Friction-enhancing core surface of battery separator roll and method thereof

Abstract

A roll of battery separator material and related methods are disclosed, the roll of battery separator material including a core including an outer surface, a separator material wound around the core, and a friction-enhancing surface on at least a portion of the outer surface of the core for preventing lateral migration of the separator material relative to the outer surface of the core.

Description

Copyright Notice

[0001] © 2020 Amtek Research LLC. Some of the disclosures in this patent document contain copyrighted material. The copyright holder reserves all other rights, except that they will not object to anyone reproducing the patent document or patent disclosure by facsimile, as it exists in the patent files or records of the Patent and Trademark Office. [Technical Field]

[0002] The present invention relates to a battery separator for use in lead-acid batteries, and more particularly to a separator roll core having a friction-enhancing surface that limits the slippage of the separator roll on the core and releases cleanly when fully deployed. [Background technology]

[0003] Valve-regulated lead-acid (VRLA) and liquid lead-acid are two distinct types of commercially available lead-acid battery designs. Both types include adjacent positive and negative electrodes separated from each other by a porous battery separator. The porous separator prevents electrical short circuits between adjacent electrodes and provides space for the electrolyte to exist. Such separators are formed from materials that are sufficiently porous to allow the electrolyte to reside within the pores of the separator material, thereby enabling the flow of ionic current between adjacent positive and negative electrodes.

[0004] The first type of lead-acid battery, VRLA, typically includes an absorbent glass mat (AGM) separator made of microglass fibers. While AGM separators offer high porosity (over 90%), low ion resistance, and uniform electrolyte distribution, they are relatively expensive. Furthermore, AGM separators have low fracture resistance. Low fracture resistance is problematic for two reasons: (1) it increases the occurrence of short circuits, and (2) the manufacturing cost is higher because the AGM sheets are fragile. Battery manufacturers may choose thicker, more expensive separators to improve fracture resistance, but they are aware that ion resistance increases with thickness.

[0005] The second type of lead-acid battery, the liquid-type battery, is characterized by the fact that only a small portion of the electrolyte is absorbed by the separator. Separators for immersion batteries typically include porous derivatives of cellulose, polyvinyl chloride, organic rubber, and polyolefin. Specifically, microporous polyethylene separators are often used because their ultrafine pore size suppresses dendritic growth, resulting in low ion resistance, high fracture resistance, excellent oxidation resistance, and flexibility. These properties facilitate the encapsulation of the battery separator into a pocket or enclosure configuration into which the positive or negative electrode can be inserted.

[0006] Recently, enhanced electrolyte batteries (EFBs) have been developed to meet the high cycle requirements of automotive applications such as "start-stop" and "micro-hybrid" vehicles. In these applications, the engine stops while the vehicle is stationary (for example, at a traffic light) and is restarted afterward. The advantage of "start-stop" vehicle designs is that they lead to reduced CO2 emissions and improved overall fuel efficiency. A major challenge for "start-stop" vehicles is that the battery must continue to supply all electrical functions while the vehicle is stopped, while simultaneously supplying enough current to restart the engine at the moment it is needed. In such cases, the battery needs to exhibit higher performance in terms of cycle and recharge capabilities compared to conventional immersion lead-acid battery designs.

[0007] Most liquid lead-acid batteries contain polyethylene separators. The term "polyethylene separator" is somewhat misleading because these microporous separators require a large amount of precipitated silica to achieve sufficient acid wettability. The volume fraction and distribution of precipitated silica within the separator generally govern its electrical properties, while the volume fraction and orientation of polyethylene within the separator generally govern its mechanical properties. The porosity of commercially available polyethylene separators typically ranges from 50% to 65%.

[0008] The main purposes of the polyolefin included in the separator are (1) to provide mechanical binding to the polymer matrix so that the separator can be surrounded at high speed, and (2) to prevent the grid wires from breaking during battery assembly or operation. Therefore, hydrophobic polyolefins are preferably those with a molecular weight that provides sufficient molecular chain entanglement to form a microporous web with high fracture resistance. The main purpose of hydrophilic silica is to improve the acid wettability of the separator web, thereby reducing the electrical resistivity of the separator. Without silica, sulfuric acid would not wet the hydrophobic web, ion transport would not occur, and consequently the battery would not function.

