Johnson Screen Filter for Lithium-Ion Battery Slurry Filtration
In recent years, as a new energy source, lithium ion battery has attracted more and more attention and application due to its high voltage, high specific energy, long cycle life and environmental protection.
However, the production requirements of lithium battery are high, its cost is higher than that of lead-acid battery and NiMH battery, and the finished battery has a certain proportion of self discharge.
There are some impurities in the production of lithium battery anode and cathode slurry, and the iron impurities in the slurry will cause the self discharge of the battery.
When the single iron at the negative electrode accumulates to a certain extent, the hard edge of the deposited iron tip will pierce the diaphragm and cause micro short circuit, which further leads to self discharge.
The existence of impurities will also affect the consistency of the battery pack. Only the lithium battery pack with good consistency can be grouped to the greatest extent and show its superior electrochemical performance.
How to improve the purity of the slurry is the bottleneck of the consistency of the lithium-ion battery pack.
In the production process of extrusion coating for lithium-ion battery, when the existing filter is used to filter the slurry, bubbles are easily generated, which leads to metal leakage of lithium-ion battery and increases the safety risk of lithium-ion battery.
At the same time, due to the large particles in the raw materials of the slurry and the agglomeration of the slurry, the filter will be blocked, which will seriously affect the life of the filter, and the weight fluctuation of the film caused by the filter blockage, which will seriously affect the quality of the film.
Although increasing the pore of filter screen will improve the filter life, but the efficiency of particle filtration will be reduced, the unfiltered particles will produce scratches when extruding the film and reduce the film quality.
At the same time, the existing filter has low filtration efficiency and great influence on production efficiency. It not only seriously affects the quality of extruded coating products and the safety of lithium battery, but also seriously affects the production efficiency of extruded coating, which restricts the progress of lithium battery technology.
Our wedge wire filter element perfectly solves this problem.
Johnson screen (wedge wire screen) has special v-wire structure, continuous slotting structure, with only two points of contact between impurities and filter element, not easy to block, easy to clean.
Wedge Wire candle Filter Element For Lithium Battery Slurry Filter
Wedge wire screen candle slurry filter is a new type of filter product. The rotating shaft is equipped with a magnet rod.
In the process of continuous rotation, particle impurities, slurry agglomerates and iron impurities in slurry are filtered at one time to improve the filter efficiency.
The position of the feed port is set lower than the position of the discharge port, so that the way of low in and high out reduces the introduction of external bubbles in the slurry transportation process, thus improving the coating (film/coating) quality, reducing the generation of unfiltered particles, and reducing the safety risk of the battery.
The particle impurities and slurry agglomerates on the wedge wire filter pipe are continuously removed through the rotary coordination of the wedge-shaped filter element and the scraper.
The filter failure caused by the clogging of the filter element is avoided, and the service life of the filter is improved.
The scraper can be set to multiple, which can be set according to the requirements of filtering and the height of the wedge wire filter element.
Generally, at least two symmetrical scrapers are arranged in a filter element, and the section shape of the scraper is set as a triangle, because the effect of scraping the inner wall of the wedge wire screen sieve filter element is the best.
The filter element is set with wedge-shaped structure. The wedge-shaped structure of the filter element and the scraper rotate and cooperate to continuously remove the particle impurities and slurry agglomerates on the filter element, so as to avoid the failure of the filter caused by the blockage of the filter element.
During operation, the material enters into the filter from the feed port, passes through the Johnson screen filter element, and then exits from the discharge port.
In the process of continuous feeding, the drive motor with rotating shaft, magnet bar and scraper keeps rotating in the wedge wire filter element, and the continuously stirred magnet bar plays the role of removing iron impurities in the slurry.
At the same time, the scraper rotating at a constant speed around the rotating shaft keeps scraping the inner wall of the wedge wire filter element to remove the particle impurities on the inner wall of the filter element and avoid the blockage of the filter element.
Therefore, on the one hand, such movement can fully filter the particles, slurry agglomerates and iron impurities in the slurry, on the other hand, it can continuously remove the slurry on the inner wall of the filter element to prevent the blockage of the filter element.
The fully filtered slurry enters the extrusion coating system through the discharge port. In this process, the output pressure of the filter is monitored in real time by the pressure sensor.
The isolated particle impurities and iron impurities are discharged continuously through the discharge port and the pressure regulating valve installed on the connecting pipe.
In this process, the continuous discharge flow is controlled by the accurate pressure regulation of the pressure regulating valve to ensure the overflow The chamber pressure of the filter is stable and the slag is discharged continuously.
Johnson screen candle slurry filter is not only suitable for slurry filtration of lithium-ion batteries, but also for slurry filtration of lithium-metal batteries, sodium ion batteries, nickel cadmium batteries, etc.