In energy storage applications, high capacity cells of 280Ah and above can effectively reduce the cost of energy storage systems and reduce the difficulty of integration, with obvious advantages. It is gradually replacing the original 50Ah and 100Ah cell products in power storage scenarios. What is the difference between energy storage battery and power batteries?
According to different application scenarios, energy storage battery are mostly used in power systems, which require low cost and long life; power batteries mainly provide power for vehicles and pursue high energy density. Although the production lines of the two can be shared, with the rapid development of the energy storage industry, the scale of energy storage power stations is often at the 100 megawatt level or even the gigawatt level, and owners are calling for customized and specialized energy storage batteries.
1. High capacity energy storage batteries are the trend
In a set of electrochemical energy storage systems, the cost of batteries accounts for about 60%. In recent years, the scale of the energy storage industry has been expanding rapidly, and the pressure of cost reduction has been superimposed. The industry has put forward an urgent need for the high economy of energy storage battery. In 2020, CATL took the lead in launching 280Ah batteries with long cycle life, gradually replacing the original 50Ah-100Ah batteries and becoming the standard for energy storage project bidding or product procurement.
The mainstream battery manufacturers in the industry have followed suit and intensively launched 280Ah cells or even larger capacity cells. In May of this year, Cornex released a new product with a cell capacity of 280Ah and a single cell cycle life of more than 10,000 times. In August, HITHIUM released the first 300Ah special battery for electric energy storage and special battery for large cylindrical household energy storage. In October, EVE released a new generation of energy storage battery LF560K, which further pushed the battery capacity to 560Ah.
Energy storage lithium battery companies are accelerating their competition on the high-capacity cell track. Experts said that the development of special batteries for energy storage to larger capacity is one of the trends in technology iterations. High capacity batteries reduce the cost of energy storage systems by diluting the cost of battery structural parts, reducing the number of system components, simplifying the production line process, reducing the number of equipment, and reducing labor input.
2. Safety is the premise of energy storage industry development
Industry insiders believe that the current energy storage battery has entered a period of concentrated technological change. In addition to large capacity, high voltage and liquid cooling systems are gaining popularity in the market. At present, more and more manufacturers in China have started production and research and development of special production lines for energy storage battery. Home energy storage battery companies including EVE and GROW POWER have released special energy storage batteries to seize development opportunities.
It is worth noting that the research and development of energy storage battery must be based on safety, and the battery capacity is not blindly large. The battery capacity is too large to increase the safety risk. The increase of the capacity will lead to the deterioration of the heat dissipation performance of the battery itself. At the same time, high capacity batteries may have cell bulging problems, which will make it difficult to cope with overcharge and thermal runaway. It is necessary to make a balanced design for battery thermal management. Safety is the bottom line for the development of the energy storage industry.
Industry insiders emphasized that the current energy storage industry is still in the early stages of development, and the technical standards and acceptance standards are not perfect. It may be difficult for customers to identify various energy storage technologies and the pros and cons of their products. Under this circumstance, some incompetent enterprises blindly launch high capacity projects, increasing security risks. High capacity is not infinite amplification, but to achieve a balance between large capacity, high safety and long cycle life. So, which scenarios are suitable for small-capacity batteries, and which scenarios require high-capacity batteries?
The battery capacity is closely related to the installed capacity and application scenarios of the energy storage system/power station. For example, large-capacity storage systems are usually more suitable for matching high-capacity cells, which can greatly increase the energy density of the energy storage system, which is the development trend of the large-storage market, and small-capacity batteries for home energy storage are sufficient.
3. Energy storage battery manufacturing technology still needs to be improved
This year, the energy storage market demand is extremely strong, and the supply of 280Ah batteries is tight. For manufacturers, whether it is to build a new special energy storage battery production line or upgrade the original power battery production line, a certain expansion period is required. It is understood that the production of energy storage batteries mainly includes two processes: lamination and winding, which have a high degree of winding automation and high production efficiency. However, the requirements for the manufacturing process of 280Ah cells produced by winding are much higher than those of 50Ah-100Ah cells.
High-capacity batteries pose significant challenges to design and manufacturing capabilities. Industry experts said that small cells generally use the winding process, and the production efficiency is high, while large cells need to upgrade the production line to achieve the required technical parameters. How to ensure the safety, high efficiency and stability of electrochemical material filling in the production process is also the key. These are the problems that need to be solved urgently for energy storage battery. The production efficiency of large cells is lower than that of small cells, which is a law of physics. High-capacity batteries put forward new requirements for production equipment.
Taking HITHIUM's existing 280Ah intelligent production line as an example, the R&D and manufacturing team has carried out corresponding design and development on all process equipment in the assembly and test sections, and has done a lot of work. In the future, the creation of extremely fast production lines with higher production capacity remains to be continued by practitioners in technical research. In addition, the energy storage market has not yet reached the stage of large-scale development. The energy storage business model is not yet mature, and with the impact of upstream raw material price increases, battery companies are also more cautious in expanding production.