Recently, CCTV’s report of “charging for one hour and queuing for four hours” has sparked heated discussions. The battery life and charging issues of new energy vehicles have once again become a hot issue for everyone. At present, compared with traditional liquid lithium batteries, solid-state lithium batteries with higher safety, greater energy density, longer battery life, and wider application fields are widely considered by industry insiders as the future development direction of lithium batteries. Companies are also competing for layout.
Although the solid-state lithium battery cannot be commercialized in the short term, the research and development process of solid-state lithium battery technology by major companies has been getting faster and faster recently, and the market demand may promote the mass production of solid-state lithium battery ahead of schedule. This article will analyze the development of the solid-state lithium battery market and the process of preparing solid-state lithium batteries, and take you to explore the automation market opportunities that exist.
Solid-state lithium batteries have significantly better energy density and thermal stability than liquid lithium batteries
In recent years, the continuous innovation in the downstream application field has put forward higher and higher requirements for the lithium battery industry, and the lithium battery technology has also been continuously improved, moving towards higher specific energy and safety. From the perspective of the development path of lithium battery technology, the energy density that liquid lithium batteries can achieve has gradually approached its limit, and solid-state lithium batteries will be the only way for the development of lithium batteries.
According to the “Technical Roadmap for Energy Saving and New Energy Vehicles”, the energy density target of power batteries is 400Wh/kg in 2025 and 500Wh/kg in 2030. In order to achieve the goal of 2030, the existing liquid lithium battery technology route may not be able to shoulder the responsibility. It is difficult to break the energy density ceiling of 350Wh/kg, but the energy density of solid-state lithium batteries can easily exceed 350Wh/kg.
Driven by market demand, the country also attaches great importance to the development of solid-state lithium batteries. In the “New Energy Vehicle Industry Development Plan (2021-2035)” (Draft for Comment) released in December 2019, it is proposed to strengthen the research and development and industrialization of solid-state lithium batteries, and raise solid-state lithium batteries to the national level, as shown in Table 1.
Table 1 Comparative analysis of liquid batteries and solid-state batteries
Not only for new energy vehicles, the energy storage industry has broad application space
Influenced by the promotion of national policies, the rapid development of the new energy vehicle industry will provide a broad development space for solid-state lithium batteries. In addition, all-solid-state lithium batteries are also recognized as one of the emerging technology directions that are expected to break through the bottleneck of electrochemical energy storage technology and meet future development needs. In terms of electrochemical energy storage, lithium batteries currently account for 80% of electrochemical energy storage. The cumulative installed capacity of electrochemical energy storage in 2020 is 3269.2MV, an increase of 91% over 2019. Combined with the country’s guidelines for energy development, the demand for electrochemical energy storage in the user-side, renewable energy grid-connected facilities and other fields is expected to usher in rapid growth, as shown in Figure 1.
Sales and growth of new energy vehicles from January to September 2021 Cumulative installed capacity and growth rate of chemical energy storage projects in China from 2014 to 2020
Figure 1 Sales and growth of new energy vehicles; cumulative installed capacity and growth rate of chemical energy storage projects in China
Enterprises speed up the research and development process, and China generally prefers oxide systems
In recent years, the capital market, battery companies and major car companies have all begun to increase the research layout of solid-state lithium batteries, hoping to dominate the competition in the next-generation power battery technology. However, according to the current progress, it will take 5-10 years for all-solid-state lithium batteries to be mature in science and manufacturing technology before mass production. International mainstream car companies such as Toyota, Volkswagen, BMW, Honda, Nissan, Hyundai, etc. are increasing their R&D investment in solid-state lithium battery technology; in terms of battery companies, CATL, LG Chem, Panasonic, Samsung SDI, BYD, etc. are also continuing to develop .
All-solid-state lithium batteries can be divided into three categories according to electrolyte materials: polymer solid-state lithium batteries, sulfide solid-state lithium batteries, and oxide solid-state lithium batteries. The polymer solid-state lithium battery has good safety performance, the sulfide solid-state lithium battery is easy to process, and the oxide solid-state lithium battery has the highest conductivity. At present, European and American companies prefer oxide and polymer systems; Japanese and Korean companies led by Toyota and Samsung are more keen on sulfide systems; China has researchers in all three systems, and generally prefer oxide systems, as shown in Figure 2.
