Lithium-ion battery consistency refers to the consistent characteristics of single-cell performance, including the consistency of the characteristics of the battery, the consistency of the internal characteristics (capacity, power, energy) .The main feature is determined by the chemical properties of electrical properties. Lithium-ion battery consistency runs through the series from the production of batteries to the application of batteries and the system, the customer application, until the later step of the use of cascade, each link needs to work hard, including cost inputs.
Therefore, I design from the point of view of the division: the former consistency, mainly refers to the core material from the beginning of the production process, such as material procurement, mixing, coating, drying and other production processes, until the aging of the factory.
After the consistency mainly refers to the design process into a group, including the batteries from the beginning of the series into the group until the package body, system, from the heat, mechanical, electrical and other design factors to ensure that a high degree of consistency of the electrical properties of the system.
On the one hand this is controlled by the Module and Pack factories.
On the other hand, internal thermal management and balance adjustment.
In fact, there is a need to add an additional link, that is, the application of consistency, including the main vehicle area, customer driving habits, etc. Here we focus on the discussion, as a designer can control the key aspects of before and after the consistency of assurance and How to affect battery life, warranty factors.
From the parameter decomposition point of view, the above part is the reason, the measure of dispersion is based on the battery factory and Pack enterprises into the factory and factory inspection and follow-up tracking statistics parameters to achieve.
Consistency before the consistency, after the consistency of scientific control
The main purpose of the battery pack group to enhance capacity and improve energy, in the final analysis is to enhance the voltage and increase current. On the one hand to adapt to vehicle energy and power requirements; on the one hand directly to match the electric drive system. At the same time, in series to enhance the voltage Process, but also in line with 'wooden barrel' principle (with the performance of the lowest batteries for the capacity, power, energy calculation.) Therefore, the best performance batteries with the lowest performance batteries smaller gap between the release of the most complete performance, and most But with the increase of system cycle times and the increase of time, the gap will become bigger and bigger until the capacity is lower than 80% and 70% of the nominal capacity of the factory, and the power, Electricity can not meet the needs of the vehicle power, mileage and end of life. Here we from a group of manufacturers on the vehicle product quality assurance promise can be seen.
The cases listed above, manufacturers come to warranty emboldened? Body is the consistency of the cell body has been very good (before the consistency), together with the group into the system after the structural design, thermal management, battery system management, reliable electrical Components and other integrated design of the scientific control (after the consistency), the battery system can naturally be the perfect match with the vehicle life expectancy.At the same time, like the bottom of Tesla also comes from its predecessor model S Model X operating data: vehicle mileage reached 15 Most of the vehicle batteries in a million miles (240,000 kilometers) lost less than 10%.
How to control the consistency of the former
Before the consistency control of several key factors: the entrance of the material, production equipment, production environment, production technology, testing, aging methods and the length of time, the screening process, the more the front end, the lower the cost of investment, the back end of the more easy to control , sorting.
How to control the consistency after
Lifetime warranty
Life-long cell warranty, in addition to the manufacturers more marketing components, from a technical point of view, but also need to have a clear description of the warranty, otherwise it is a muddle-headed account, but reduce the customer's brand recognition.Any The product is the use of the deadline.No quantified warranty is a mess account, ultimately unable to obtain the true sense of customer trust.
summary:
The consistency of the battery is a problem that can never be completely solved, but various technologies and control measures can be used to increase the level of consistency, increase the amount of power available, and make effective use of resources.
