The proliferation of rechargeable lithium-ion batteries used in a wide range of applications has moved the technology clearly into the public eye. Debate about various battery types, their properties, cost and performance have become popular topics in private and professional discussions.
However, most of these discussions tend to put an excessive emphasis on the chemistry of the cells in the batteries. For example, whether a lithium iron phosphate battery is safer than a lithium-nickel-manganese-cobalt battery. In truth, battery performance is affected by not just one, but up to five primary factors: cell chemistry, cell geometry, manufacturing quality, matching technology to application, and system integration.
Cell chemistry is considered to be the “tip of the iceberg”. It is the most visible characteristic, but the actual performance of battery systems in real-world applications seldom depends to a large degree on the cell chemistry. More often it is one of the other five factors.
Manufacturing quality is one of the most critical factors, but also least discussed. The cause for this is likely that cell chemistry and geometry can easily be discussed based on the multitude of information available in the public domain. Matching of the most suitable battery chemistry to the application is a topic that can be simulated and discussed with modern computing tools. Manufacturing and manufacturing quality, however, is typically an in-house secret of each manufacturer – and often exposes clear differences between manufacturers even when using the same chemistries. There is little incentive for manufacturers to have details about their manufacturing processes published in any form.