阅读说明：本技术 具有肋的电池隔离件及在隔离件上铸造肋的方法 (Battery separator with ribs and method of casting ribs on separator ) 是由 纳泰什·古比克里希纳帕 于 2014-09-11 设计创作，主要内容包括：具有肋的电池隔离件及在隔离件上铸造肋的方法。本公开内容提供了在基底上铸造肋的方法,所述方法包括以下行为：安装涂布机,所述涂布机包括多个喷嘴和填充到涂布机中的聚合物；将基底放置在涂布机的喷嘴下方；在熔融聚合物上施加压力以在基底上铸造多个预定形状的聚合物肋；以及将铸造有肋的基底冷却。(A battery separator having ribs and a method of casting ribs on a separator. The present disclosure provides a method of casting a rib on a substrate, the method comprising acts of: installing a coater including a plurality of nozzles and a polymer filled into the coater; placing a substrate under a nozzle of a coater; applying pressure on the molten polymer to cast a plurality of predetermined shaped polymer ribs on the substrate; and cooling the cast ribbed substrate.)

1. A method of casting ribs on a substrate, the method comprising acts of:

a. installing a coater comprising a plurality of nozzles and a polymer filled into the coater,

b. placing the substrate under the nozzle of the coater,

c. applying pressure on the molten polymer to cast a plurality of predetermined shaped polymer ribs on the substrate; and

d. cooling the substrate cast with ribs.

Technical Field

The present disclosure relates to a battery separator, and more particularly, to a battery separator including ribs and a method of laying ribs on the battery separator.

Background

All batteries require a battery separator for separating the positive and negative electrodes while allowing ionic conduction. The thickness of the separator base web or back web, as well as the overall thickness (i.e., the thickness of the separator with ribs or glass mat(s) or both) depends on the type of separator, the type of application, and the expected battery life.

Most polyethylene spacers are manufactured in a variety of different rib designs disposed on one or both sides of the backweb. The thickness, width and angle of the ribs vary from application to application and brand to brand. Most automotive partitions are ribbed with 0.7mm and are typically placed 1cm apart and all along the length of the partition. These ribs help create additional space between the electrodes to provide additional electrolyte volume needed for cell performance. In applications such as stationary and traction applications, the rib thickness can be as high as 1.2mm and in many designs it is present on both sides of the dorsal web. This is done in view of the life expectancy of the battery, the need for higher amounts of electrolyte between the electrodes.

The ribs are typically provided on the polyethylene separator by an in-line process in which an extruded polyethylene separator web is passed between a pair of grooved calender rolls which produce the ribs on the polyethylene as it passes through the calender. For each change in rib design and size, a new specially designed pair of calender rolls must be used.

Similarly, ribs are provided on one or both sides of the PVC separator depending on the end use of the cell. Typically such ribs are about 1.0mm thick, and in some applications the final thickness of the spacer may be as high as 4 mm. In sintered PVC separators, ribs are provided by scraping off the sintered resin by grooved rollers. The grooves actually form a continuous rib on the spacer. In the case of extruded or calendered PVC separators, the process of forming the ribs is similar to polyethylene, with the calendering rolls stamping (impression) the desired rib design. There are also spacers that have fewer ribs but use corrugation as a process to increase the overall thickness of the spacer. Also in this case, the total weight of the separator increases due to an increase in the area of the separator consumed in the corrugating process.

Therefore, the weight of the ribs in the spacer is considerable. The cost of manufacturing new ribs is also expensive because it requires replacement of the calender rolls with new ones and the electrolyte discharge is also higher due to the additional volume of these rib materials. It is well known in battery design that the separator should have the lowest amount of acid to be removed. The higher the acid bleed, the lower the cell performance.

Most types of separators made by wet-laid techniques, such as SPG separator resin impregnated cellulose and other composite separators rely heavily on the use of fiberglass sheets (very thick backwebs), rely very little on extruded ribs or combinations of these. Most of these separators require fiberglass plates or ribs or both, depending on the end application and also due to compositional limitations (e.g., oxidative degradation, larger pore sizes, etc.).

