The consistency of lithium-ion battery and the life and quality assurance of power battery system are briefly described.

Lithium-ion battery consistency mainly refers to the consistent characteristics of the individual battery performance, including the consistency of the external characteristics(voltage, current, internal resistance), and the consistency of internal characteristics(capacity, power, and energy). Its main feature is that the chemical properties determine the electrical properties. Lithium-ion battery consistency runs through the series of clusters, systems, and customer applications from the production of the core to the core application. Until the later stage of utilization, each link needs to work hard around it, including cost investment.

Therefore, I divided it from the design point of view: the former consistency, mainly refers to the core from the material production process, such as material procurement, mixing, coating, drying and other production links, until the aging factory.

Post-consistency mainly refers to the design process of the group, which mainly includes the core starting from the series to the group, until the package, the system, and the design factors such as heat, machine, and electricity to ensure a high degree of consistency in the system's electrical performance.

On the one hand, this is controlled through the Module and Pack factories.

On the other hand, it depends on internal heat management and equilibrium to make adjustments.

In fact, there needs to be an additional link here, that is, application consistency, including the main use of vehicles, customer driving habits and so on. Here we focus on the discussion, as designers can control the key links, the guarantee of front and rear consistency and how to affect the battery system life, quality assurance factors.

From the point of view of parameter decomposition, the above part is the reason, and the degree of dispersion is measured. It is based on the factory and factory inspection and follow-up statistical parameters of the electric core enterprise.

Pre-consistency refinement, post-consistency scientific control

The main purpose of the core group is to increase capacity and increase energy. In the final analysis, it is to increase voltage and increase current. On the one hand, it adapts to the demand for energy and power of the whole vehicle; On the one hand, it directly matches the distribution drive system. At the same time, the process of increasing the voltage in Series conforms to the principle of "barrel"(calculation of capacity, power, and energy with the lowest performance core). Therefore, the difference between the best performance and the lowest performance of the core is smaller, and the performance is the fullest, and it is also the most conducive to the effective use of energy. However, as the number of system cycles increases and the time increases, this gap will become larger and larger until the capacity is lower than the threshold of 80 % and 70 % of the nominal capacity at the factory, and the power and electricity cannot meet the demand of the vehicle. Dynamism, mileage and life expectancy end. Below we can get a glimpse from a group of various manufacturers to the quality assurance committee of the vehicle products.

Power core lifetime quality assurance

The cases listed above illustrate why the manufacturers come to the quality assurance base? The main body is that the consistency of the core body has been very good(former consistency), plus the scientific control(post-consistency) of integrated design such as structural design, heat management, battery system management, and reliable electrical components after the system. The battery system can be perfect to meet the requirements of the complete vehicle life. At the same time, Tesla's reserve gas is also derived from its previous product, modelSODelX, which runs data: The vehicle mileage reaches 150,000 miles(240,000 kilometers). Most vehicle batteries are lost by less than 10 %.

How to control the former consistency

Several key factors for pre-consistent control: imported materials, production equipment, production environment, production process, testing, aging methods, screening processes, etc.. The more the front end, the lower the cost of input, the easier the back end. Control, sorting.

How to Control Post-Consistency

Lifetime insurance

The lifetime guarantee of the electric core, in addition to the manufacturers 'more marketing components, from a technical point of view, there is also a clear quality assurance description. Or it's a stupid book. Instead, it reduces the customer's recognition of the brand. Any product has a life span. The lack of quantitative warranty is a muddled account and ultimately cannot truly gain the trust of the customer.

Summary:

The consistency of the battery is a problem that can never be completely solved. However, through various technologies and control methods, it is possible to increase the level of consistency and increase the amount of electricity available. It is also an effective use of resources.

The page contains the contents of the machine translation.