Figure 2 The production layout of solid-state lithium batteries of battery companies and major car companies
From the perspective of research and development progress, Toyota is recognized as one of the most powerful players in the field of solid-state lithium batteries in foreign countries. Toyota first proposed relevant developments in 2008 when it cooperated with Ilika, a solid-state lithium battery start-up. In June 2020, Toyota’s electric vehicles equipped with all-solid-state lithium batteries have already carried out driving tests on the test route. It has now reached the stage of obtaining vehicle driving data. In September 2021, Toyota announced that it would invest $13.5 billion by 2030 to develop next-generation batteries and battery supply chains, including solid-state lithium batteries. Domestically, Guoxuan Hi-Tech, Qingtao New Energy, and Ganfeng Lithium Industry established small-scale pilot production lines for semi-solid lithium batteries in 2019. In September 2021, Jiangsu Qingtao 368Wh/kg solid-state lithium battery passed the national strong inspection certification, as shown in Table 2.
Table 2 Solid-state battery production plans of major enterprises
Process analysis of oxide-based solid-state lithium batteries, hot pressing process is a new link
The difficult processing technology and high production cost have always restricted the industrial development of solid-state lithium batteries. The process changes of solid-state lithium batteries are mainly reflected in the cell preparation process, and their electrodes and electrolytes have higher requirements for the manufacturing environment, as shown in Table 3.
Table 3 Process analysis of oxide-based solid-state lithium batteries
1. Introduction of typical equipment – lamination hot press
Model function introduction: The lamination hot press is mainly used in the synthesis process section of all-solid lithium battery cells. Compared with the traditional lithium battery, the hot pressing process is a new link, and the liquid injection link is missing. higher requirements.
Automatic product configuration:
• Each station needs to use 3~4 axis servo motors, which are used for lamination lamination and gluing respectively;
• Use HMI to display the heating temperature, the heating system needs a PID control system, which requires a higher temperature sensor and requires a larger amount;
• The controller PLC has higher requirements on control accuracy and shorter cycle period. In the future, this model should be developed to achieve ultra-high-speed hot-pressing lamination.
Equipment manufacturers include: Xi’an Tiger Electromechanical Equipment Manufacturing Co., Ltd., Shenzhen Xuchong Automation Equipment Co., Ltd., Shenzhen Haimuxing Laser Intelligent Equipment Co., Ltd., and Shenzhen Bangqi Chuangyuan Technology Co., Ltd.
2. Introduction of typical equipment – casting machine
Model function introduction: The mixed powder slurry is supplied to the casting head through the automatic feeding system device, and then applied by scraper, roller, micro-concave and other coating methods according to the process requirements, and then dried in the drying tunnel. The base tape together with the green body can be used for rewinding. After drying, the green body can be peeled off and trimmed, and then cut to the width specified by the user to cast a film material blank with certain strength and flexibility.
Automatic product configuration:
• Servo is mainly used for rewinding and unwinding, rectifying deviation, and tension controller is required to adjust the tension at the rewinding and unwinding place;
• Use HMI to display heating temperature, heating system needs PID control system;
• The fan ventilation flow needs to be regulated by a frequency converter.
Equipment manufacturers include: Zhejiang Delong Technology Co., Ltd., Wuhan Kunyuan Casting Technology Co., Ltd., Guangdong Fenghua High-tech Co., Ltd. – Xinbaohua Equipment Branch.
3. Introduction of typical equipment – sand mill
Model function introduction: It is optimized for the use of tiny grinding beads, from flexible dispersion to ultra-high energy grinding for efficient work.
Automatic product configuration:
• Sand mills have relatively low requirements for motion control, generally do not use servos, but use ordinary low-voltage motors for the sanding production process;
• Use the frequency converter to adjust the spindle speed, which can control the grinding of materials at different linear speeds to meet the different grinding fineness requirements of different materials.
Equipment manufacturers include: Wuxi Shaohong Powder Technology Co., Ltd., Shanghai Rujia Electromechanical Technology Co., Ltd., and Dongguan Nalong Machinery Equipment Co., Ltd.
Post time: May-18-2022