The development trend of the two ends of domestic power cell diaphragm technology

Lithium-ion battery industry is in the ascendant in China. Under the encouragement of state policy, existing production capacity expansion and potential production capacity development have multiplied year by year. As the most profitable diaphragm in the inner layer components of lithium-ion batteries, it has taken the lead in development.

At present, the main performance requirements of lithium battery diaphragm are: thickness uniformity, mechanical properties (including tensile strength and anti-puncture strength), breathability, physical and chemical properties(including wettability, chemical stability, thermal stability, safety) and other four performance indicators.

The development of lithium battery diaphragm technology is promoted with the changes of lithium ion battery application. The outstanding feature is that the lithium battery is getting smaller and the lithium battery is getting bigger and bigger.

From the "small" point of view

Mainly reflected in portable consumer electronics lithium batteries, such as mobile phones, digital cameras, electronic dictionaries, etc., beautiful and miniaturized high energy density requirements for lithium battery design, promoting the diaphragm for such lithium battery applications should be made thinner. Because the meaning of high energy density is to accommodate more electrode materials in a small volume, under the condition that the positive and negative electrode materials have been set, the transcendence of the diaphragm performance becomes inevitable, which requires that in the case of a thinner diaphragm, Maintain the original battery capacity and cycle life.

From the "big" point of view

It is mainly reflected in the lithium-powered batteries used in electric bicycles and electric vehicles. It is not difficult to see through the domestic exposure of electric vehicle spontaneous combustion events. Safety performance is currently the bottleneck that restricts the power lithium batteries. The main reasons for this are in these three aspects:

1, safety is the core of the physical and chemical properties of lithium ion battery diaphragm, any of the other three performance defects may lead to safety performance instability;

2, the larger the capacity of the power lithium battery monomer core itself, the smaller the number of cores in series. This objectively requires that the power lithium battery adopts a larger capacity core. The larger the capacity, the performance of the core. Indicators need more delicate processes to ensure;

3, due to the consistency of the series core and the combination of technology will bring security risks, this especially requires the manufacture of lithium battery diaphragm more sophisticated.

The excellent performance of lithium cells and lithium batteries can not be fully expected to achieve this goal in a piece of diaphragm. The full match between the positive and negative poles and the electrolyte components can achieve this goal. The lithium battery has more technical problems. However, the importance of diaphragm technology as the most valuable lithium battery technology is self-evident.

The page contains the contents of the machine translation.