[0009] In the manufacture of polyethylene separators, precipitated silica is typically combined with polyolefin, process oil, and various trace components to form a separator mixture, which is extruded at high temperature through a sheet die to form an oil-filled sheet. The oil-filled sheet is calendered to the desired thickness and shape, and most of the process oil is extracted. The sheet is dried to form a microporous separator made of polyolefin, which is then slit to the appropriate width according to the battery design. The separator may be wound onto a core or roll for convenience during transportation and battery manufacturing.

[0010] When a battery (e.g., a lead-acid battery) is manufactured, a containment device releases the separator material from the roll of battery separator material, cuts the separator material, forms the separator material within the "container," inserts the battery electrodes into the containment, and seals the ends to form the electrode package. The electrode package is stacked so that the separator acts as a physical spacer and electronic insulator between the positive and negative electrodes. Then, an electrolyte is introduced into the assembled battery to facilitate ion conduction within the battery.

[0011] For proper battery assembly, it is usually necessary to carefully control the direction and speed at which separator material is supplied to the containment device to avoid malfunctions caused by incorrect supply of separator material. This requires mounting a roll that allows the separator material to be freely released from the roll and fed into the containment device. To form the roll and achieve this purpose, it is necessary to use a roll of sheet-like battery separator material wound around the outer surface of a cardboard core. The side edges of the released separator material are aligned to form a substantially horizontal surface located in the center between the outer edges of the core.

[0012] Maintaining the horizontal surface of a sheet of separator material, which is trapped between the outer edges of the core, presents challenges for at least two reasons. The first reason is that the separator material tends to slip in the direction of the core's axis as the roll is wound, transported, and unrolled. The second reason is that the embossed ribs on the separator material cause it to wobble, thereby causing axial movement of the separator material along the centerline as the ribbed layers come into contact with each other, as the roll size increases.

[0013] Figures 1-2 show rolls of separator material that can be used in battery manufacturing. Figures 3-4 show rolls of separator material that cannot be used in battery manufacturing.

[0014] Figure 1 is a perspective view of a roll 100 consisting of battery separator material 102 wound around a core 104 and attached to a portion of the encircling machine 106. Figure 2 is a side view of the roll in Figure 1. A common problem encountered when manufacturing batteries is that the separator material slips relative to the core when it is released from the roll. This slip results in lateral migration of the separator material on the core (i.e., axial movement of the core). An example of this phenomenon is shown in Figures 3 and 4. These figures show the roll 100 in a state where the separator material 102 is no longer confined between the ends of the core 104 due to migration during winding. Furthermore, if the separator material is not almost completely unfolded, the embossed ribs tend to promote axial movement of the remaining wound portion of the separator material relative to the core. This misalignment can cause misfeeding of the separator material into the encircling phase of the machine, hindering or preventing the proper operation of the machine. As a result, manufacturing may be interrupted, or separator materials, other battery materials, or battery manufacturing equipment may be damaged. Problems to be solved by the invention.

[0015] One approach to prevent migration was to bond the separator material to the core with tape or other adhesives. However, this is an unsuitable solution for many encirclement machines. Attaching the proximal end of the separator material to the core with tape or other adhesives often results in undesirable tension or recoil in the material supplied to the machine when the roll is fully released. This snagging or recoil of the separator material results in misalignment of the separator material during the encirclement process. Therefore, an effective solution to migration that does not involve such undesirable consequences is needed. Means of solving the problem.

[0016] This specification discloses friction enhancement of the core surface of a battery separator roll and related methods. In a preferred embodiment, one or more friction enhancement materials, such as sandpaper or rubber strips or sleeves, are attached to the surface of a core used to wind a roll of battery separator material. The friction enhancement material increases the frictional resistance between the core and the separator material by at least 1.75 times - for example, at least 2 times, at least 3 times, or about 2 to 3 times - thereby reducing the probability that the separator material migrates away from the core. However, the friction enhancement material allows the separator material to be released from the core without pulling or backlash (i.e., sufficient release characteristics are maintained). In some embodiments, the surface of the core itself may include a friction-enhanced surface.

Brief Description of the Drawings

[0017] To easily identify discussions of specific elements or acts, the most significant digit of a reference number refers to the figure number in which that element was first introduced. [Figure 1] Perspective view of a roll of a battery separator, which is a typical example of the prior art. [Figure 2] Side view of the roll of FIG. 1. [Figure 3] Perspective view of a roll of a battery separator material according to the prior art. Migration of the battery separator material with respect to the core around which the battery separator material is wound is shown. [Figure 4] Different perspective view of the roll according to the prior art of FIG. 3. [Figure 5] Diagram of a core of a roll of a battery separator material according to some embodiments. [Figure 6] Represents an image of the configuration of an inspection used in the experiment of Example 1.

