrode dimension measurement and composition and materials analysis, and 4) Electrolyte composition analysis.This paper explains and proposes the concept and analysis method of each verification process and validates the cell model verification process by comparing the analysis results of each step of a cell model manufacturing. Figure 1