What is lithium-ion power battery pack and its composition

As a high-voltage battery, lithium batteries are favored by 3C digital, power tools and other industries because of their high energy density, environmental protection, long life, fast charging and other advantages, and their contribution to the new energy automotive industry is particularly prominent.Battery recycling machine Next, we will help you understand the classification, composition, process and production line of lithium-ion power battery pack.

Classification of lithium-ion power battery pack

1. What is a lithium-ion power battery pack

The general difference between lithium battery cells, lithium battery modules and lithium-ion power packs:

Battery monomer: the most basic element that constitutes the battery lithium-ion power pack and battery lithium-ion power pack, generally available voltage between 3v-4v;

Battery lithium-ion battery: a collection of multiple monomers together to form a physical module,cylindrical battery pack mahcine providing higher voltage and capacity.

Battery Li-Ion Power Packs: generally consisting of multiple battery Li-Ion power packs. Also added is the battery management system (bms), which is the final product provided by the battery manufacturer to the user.

As the core component of the lithium-ion power pack, currently according to the shape of the battery is mainly divided into three categories: prismatic shell, cylinder and soft lithium-ion power pack (polymer battery).cell stacking machine Positive and negative electrodes are encapsulated in different ways in the corresponding shells.

2.Battery Module

By assembling single cells, the cells are formed into different series and parallel connections via busbars, which can be screw-welded, resistance-welded, ultrasonic-welded, ultrasonic-aluminum wire-welded and laser-welded. Laser welding is currently the preferred choice of many battery manufacturers, considering production yields, efficiency and internal resistance at the connection points.

Components of lithium-ion power battery packs

It mainly consists of battery module, mechanism system, electrical system, thermal management system and BMS.

1. Battery Module

The battery module is responsible for storing and releasing energy to power the vehicle.

2.Mechanism system

It mainly consists of battery lithium-ion power pack top cover, tray, various metal brackets, end plates and bolts, which play the roles of support, anti-mechanical shock, mechanical vibration and environmental protection (waterproof and dustproof).

3.Electrical system

It mainly consists of high-voltage jumper wire or high-voltage harness, low-voltage harness and relay. The high-voltage harness can be regarded as the "artery" of the lithium-ion power battery pack, which transmits the heart power of the power battery system to each required component continuously.

The low-voltage wiring harness can be regarded as the "neural network" of the lithium-ion power battery pack, which transmits detection signals and control signals in real time.

4. Thermal Management System

There are four main types of thermal management systems: air cooling, water cooling, liquid cooling and phase change materials. Taking the water-cooled system as an example, the thermal management system mainly consists of cooling plates, cooling water pipes, heat-insulating pads and heat-conducting pads.

5.BMS

Battery management system is mainly composed of CMU and BMU.

CMU: Battery monitoring unit, which is responsible for measuring parameters such as voltage, current and temperature of the battery, as well as functions such as balancing. When the CMU measures these data, it transmits them to the BMU through the battery "neural network" mentioned earlier.

BMU: Battery Management Unit The Battery Management Unit. It is responsible for evaluating the data transmitted by the CMU. If the data is abnormal, it protects the battery by issuing a request to reduce the current or cut off the charging and discharging paths to prevent the battery from exceeding the permissible conditions of use, and also manages the power and temperature of the battery.

Based on the previously designed control strategy, it determines the parameters and states that need to be alarmed and sends the alarm message to the vehicle controller and finally communicates it to the driver. Below are the top 10 battery management system suppliers in question.

Process

Battery lithium-ion power packs are the core energy source of new energy vehicles, providing the driving force for the entire vehicle. As a core component of new energy vehicles, its quality directly determines the performance of the entire vehicle. Lithium battery manufacturing equipment is generally divided into three types: front-end equipment, mid-end equipment and back-end equipment.

The precision and automation level of the equipment will directly affect the production efficiency and consistency of the product. Although the types of cells and modules are different, the composition and process of lithium-ion power battery packs are generally the same. It is mainly divided into assembly process, air tightness testing process, software writing process, electrical performance testing process, etc.

Introduction of production line

The assembly process of lithium-ion power battery pack has a lot of flexible circuits and press-fit fastening. Automation is difficult and the input-output ratio is not high. Therefore, the degree of automation of the back-end equipment will be lower than that of the front and middle sections, but it is compatible with three types of lithium-ion power pack batteries in cylindrical, prismatic case, and flexible lithium-ion power pack.

Back-end lithium-ion power pack production line mass production equipment mainly has two operation modes: AGV + assembly trolley, mainly used in automobile factories in the past, and now battery factories are also slowly promoting this mode; conveyor line + tray mode, roller line / roller friction line / multi-chain conveyor line.

With the gradual maturation of the development of the power battery industry, the modular technology of lithium-ion battery pack will also become more and more mature. The development of lithium-ion power battery pack technology involves multidisciplinary and multidisciplinary knowledge, requiring interdisciplinary technology integration.

Power battery companies, including automotive companies to mass produce power battery pack products that fully meet the requirements of new energy vehicles in terms of longevity, stability, reliability, safety, etc., a large number of engineering practices and experimental verification is required. And the continuous optimization and upgrading process of products.