Modes for Carrying Out the Invention

[0018] This specification discloses a friction-enhanced core surface of a battery separator roll and related methods. As used herein, the term "friction-enhanced" means that the material or surface on the core increases the frictional resistance between the core and the battery separator material while maintaining sufficient release characteristics of the core (i.e., when the roll of battery separator material is finished and separates from contact with the friction-enhanced material or surface on the roll, the battery manufacturing apparatus does not receive pulling and / or reaction), referring to the characteristics of the material or surface on the core. According to a preferred embodiment, the friction-enhanced surface can be provided by a material having friction-enhanced characteristics attached to the outer surface of the core. As used in the specification, "friction-enhanced material" includes solids, liquids, gels, pastes, and combinations thereof that can be adhered, applied, or otherwise fixed to the core to provide a friction-enhanced surface. For example, the friction-enhanced material may be in the form of a sleeve or band surrounding the outer surface of the core. Preferably, the friction-enhanced material is a strip of material applied to the outer surface of the core.

[0019] The friction-enhanced surface reduces the probability that the separator material migrates away from the core by increasing the friction between the core and the separator material compared to a core without a friction-enhanced surface. In some embodiments, one or more strips of friction-enhanced material are attached to the surface of the core used to wind the battery separator material. In certain embodiments, the strip of friction-enhanced material consists of a strip of sandpaper. In some embodiments, the surface of the core itself may include or be modified to include a friction-enhanced surface.

[0020] FIG. 5 is a perspective view of a core 500 for inclusion in a roll of separator material according to some embodiments. The core 500 has a coefficient of static friction μ b-s and a coefficient of kinetic friction μ b-kIt includes a base core 502 having an outer surface 506. Further, the core 500 includes a friction enhancing material 504 on or fixed to the outer surface 506 of the base core 502. The friction enhancing material 504 includes a friction enhancing surface 508 facing outward from the core 500. The friction enhancing surface 508 has an enhanced static friction coefficient μ b-s greater than the base static friction coefficient μ of the outer surface 506 of the base core 502 e-s , for example, having a static friction coefficient at least 1.75 times, at least 2 times, or about 2 to 3 times. The friction enhancing surface 508 also has an enhanced kinetic friction coefficient μ b-k greater than the base kinetic friction coefficient μ of the outer surface 506 of the base core 502, such as at least 1.75 times, at least 2 times, or about 2 to 3 times e-k .

[0021] The friction enhancing surface or material preferably provides a maximum kinetic friction coefficient (determined using the method of Example 1) of at least about 0.8, such as about 0.8 to about 1.2, to the separator material (on the back surface, rib side, or both). The term "maximum" should be understood as the maximum value of the kinetic friction coefficient obtained during the friction test, rather than an upper limit of the kinetic friction coefficient. Thus, for example, at least 0.8 would be the minimum value desired for the maximum value of the kinetic friction coefficient.

[0022] The friction enhancing material preferably provides an average kinetic friction coefficient of at least 0.6 - for example, about 0.6 to about 1.0 - to the separator material (on the back surface, rib side, or both).

[0023] As used herein, the term "static friction coefficient" (sometimes denoted as "μ s " or a variation thereof) refers to a constant that relates the frictional force (sometimes denoted as "F f ") (experienced by an object stationary relative to the surface) to the normal force (sometimes denoted as "F n ") (represented by an arrow in FIG. 3 and exerted on the object by the surface) (F f =sF nFor example, when the separator material is wound around the core 500, the tension and / or other forces (e.g., gravity) of the separator material exert a force inward on the core 500. On the other hand, the core 500 exerts an outward normal force on the separator material to balance the inward force exerted by the separator material. The force exerted on the separator material parallel to the outer surface 506 of the core 500 is the frictional force F. f =sF n As long as it does not exceed a certain value, the separator material remains stationary relative to the core 500.

[0024] As used herein, the term "coefficient of kinetic friction" ("μ") k (F) is a constant that relates the frictional force (actually experienced by an object moving relative to a surface) to the normal force (that the surface exerts on the object). f =kF n ). For example, the force applied to the separator material causes the separator material to slide relative to the core 500 (for example, (F f =sF n (F) On the other hand, if the separator material remains in motion relative to the core 500, the frictional force is (F f =sF n It is given by ).

