Battery separator refers to a layer of separator material between the positive and negative electrodes of the battery. Grepow Battery will study the development trend of lithium-ion battery separator from the research direction of the diaphragm and the improvement of diaphragm performance.
What is the lithium-ion battery separator
It is a very critical part of the battery. It has a direct impact on battery safety and cost. Its main function is to isolate positive and negative electrodes and prevent electrons in the battery. Free passage, allowing ions in the electrolyte to pass freely between the positive and negative electrodes. The ion conductivity of the battery separator is directly related to the overall performance of the battery. The function of isolating the positive and negative electrodes can limit the increase of current in the case of overcharging or temperature increase, preventing the battery from short-circuiting and causing an explosion. Self-closing protection, which protects battery users and equipment.
Research direction of separator
To improve product yield
Due to the oversupply of the market, the price of the separator has led to a sharp decline in the profit margin of the separator companies. In the case of unfavorable external markets, enterprises must find ways to save themselves. Which company can have a higher yield rate and lower production costs, which company can survive in the fierce market competition, and improving the yield rate has become a top priority for enterprises.
Improve the heat resistance of the separator
The advancement of technology, the development of society, and the safety issue will inevitably be more and more valued by society. Therefore, to solve the heat resistance of the separator, who can produce a separator that can remain intact after a large area ofpositive and negative short circuits in the process of charge and discharge. Sexual high-temperature composite separator, whoever takes the lead, who is likely to dance with companies like Tesla;
Develop ultra-thin separator
With the development of the market, thinner and smaller 3C electronic products will continue to enter our lives. These products require thinner battery separators to make batteries. At the same time, the pursuit of the capacity of lithium batteries also requires thin film. The direction of development. However, the production and preparation of ultra-thin diaphragms have high requirements for equipment and processes. If the company can master the production technology of ultra-thin diaphragms, it will be in a very powerful position in the future competition.
Improve the liquid absorption performance of the separator
At present, the capacity problem of lithium-ion batteries has become more and more prominent. Whether it is a smartphone or a power car, the contradiction between standby time or cruising range and consumer demand is increasingly prominent. If companies are not able to make better breakthroughs in ultra-thin battery separators, they can find ways to improve the liquid absorption performance of the separator, because improving the liquid absorption performance can also increase the battery capacity.
Develop new separator products such as polymer electrolyte separator and fiber separator
Studying these separators has certain risks because the experience of China’s reform for more than 30 years tells us that the method of imitating follow-up is relatively easy to succeed, and the way to create inventions is more frustrating. If you can open up a new way through your own efforts, will become the benchmark of the industry, and profits are unimaginable.
Different types of separators characteristics：
|1||Ultra-thin separator||3C batteries||Thin thickness, increased battery energy density, etc.||Decreased safety|
|2||Polymer battery separator||Soft pack battery||Excellent liquid absorption and liquid retention performance, improved battery cycle performance, etc.||Increased cost and heat resistance needs to be improved|
|3||Ceramic coated separator||Power battery||Excellent heat resistance, improved separator wettability, etc.||Increased cost|
|4||New separator||Power battery||Excellent heat resistance, improved separator wettability, etc.||Hole size and uniformity need to be improved|
Improve separator performance
Functional coatings are added to the PP film and PE film
To meet special needs such as high-temperature characteristics. The functional coating not only improves the heat resistance of the separator but also solves the electrolyte-friendly properties of the separator. The formulation and coating form used by various companies are different.
Blending PE or PP film with inorganic or organic materials
Another method for improving heat resistance is to mix PE and heat-resistant inorganic particles or PP to prepare battery separators, which can combine the advantages of various materials.
Completely change the base material
such as polyimide and other materials to replace the traditional PP and PE materials. Polyimide is costly but can consider the combination of polyimide and PE, or other types of polymer materials can also be considered.