How to occupy the power lithium-ion battery market with dry separators?
Previously, under the directivity of high energy density, because the microporous separator prepared by the wet method was lighter and thinner, the wet method + coating separator was considered to be more suitable for the manufacture of ternary batteries with high energy density, and the market demand for the wet method separator also followed rapidly. The rise has broken the market pattern dominated by dry-process separators in the field of lithium-ion batteries.
According to data from the Lithium Battery Research Institute (GGII), my country's lithium-ion battery separator shipments reached 2.02 billion square meters in 2018, a year-on-year increase of 39.7%. Among them, the shipment volume of wet process diaphragm was 1.31 billion square meters, up 66.4% year-on-year; the shipment volume of dry process diaphragm was 706 million square meters, up 7.8% year-on-year, and the growth rate was much lower than that of wet process.
In 2019, the new subsidy policy was launched, and the slashed slope and the increased emphasis on product safety performance forced the new energy vehicle and power lithium battery industry chain to return to market-oriented thinking. As a result, dry-process separators with low cost, excellent performance and thinning are also expected to usher in a counterattack in the market.
Gaogong Lithium Battery has learned that the current dry single-pull diaphragm used in large-scale power lithium batteries is 20μm, 18μm and 16μm are already on the way to large-scale use. In 2018, the price of dry-process single-pull films dropped by more than 40% year-on-year. This year, the average price of some low-end dry-process single-pull base films has fallen below 1 yuan/square meter (wet process diaphragms are 1.8-2 yuan/square meter).
At present, the mainstream of ternary power lithium battery adopts wet coating separator with thickness of 12+4 (12μm base film + 4μm coating). Lithium battery companies began to cut into the use of 18μm, 16μm products. The above-mentioned person said that once the 16μm products are used on a large scale, with the blessing of cost advantages, the dry-process single-pull diaphragm will erode the wet-process diaphragm market to a certain extent.
Below 20μm becomes a stepping stone for power
Dry-process separators want to counterattack the power lithium battery market. In addition to low cost, thinning and high safety are also breakthroughs that dry-process separator companies must consider.
Gaogong Lithium has learned that the reason why dry separators are less used in the ternary power lithium battery market is thickness, because thinner separators can reserve more space for the battery to accommodate active materials, thereby improving energy density. After the dry-process separator is made thin, if the strength is reduced, there will be potential safety hazards in the lithium-ion battery.
However, with the improvement of technical process, the dry-processed diaphragm is gradually transitioning to the trend of thinning. The dry diaphragm used in power lithium batteries was 32μm at first, and then gradually evolved into 25μm, 24μm, 22μm, and the mainstream model at this stage is 20μm.