Battery Separators: How Can the Plastics Industry Meet the Challenges?

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Battery Separators: How Can the Plastics Industry Meet the Challenges?

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xysoom

Posted 24 April 2023 - 05:48 AM

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Battery Separators: How Can the Plastics Industry Meet the Challenges?

In recent years, there have been intensive efforts to develop advanced battery separators for rechargeable lithium-ion batteries for different applications such as:Get more news about Elastomer Separators,you can vist our website!
In these developments, the separator is a critical component of the batteries. This is because; it provides a physical barrier between the positive and negative electrodes. Doing so, it prevents electrical short circuits. In addition, the separator must be porous to allow for the effective transport of the lithium ions in the battery.

The performance of the lithium-ion batteries is greatly affected by the materials and structure of the separator.

Despite the advances that have been made in the development of separator materials, there are still several challenges that currently exist. These challenges are primarily due to new and emerging applications of Li-ion batteries. Among the existing challenges of the separator, the main ones are:Let's begin by understanding the general structure of a lithium-ion battery and the position of the separator in the battery (see figure below) before we discuss above-mentioned challenges in detail and how the plastics industry can help meet these challenges:
The wettability of the separator toward non-aqueous electrolytes can significantly impact the performance of a lithium-ion battery. The wettability issue is a continuing concern. This is because larger batteries are being developed for applications such as electric vehicles.
The wettability concern becomes more critical for large capacity electrodes. These are developed for vehicle applications where the entrance area is limited and the transport distance increases for the electrolyte.

Currently, most commercial separators for lithium-ion batteries are typically porous polyolefin films, both polyethylene and polypropylene. These polymer separators are generally not compatible with some conventional electrolytes that include solvents of high dielectric constants, such as:This is due to the low surface energies of the polyolefins. Also, this incompatibility can lead to incomplete filling or extended manufacturing times. In addition, the distribution of the electrolyte in the cell is uneven and this leads to poor long-term stability of the battery as well as uneven current distributions.
2. Thermal Stability of Separator

Another current continuing need for battery separators is an increased thermal stability compared to current polyolefin materials. A growing demand for large format cells that have more energy than usual small format cells is driving a need for the development of separators that have an increased thermal stability compared to polyolefin materials. These larger format cells are being used in both electric vehicle and power grid applications.

This is because the larger batteries have a greater potential to have thermal events. These events can lead to rapid large temperature increases and ultimately fires and even explosions.

3. Thinner Separators

As batteries that possess higher power and energy densities continue to be developed, there is a need to include more active electrode material. This means that there is less space in the batteries for the separator and the separator must be thinner than current products. However, at the same time, it is desirable to retain similar mechanical properties with the thinner separators.

This is necessary because it is the mechanical properties of the separators that are one of the factors that are responsible for providing safety to the battery. The puncture strength of the separator is particularly important in this regard and it is well established that the puncture strength is inversely related to the thickness for a particular type of separator.