Most wet laid separators vary in thickness by varying the thickness of the backing web and the thickness of the fiberglass sheet. As the thickness of the backweb or fiberglass sheet increases, the cost of the spacer increases significantly. In applications where a backing mesh, fiberglass panel thickness, and both fiberglass panel and ribs are used in combination, the cost of the spacer is greatly increased. The increased thickness achieved by these techniques not only increases cost, but also degrades battery performance due to higher acid bleed, and the greater mass of material between the electrodes means higher resistance of the separator, which in turn affects battery performance.

From a prior art search, it can be observed that no spacer or spacer manufacturing technique, other than the use of ribs or fiberglass plates, increases the overall thickness of the spacer. All existing spacer production techniques may be limited to the use of continuous ribs or fiberglass plates or both to increase the overall thickness of the spacer. The purpose of the glass fibre sheet or ribs is only to provide additional electrolyte, but the cost increases considerably. Any attempt to reduce the rib length is limited by production techniques known to date or by alternative methods not considered.

Disclosure of Invention

Accordingly, the present disclosure provides a method of casting a rib on a substrate, the method comprising the acts of: installing a coater including a plurality of nozzles and a molten polymer filled into the coater; placing a substrate under a nozzle of a coater; applying pressure on the molten polymer to cast a plurality of predetermined shaped polymer ribs on the substrate; and cooling the substrate cast with the ribs, and also providing a predetermined shaped substrate comprising a plurality of predetermined shaped ribs in a predetermined manner.

Drawings

Fig. 1 shows a spacer with straight triangular ribs.

Fig. 2 shows a spacer with straight arcuate ribs.

Figure 3 shows a spacer with vertical interrupted ribs.

Fig. 4 shows a spacer with horizontal interrupted ribs.

Fig. 5 shows a spacer with dots.

Fig. 6 shows a spacer having a diagonal interrupted rib.

Fig. 7 shows a spacer with intersecting discontinuities and dots.

Figure 8 shows a spacer with vertical dash-like (dash) ribs and dots.

Fig. 9 shows a spacer with horizontal dashes and dots.

Figure 10 shows a spacer with serrated ribs.

Figure 11 shows a spacer with interrupted serrated ribs.

Figure 12 shows a spacer with two sided triangular ribs.

The figures depict embodiments of the present disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.

Detailed Description

The present disclosure relates particularly to battery separators. More particularly, the disclosure relates to battery separators including ribs and methods of laying ribs on battery separators.

The primary embodiment of the present disclosure provides a method of casting ribs on a substrate, the method comprising the acts of: installing a coater including a plurality of nozzles and a molten polymer filled into the coater; placing a substrate under a nozzle of a coater; applying pressure on the molten polymer to cast a plurality of predetermined shaped polymer ribs on the substrate; and cooling the cast ribbed substrate.

In one embodiment of the present disclosure, the substrate is in the form of a roll or sheet prior to casting the ribs on the surface of the substrate, and wherein the substrate with the cast ribs is cut to the desired dimensions to form the battery separator.

In one embodiment of the present disclosure, the size of the ribs is varied by adjusting the applied pressure, the viscosity of the polymer, the size of the nozzle opening, and the feed of the substrate.

In one embodiment of the present disclosure, the ribs are applied in the following configuration: continuous longitudinal ribs, discontinuous longitudinal ribs, continuous diagonal ribs, discontinuous diagonal ribs, discrete dots, and discrete beads having different densities.

In one embodiment of the present disclosure, the coater is a hot melt adhesive coater.

In one embodiment of the present disclosure, the polymer used to cast the ribs is melted in a coater, and the polymer is selected from the group consisting of: polyester, polyethylene, polypropylene, and ethylene vinyl acetate.

In one embodiment of the present disclosure, the spacer is additionally attached to the fiberglass panel by pressing.

The present disclosure also relates to a predetermined shaped substrate comprising a plurality of predetermined shaped ribs in a predetermined manner.

In one embodiment of the present disclosure, the substrate is in the form of a roll or sheet and cut to the desired size to form the battery separator prior to casting the ribs on the surface of the substrate.

In one embodiment of the present disclosure, the ribs are in the following configuration: continuous longitudinal ribs, discontinuous longitudinal ribs, continuous diagonal ribs, discontinuous diagonal ribs, discrete dots, and discrete beads having different densities.

