What is a lithium battery box?

Introduction

What is a lithium battery box? Battery box generally refers to assembled batteries, also known as battery pack.

There are two kinds of battery pack is implemented. Is a kind of laser welding, ultrasonic welding, or pulse welding. This is a commonly used welding method.

The advantage is good reliability, but it is not easy to change. The second is contact through an elastic metal plate. As the trend of division of labor in production becomes more and more obvious, the lithium-ion battery PACK industry has gradually started and achieved rapid development.

What is a lithium battery box?

The battery pack generally refers to packaging, packaging and assembly. For example, if two batteries are connected in series, and the customer requires a certain shape, we call it pack. In the battery industry, not use the battery assembly and can be directly is often referred to as the battery, and connect to the PCM board and charging and discharging control of battery products is called the battery.

The PACK group process is a key step in the production of lithium-ion battery packs, and its importance is becoming more and more obvious with the continuous expansion of the electric vehicle market. At present, automotive lithium-ion batteries are basically composed of the following systems: battery modules, battery management systems, thermal management systems, electrical and mechanical systems.

Battery PACK are now mainly concentrated in lithium battery PACK factories. They all have their own PACK structure design, PACK electronic design and PACK production workshops. They can carry out independent development and design according to customer needs, through battery solutions, battery specifications, and battery samples. After the customer’s PACK lithium battery customization requirements are confirmed, the PACK production line in the PACK workshop is processed, and the quality inspection is passed and the shipment is passed.

Lithium-ion battery pack process introduction

Assembly process

The assembly process of PACK is actually somewhat similar to the engine assembly process of traditional fuel vehicles. These five systems through the bolt, nut, cable tie, fixtures, wiring harness with nail and other connector to connect together, form an assembly.

Air tightness testing process

The power battery PACK is generally installed under the seat of a new energy vehicle or under the trunk, and is directly in contact with the outside world. When high-voltage electricity comes into contact with water, you can imagine the consequences of things through common sense. Therefore, when the new energy vehicle is wading through the water, the battery PACK needs to have good airtightness.

Software flashing process

The component flashing process is to flash the BMS control strategy into the CMU and BMU in the BMS in the form of code, so that the battery status information data collected during the battery test and use process will be processed and analyzed by the electronic control unit. Then, according to the analysis results, control instructions are issued to the relevant function modules in the system, and finally the information is transmitted to the outside world.

Electrical performance testing process

The electrical performance testing process is the testing process that must be done after the above three processes are completed, that is, before the product goes offline. Including insulation testing, charging status testing, fast and slow charging testing, etc.

Development prospects of lithium battery box

The global lithium battery box market is mainly monopolized by Japan, South Korea and China, and its lithium-ion battery production capacity accounts for more than 95% of the world. Calculated according to the battery energy density of 300Wh/kg and Pack energy density of 260Wh/kg, the integration efficiency of the Pack system should be 85%, while the current passenger car Pack integration efficiency is generally around 65%, which means integration Efficiency needs to be greatly improved to achieve the goal.

To improve the efficiency of Pack integration, there are two feasible ways. One is to optimize the internal structural design of the Pack, greatly reduce the number of components inside the Pack, and integrate more components and functions on the modules and cabinets, thereby reducing Weight; the other is the use of lightweight materials, such as aluminum or composite materials instead of high-strength steel, plastic parts instead of metal parts, etc., which can also reduce weight.

Lithium-ion battery PACK is relatively a technology-intensive industry. In the next five years, the growth rate of the lithium-ion battery PACK industry will remain at a level of about 30%. By 2023, the global lithium-ion battery PACK market will reach 186.3 billion US dollars.

The characteristics of lithium-ion battery PACK

1. There are complete functions, which can be directly applied; the variety of types, the same application requirement can be realized by multiple PACK.

2. Lithium-ion battery pack PACK requires batteries to have a high degree of consistency (capacity, internal resistance, voltage, discharge curve, life).

3. The cycle life of the lithium-ion battery pack PACK is lower than the cycle life of a single battery.

4. Use under limited conditions (including charging, discharging current, charging method, temperature, humidity conditions, vibration, force level, etc.)

5. The PACK protection board of the lithium-ion battery pack requires a charge equalization function.

6. High-voltage, high-current battery packs PACK (such as electric vehicle batteries, energy storage systems) require communication buses such as battery management systems (BMS), CAN, and RS485.

7. Lithium-ion battery pack PACK has higher requirements for chargers, and some requirements communicate with BMS. The purpose is to make the battery to work properly, make full use of the energy stored in the storage battery, ensure safe and reliable to use.

Conclusion

As the main battery used in new energy vehicles, lithium-ion batteries will usher in a golden development opportunity period driven by policies. The battery box industry will also get more development opportunities in the good situation of power batteries. In addition, as technology constantly updated and breakthrough, business model of exploration and innovation, the lithium ion battery industry will also usher in new technology, new model driven by a higher growth rate.