Details
| Tensile Strength MD (Kgf/cm2) | 1533 |
| Puncture Strength (g) | 526 |
| Product Width (mm) | |
| Air Permeability (Sec/100ml) | 217.8 |
| Elongation at Break TD (%) | 0.6 |
| Porosity (%) | 40 |
| Product Thickness (µm) | 17 |
| Tensile Strength TD (Kgf/cm2) | 1282 |
| Elongation at Break MD (%) | 0.7 |
| Area Density (g/m2) | 12.07 |
The PE base film is 12µm thick, the ceramic coating is ~2µm thick, and PVDF is coated on the surface of the ceramic particles, with a thickness of ~2µm.
CCS and PCS are coated on the same side; this separator has a single-sided CCS+PCS coating.
The ceramic coating improves the thermal shrinkage performance of the separator, enhancing battery safety. The PVDF coating helps bond the positive electrode to the separator, improving the battery interface and increasing battery hardness and cycle performance.
The melting point of the PE separator is ~140℃.
Overview:
The separator is a crucial component of lithium-ion batteries. It's a microporous membrane used to separate the positive and negative electrodes, and is a high-molecular functional material with a nanoscale microporous structure. Its main function is to prevent short circuits caused by electrode contact while allowing electrolyte ions to pass through. Its performance determines the battery's interface structure, internal resistance, etc., directly affecting the battery's capacity, cycle life, and safety performance.
Basic Introduction:
The separator accounts for approximately one-third of the total cost of a lithium-ion battery. As a core material ensuring the safe and stable operation of lithium-ion batteries, domestic manufacturers currently rely almost entirely on imports from Japan, the United States, and South Korea. The progress of domestic production of this high-tech and high-profit material will be a major breakthrough area for reducing lithium-ion battery costs. The main challenges lie in composite materials, thickness, strength, and pore size. Currently, commercially available lithium-ion battery separator products are mostly microporous membranes made of polyolefin materials, primarily high-molecular-weight polyethylene and polypropylene. Products include polyethylene (PE) single-layer membranes, polypropylene (PP) single-layer membranes, and multilayer microporous membranes composed of PP and PE. Polyolefin materials possess advantages such as high strength, good resistance to acid and alkali corrosion, water resistance, chemical resistance, good biocompatibility, and non-toxicity, and their industrial preparation is relatively mature. Lithium-ion battery separators that are still in the research stage or have not yet been widely applied include PET/cellulose nonwoven fabrics, polyvinylidene fluoride (PVDF) porous membranes, polyimide (PI) electrospun porous membranes, and various PE, PVDF, PP, and PI modified membranes.
Type and Model Classification:
Currently, the main separator materials used are PP, PE, and PP/PE/PP three-layer separators, with a porosity generally between 28-40%.
Coated separator (12um + aluminum oxide/PVDF coating); Coated separator (9um + aluminum oxide/PVDF coating); Coated separator (7um + aluminum oxide/PVDF coating); Ceramic-coated separator (12um + aluminum oxide coating); Ceramic-coated separator (9um + aluminum oxide coating); Ceramic-coated separator (7um + aluminum oxide coating); Separator (12um); Separator (9um); Separator (7um)
Application:
During battery assembly and charge/discharge cycles, the separator material itself needs to have a certain mechanical strength. The mechanical strength of the separator can be measured by tensile strength and puncture resistance. Tensile uniformity is also a crucial performance parameter. Since separators smaller than 9µm require ceramic coating, the tensile uniformity in the TD direction must meet certain requirements to satisfy the coating process. The physical structure of the separator has a significant impact on the mechanical safety performance of the battery cell. Energy cell evaluations show that high porosity worsens impact throughput, while small-pore separators can improve impact but cannot achieve 100% throughput. Nail test results show that separators with poorer thermal stability have lower throughput, and thinner separators also have lower throughput. This is because, in the event of an internal short circuit (local high-rate discharge), low porosity and small-pore separators can limit the local high-rate current, preventing further propagation of the failure point and thus improving the test throughput. As a safety barrier separating the positive and negative electrodes, the separator's thermal stability, mechanical strength, and thickness also play important roles.
Assembly Method/Process Flow:
The main material for lithium-ion battery separators is porous polyolefin. There are two main preparation methods: wet and dry. The wet method is also known as phase separation or thermally induced phase separation (TIPS); the dry method, also called melt-stretched pore-forming method or melt-stretched pore-forming method (MSCS), aims to improve the porosity and strength of the separator. The classification, processes, and characteristics of separators are shown in the table below. Additionally, PET/cellulose nonwoven fabrics are manufactured using nonwoven fabric technology, polyvinylidene fluoride (PVDF) porous membranes also use phase separation methods, and polyimide (PI) and polyamide (PAI) use electrospinning and casting phase separation processes.
Lithium-ion Battery Separator Technical Requirements:
The performance of the lithium-ion battery separator determines the battery's interface structure, internal resistance, etc., directly affecting the battery's capacity, cycle life, and safety performance. Therefore, the technical requirements for lithium-ion battery separators are as follows:
1) Insulation performance: It must be an insulator that conducts electrons.
2) Minimal repulsion from the electrolyte, possessing good electrolyte wetting properties.
3) High ionic conductivity, i.e., low resistance to the movement of dielectric ions.
4) Effective prevention of the migration of particles, colloids, or other soluble substances between the positive and negative electrodes.
5) High mechanical strength to ensure no tearing or deformation during processing.
6) Dimensional stability: Minimal dimensional change below the melting point temperature to prevent short circuits between the positive and negative electrodes.
7) Chemical stability and electrochemical inertness: Sufficiently stable against the electrolyte, potential impurities, electrode reactants, and electrode reaction products, without dissolving or degrading.
8) High uniformity in thickness and pore size.
Overview:
The separator is an important part of lithium-ion batteries. It is a microporous membrane used to separate the positive and negative pole pieces. It is a nano-scale microporous structure. Polymer functional materials. Its main function is to prevent the two poles from contacting and short-circuiting while allowing electrolyte ions to pass. Its performance determines the interface structure and internal resistance of the battery
Overview:
The separator is an important part of lithium-ion batteries. It is a microporous membrane used to separate the positive and negative pole pieces. It is a nano-scale microporous structure. Polymer functional materials. Its main function is to prevent the two poles from contacting and short-circuiting while allowing electrolyte ions to pass. Its performance determines the interface structure and internal resistance of the battery
Overview:
The separator is an important part of lithium-ion batteries. It is a microporous membrane used to separate the positive and negative pole pieces. It is a nano-scale microporous structure. Polymer functional materials. Its main function is to prevent the two poles from contacting and short-circuiting while allowing electrolyte ions to pass. Its performance determines the interface structure and internal resistance of the battery