In one embodiment of the present disclosure, the process of casting ribs on the spacer backweb is accomplished by applying polymer dots or beads by a polymer coater that injects polymer melt at high pressure and the size of the polymer dots or beads is controlled by varying the pressure, viscosity and nozzle size and also the velocity of the backweb.

In one embodiment of the present disclosure, the most suitable polymer coater is a hot melt adhesive coater having a polymer melt tank, a polymer melt pump and a set of nozzles to dispense the polymer melt, as well as the required polymer delivery hoses and process controls.

In one embodiment of the present disclosure, the polymer used in the dots or beads herein has the following characteristics: for example, electrolyte resistance, does not melt at the operating temperature of the battery and is also resistant to electrochemical oxidation within the cell. The polymer is selected from: polyester, polyethylene, polypropylene, ethylene vinyl acetate, and the polymer used is designed or modified to flow to the spacer backweb in the coater at the desired level of adhesion.

In one embodiment of the present disclosure, the spacer applied or spotted by the above process is optionally attached to the fiberglass board by: it is passed through a continuous layer of fiberglass board and is only pressed properly to adhere, but does not allow the dots or beads to spread or form smudges. By this process, the fiberglass sheet can be adhered to the backing web of the separator without the need for an additional layer of adhesive.

In one embodiment of the present disclosure, the orientation of the dots or beads can be changed by incorporating an oscillating mechanism into the polymer dispenser. The beads are formed at an oblique angle to the length of the spacer as the dispenser is moved on the horizontal axis. The angle is controlled by varying the rate at which the polymer dispenser oscillates.

The above process can be employed in any known spacer manufacturing process technology to extend the advantages of the new spacer design.

By using multiple polymer dispensers, beads or dots can be simultaneously or selectively laid on one or both sides of the separator.

In one embodiment of the invention, the size of the polymer dots or beads can be easily adjusted by the flow rate of the polymer, the on-off time of the valve in the dispenser of the nozzle. By varying the frequency of the valve opening time, the length of the beads can be varied from a very small point of about 1mm to a continuous line. The distance between the dots or beads can be easily adjusted by changing the spacing between the nozzles or by closing alternative nozzles.

The battery separator and the method of casting ribs on the battery separator are illustrated using the following steps, first, a polymer coater is installed just after the separator backweb is formed. For example, in the wet-laid separator technology, just before the separator is wound on the pope spool and in the polyethylene separator, just after the oil is drawn off but before the separator is wound on the spool. The spacer backweb in the form of a roll or sheet without ribs then passes under a polymer coater (with nozzles positioned as needed to achieve spacing between dots). For example 25 mm. The polymers used in the coating machine are polymers suitable for specific battery chemistries, such as polyester-based hot melts for lead-acid batteries and polyamides or atactic polypropylene (atactic polypropylene) types for alkaline battery chemistries. The spot or bead size is adjusted by changing the valve on-off timer. The nozzle is oscillated to change the angle of the dot or bead. The spot or bead is cooled by air until it hardens. Optionally, the glass fiber board web is lightly pressed to attach the glass fiber board just prior to cooling of the polymer. The spacer is then cut to size.

Example 1

This embodiment shows an arrangement where a ribbed spacer is manufactured, where the ribs are in the form of discrete dots. This dotted design provides the lowest cost per square meter with the lowest resistance to ion flow within the cell in the battery, thereby reducing the total internal resistance of the battery. The following table shows experiments performed at four settings from "a" to "D". The binder used: advantra PHP9250 manufactured by H B Fullers.

TABLE 1

The results of the above table show that we can reduce the spot thickness and weight when we reduce the "open" time.

Example 2

This experiment shows the setup for casting a continuous rib and varying the thickness of the rib by varying the speed of the substrate.

In this example, composite separators of the applicant company known under the trade name Hi-Sep were used as substrates.

A 0.5mm thick spacer backweb was cast with continuous lengths of ribs to cast ribs 1.0mm to 2.30mm wide and 0.48mm to 1.94mm high with each rib spaced 1 inch apart using a Nordson coater with a "Sure bead" gun named Alta blue melt tank. The thickness of the ribs was varied by changing the conveyor speed from 2MPM to 11 MPM. As the conveyor speed increases, the adhesive consumption per millimeter decreases significantly. The results are shown below. The polymer used was a hot melt manufactured by H B Fullers under the trade name advatra 9250.

