Dilemma and Breakthrough of Lithium Battery Manufacturing

Dilemma and Breakthrough of Lithium Battery Manufacturing

The upstream of the lithium battery industry chain is mainly suppliers of positive and negative materials, electrolytes, electrode substrates, separators and other fields; the midstream is the battery cell manufacturing and packaging industry; the downstream is mainly power batteries, consumer electronics and other lithium batteries. Application areas.

Figure 1: Industry chain of lithium battery industry

In recent years, with the continuous improvement of related technology and the continuous increase of penetration rate, the scale of my country's lithium battery market has grown rapidly. Data show that in 2019, my country’s lithium-ion battery output was 15.722 billion, a year-on-year increase of 12.40%. By October 2020, the output of lithium-ion batteries in my country was 14.635 billion, an increase of 10.9% year-on-year.

The rapid growth of the industry is an expected development trend. However, the development process is destined to be accompanied by challenges. How to break the situation and turn the predicament into a new opportunity has become the problem that most companies in the lithium battery industry face. At present, 95% of enterprises in my country's lithium battery industry are small and medium-sized enterprises, with small scale and low technical level. They mainly produce low-end lithium battery products. The "Notice on Adjusting and Improving Financial Support Policies for the Promotion and Application of New Energy Vehicles" implemented in June 2018 through subsidy measures indicated higher requirements for the energy density of new energy vehicle batteries, and low-end lithium batteries with overcapacity will be in the new era. Be gradually eliminated under the environment. At present, there are still many problems in the intelligent manufacturing of domestic power lithium batteries, which are mainly reflected in the following aspects:

First, at present, most of the hardware equipment of domestic lithium battery manufacturing enterprises is collected in sections, and there are problems of compatibility and diversity between equipment, resulting in low integration between various industrial software and data cannot be shared and circulated.

Second, the production and test data collection of lithium battery products is large, each process has different control requirements, and the manufacturing mode is a mixed mode of process and discrete, which intensifies the difficulty of industrial digitalization/intelligent manufacturing.

Third, the size and standard specifications of power batteries are not uniform. Domestic companies have produced more than 150 batteries of different specifications, resulting in a relatively small sales volume of a single model, which limits the development of standardized, large-scale and intelligent manufacturing.

Fourth, the product design and manufacturing process technology of power batteries are not fully mature, especially the key production process design of battery modules is immature, the verification is not sufficient, the one-time pass rate is low, and it is difficult to achieve online automatic testing and quality tracking. Therefore, the production of power battery systems is still dominated by semi-automation, and only a few battery manufacturers have realized the automated production of power battery modules or modules.

In the fierce market competition environment, lithium battery manufacturers not only need to continuously improve product quality and production efficiency, but also need to improve equipment flexibility, informationization and intelligence, so as to continuously shorten product development time and delivery cycle to adapt to the rapidly changing market surroundings. Therefore, it is no longer feasible to rely solely on automation for intelligent manufacturing of lithium batteries, and must be fully digitized and intelligent. A rich and comprehensive shared database needs to cover many fields from product design to production planning, engineering, production, and service, and integrate into suppliers and customers at the same time. High efficiency based on stability, flexibility and standardization based on modularization, and high automation and information based on the network are the core features of the future development of intelligent equipment for lithium battery production.

Time Does Not Wait: Future-oriented Intelligent Manufacturing of Lithium Batteries

Under the current system conditions, the lithium battery industry is under great pressure to deliver capacity, and product specifications are diversified. To adapt to the times and successfully transform, lithium battery manufacturers need to create flexible manufacturing models, shorten lead times, increase production capacity, and ensure quality. The "elasticity" and "flexibility" of intelligent manufacturing are the right tools to solve the uncertainty and complexity in the new market environment, which can meet the large-scale capacity expansion and adapt to different product specifications, so as to effectively control the cost of system ownership, which is beneficial to The lithium battery manufacturing industry is rapidly improving quality and efficiency and reducing costs.

Figure 2: Current status and goals of digital transformation

How to realize the intelligent manufacturing transformation of lithium battery enterprises?

