Key Takeaway: In short, a separator is a porous plastic film. Yang explained that lithium-ion batteries are mainly composed of a positive electrode, a negative electrode, an electrolyte, a membrane, and a casing. The separator in a lithium-ion battery prevents short circuits between the positive and negative electrodes and provides a channel for lithium-ion transport during charging and discharging. The performance of the separator determines the capacity, internal resistance, cycle life, storage, and safety of the lithium-ion battery. The separator is the most technologically advanced component of a lithium-ion battery, thus accounting for about one-third of the battery cost. He said that with the strong national support for the development of electric vehicles, my country's demand for power lithium-ion battery materials will experience explosive growth in the next few years. By 2012, the demand for lithium-ion battery films for electric vehicles will increase tenfold, reaching approximately 400 million square meters.
Currently, my country's lithium-ion battery separator market is facing a severe supply shortage, with most of the market dominated by American and Japanese products, resulting in persistently high prices. After more than a decade of research and development, our separator production has been industrialized, breaking the foreign dominance in the Chinese market. This was stated by Yang Shuting, director of Henan Xinxiang Green New Energy Materials Co., Ltd., at the 2010 (5th) International Forum on Power Lithium-ion Battery Technology and Industrial Development held last week.
Yang Shuting explained that the company has already achieved a production capacity of 60 million square meters of diaphragm, but the products are still in short supply. Therefore, the company has decided to add a production line with an annual output of 100 million square meters, and the project is under construction.
The high technological content of membranes stems from the difficulty in perforating them. Currently, the main types of membranes worldwide include single-layer polypropylene (PP) nanoporous membranes, single-layer polyethylene (PE) nanoporous membranes, and PP/PE/PP three-layer composite nanoporous membranes. Grein's technological breakthrough lies in its single-layer PP microporous membrane. Our company employs a dry biaxial stretching process, which involves adding an organic crystal nucleating agent to polypropylene. Utilizing the density difference between different phases of polypropylene, the crystalline morphology transforms into micropores during horizontal and vertical stretching. Membrane thicknesses can reach 15 to 60 micrometers, making them particularly suitable for power lithium-ion batteries.
In short, a separator is a thin layer of porous plastic. Yang explained that lithium-ion batteries mainly consist of a positive electrode, a negative electrode, an electrolyte, a membrane, and a casing. The separator prevents short circuits between the positive and negative electrodes and provides a channel for lithium-ion transport during charging and discharging. The performance of the separator determines the capacity, internal resistance, cycle life, storage, and safety of the lithium-ion battery. The separator is the most technologically advanced component of a lithium-ion battery, accounting for about one-third of the battery cost. He said that with strong national support for the development of electric vehicles, my country's demand for power lithium-ion battery materials will explode in the coming years. By 2012, the demand for lithium-ion battery films from electric vehicles will increase tenfold, reaching approximately 400 million square meters annually. However, due to the high technological content of separators, domestic production has not yet achieved this.