TABLE 2

Example 3

This example shows the use of a specific mix of hot melts to achieve a higher melting point for tropical climates:

a high temperature grade hot melt was prepared using a pre-melt mixing tank by using the following recipe:

TABLE 3

Components	By weight%
		Vestoplast 408 from Evonik	98
Finawax S from Fine Organics	2
		Total of	100

The molten and mixed polymer melt was then cast into ribs on the same Nordson coater and then compared to ribs cast with HB fullerens 9250. The results are compared as follows:

TABLE 4

The results in the table above show that the adhesive made with the Vestoplast 408 polymer has a higher melting temperature making it more suitable for use in tropical climates.

Example 4

In this example, a composite separator is used, known by the applicant company under the trade name Hi-Sep.

The same Nordson brand polymer coater as used in the above example was used to spot a 0.5mm thick spacer backweb to cast 2mm wide and 1mm high ribs with 1 inch spacing between each rib. Instead of ribs, beads or dots 2mm wide, 1mm thick and 15mm apart from each other in the length direction and 25mm apart in the width direction were laid in the same equipment, the difference in weight and separator performance in terms of resistance being reported in the following table. The polymer used was a hot melt manufactured by H B Fullers under the trade name advatra 9250.

TABLE 5

As is clear from the above table, the rib weight per square meter of the separator is reduced by a factor of 3, resulting in a great cost saving and a significant reduction in the electrical resistance of the separator. If the above is repeated with a foamed polymer of the same chemical composition, the weight is further reduced, leading to further cost reduction.

Advantageous effects

The present disclosure provides a battery separator that reduces the cost of the product and also improves its performance.

The present disclosure provides a battery separator that can be combined with all types of separator technologies.

The polymers used in the present disclosure are resistant to electrolytes, electrochemical oxidation, and temperature.

The method of making a battery separator according to the present disclosure is also useful in capacitor and supercapacitor applications.

Further, the present disclosure provides a battery separator that can be any size shape and size.

Furthermore, the battery separator of the present disclosure may be optionally connected with a glass fiber sheet without additional adhesives and processes.

The invention also provides the following technical scheme:

note 1. a method of casting ribs on a substrate, the method comprising acts of:

a. installing a coater comprising a plurality of nozzles and a polymer filled into the coater,

b. placing the substrate under the nozzle of the coater,

c. applying pressure on the molten polymer to cast a plurality of predetermined shaped polymer ribs on the substrate; and

d. cooling the substrate cast with ribs.

Note 2. the method according to note 1, wherein the substrate is in the form of a roll or sheet before casting ribs on the surface of the substrate, and wherein the cast ribbed substrate is cut to a desired size to form a battery separator.

Appendix 3. the method according to appendix 1, wherein the dimensions of the ribs are varied by adjusting the applied pressure, the viscosity of the polymer, the dimensions of the nozzle opening and the feed of the substrate.

Note 4. the method according to note 1, wherein the ribs are applied in the following configuration: continuous longitudinal ribs, discontinuous longitudinal ribs, continuous diagonal ribs, discontinuous diagonal ribs, discrete dots, and discrete beads having different densities.

Appendix 5. the method of appendix 1, wherein the coating machine is a hot melt adhesive coating machine.

Appendix 6. the method according to appendix 1, wherein the polymer for casting the ribs is melted in the coater and the polymer is selected from: polyester, polyethylene, polypropylene, ethylene vinyl acetate.

Note 7. the method according to note 1, wherein the spacer is additionally attached to the glass fiber sheet by pressing.

Note 8 a predetermined-shaped substrate including a plurality of ribs having a predetermined shape in a predetermined manner.

Appendix 9. the substrate according to appendix 8, wherein the substrate is in the form of a roll or sheet and cut to a desired size to form a battery separator before casting ribs on a surface of the substrate.

Note 10 the base according to note 8, wherein the ribs are of the following configuration: continuous longitudinal ribs, discontinuous longitudinal ribs, continuous diagonal ribs, discontinuous diagonal ribs, discrete or discrete dots, and discrete beads or a combination of several or all of these having different densities.

Appendix 11. the method according to appendix 1, wherein the ribs or beads are cast in the form of a sinusoid by an oscillating gun assembly.