Analysis of the main processes and concerns of the lithium battery industry

The production process of lithium batteries is divided into two stages, the process stage and the discrete stage.

Process segment

The process section is mainly to produce positive and negative materials, smearing and cutting. This section of the process equipment has a higher degree of automation and less manual participation. The product format is carried out in batch mode, so the manufacturing operation management in this section is mainly controlled in large quantities. For example, when the cathode material is stirred in vacuum, the workshop system records the barrel number of the mixing barrel, the batch number of the material added during mixing, and the mixing time. The related parameters and viscosity data of the equipment are also entered into the manufacturing operation management system immediately after the test. Production managers can easily understand the mixing status of each barrel of materials through the manufacturing operation management system. After production, they can also query the batch number of the batch of materials and the control parameter values ​​of the equipment during mixing. Relatively speaking, the cutting of the process section has little effect on the quality of the product.

Discrete segment

The discrete segment starts from the lamination/winding process, which is also the focus of the manufacturing operation management system in the control of the lithium battery production process. After the application of the manufacturing operation management system, the coding process will be preceded to the laminate. Because the quality of the battery is closely related to the temperature and pressure during the heat sealing of the heat sealer, recording the temperature and pressure during the heat sealing of the battery is also the main part of the system One of the tasks. After these data enter the manufacturing operation management system in real time, managers can know the parameter status, production output and quality status of each heat sealer through the system in real time, and provide a basis for production and quality decision-making in a timely manner. After this link is liquid injection and precharging, the data collection of the liquid injection process is mainly the heat sealing data collection after liquid injection, and the precharging mainly collects the relevant data of the bad cells during the sub-capacity, such as bar code, voltage, etc. The second refill mainly collects dispatch data and short-circuit data of the packaging film of the tab ear. The recharge mainly collects the data of the sub-capacity level.

The last is re-inspection and shipment. The battery is generally inspected at the AQL level during the re-inspection. After the manufacturing operation management system is connected to the testing equipment, the detected data will enter the system, and the system will automatically follow the set AQL inspection method. Receive or batch return, the inspection data will also be associated with the barcode. The packaging after re-inspection is also a focus of the application of the manufacturing operation management system in the battery industry, so as to obtain real-time accurate and detailed information about the packaging box number and the association relationship between the box number and all barcodes in the box.

In general, the main functions of MOM in the lithium battery industry are as follows:

1. Real-time quality monitoring, changing the post-remediation of quality problems to pre-prevention.

2. Process critical parameter monitoring to ensure the process safety of lithium batteries as much as possible.

3. Detailed records of the packaging, and be fully prepared to respond to customer complaints.

4. Real-time query of output and quality reduces the delivery pressure of the planning department.

5. Realize the traceability of the production process and quickly and accurately determine the scope of the recall.

6. Paperless production management, saving labor costs.

Figure 3: Process flow of lithium battery production

MOM goes first, empowering enterprises to upgrade their smart manufacturing

According to the process and characteristics of lithium battery production, companies can plan 9 core functions: advanced scheduling, digital process execution, production quality management, production execution, equipment management, industrial interconnection applications, lean billboards and production command centers, professional application apps, Master data and modeling.

Figure 4 MOM core function architecture diagram

The construction and implementation of an integrated MOM system can empower enterprises to transform and upgrade smart manufacturing, and continuously improve the automation level of business processes such as process management, planned production and execution, equipment interconnection, quality management, and logistics distribution. The integrated MOM system effectively combines IT and OT through equipment interconnection, improves the intelligent level of manufacturing equipment, realizes factory production automation, unmanned, and intelligent, and can greatly shorten the manufacturing cycle of enterprise-related products and reduce operating costs. Increase productivity.

Through the implementation of the MOM system, enterprises can consolidate the foundation of process, planning and execution, realize process modelling, refinement of planning, and transparency of execution; it will also complement the capabilities of distribution and interconnection to achieve precise distribution and interconnection of elements; in quality , Collaboration and management decision-making, to achieve comprehensive quality control, data standardization, and scientific decision-making.

What expected benefits can companies achieve through MOM?