[0025] In the example shown in Figure 3, the presence of the friction-enhancing material 504 increases the overall static and dynamic friction coefficients of the core 500 compared to the friction coefficient of only the outer surface 506 of the base core 502. As a result, lateral migration of the separator material relative to the core 500 is less likely to occur during winding and unwinding. Furthermore, even if lateral migration of the separator material relative to the core 500 does occur, the sliding is more likely to stop sooner than in the absence of the friction-enhancing material 504, and it may be possible to prevent the separator material from completely separating from the core 500 due to lateral migration.

[0026] The friction-enhancing material 504 has sufficient release properties so that the battery manufacturing apparatus does not experience tension and / or recoil when the roll of the battery separator material ends and it leaves contact with the friction-enhancing material 504. Preferably, the friction-enhancing material 504 does not contain adhesive on its outer surface. The friction-enhancing material 504 may be attached to the outer surface 506 with adhesive, but the adhesive does not come into contact with the battery separator material rolled onto the core 500.

[0027] The base core 502 may have a hollow cylindrical shape as illustrated in Figure 5, or it may have other shapes (e.g., a solid cylindrical shape, a planar shape, a non-circular cylindrical shape, etc.). The base core 502 may contain any variety of materials. For example, the base core 502 may contain cardboard, synthetic polymers (e.g., plastics), metal, wood, or other materials suitable for supporting the roll of separator material. In some embodiments, the friction-reinforcing material 504 may contain the same material as the base core 502. As a non-limiting example, the friction-reinforcing material 504 may be formed directly from the base core 502 itself by texturing the outer surface 506 of the base core 502. In some embodiments, the friction-reinforcing material 504 is a different material from that of the base core 502 and is fixed to the outer surface 506 of the base core 502 (e.g., using adhesive, staples, rivets, nails, or other fastening mechanisms). In some embodiments, the base core 502 may contain a friction-enhancing material itself, in which case the entire outer surface 506 may have enough friction to prevent the separator material from moving laterally without the friction-enhancing material 504.

[0028] Figure 5 shows a portion of the outer surface 506 of the base core 502 containing the friction-enhancing material 504. However, the outer surface 506 of the base core 502 may include multiple regions of the friction-enhancing material 504, or it may be completely covered by the friction-enhancing material 504. Also, Figure 5 shows a rectangular strip of friction-enhancing material 504 provided on the outer surface 506 of the base core 502. However, its outer surface 506 may include one or more pieces of friction-enhancing material 504 of various shapes other than rectangles (e.g., triangles, octagons, circles, ellipses, other polygons, irregular shapes, etc.) and sizes. Preferably, the strip or other rectangular shape of the friction-enhancing material is positioned on the outer surface 506 at an angle of about 30° to about 60°, for example, about 45°, with respect to the center line of the central roll (i.e., the direction in which the separator material is pulled when it is unfolded from the roll). However, the angle can also be about 0° (i.e., parallel to the pulling direction), as depicted in Figure 5. Furthermore, the angle can be approximately 90° (i.e., perpendicular to the direction of tension).

[0029] Problems related to winding and unwinding ribbed battery separator material can also arise with other sheet materials that have longitudinal ribs on at least one surface. Therefore, in one embodiment, a method for winding ribbed material includes providing a cylindrical core (e.g., such as a base core 502) having an outer surface having a width defined by its outer edge. A friction-reinforced surface is formed on at least a portion of the outer surface of the core, as described above. The width of the core is selected to be greater than or equal to the width of a continuous sheet of ribbed material. The ribbed material on the outer surface of the core is sufficiently aligned such that the outer edge of the core is at the same height as the outer edge of the ribbed material, or extends beyond the outer edge of the ribbed material (for example, it is preferable that the ribbed material is located in the middle between the outer edges of the core). The ribbed material is engaged with the friction-reinforced surface by frictional force. The ribbed material is wound onto the outer surface of the core under tension. The frictional engagement between the core and the first loop of the ribbed material makes it easier to maintain the alignment of the ribbed material on the roll while winding the entire roll. This facilitates the side margins of the wound roll having substantially horizontal surfaces in the center between the outer edges of the core (i.e., the outer edges of the ribbed material are coplanar with or within the boundary defined by the outer edges of the core).

[0030] In the case of battery separator materials, ribbed materials often have ribbed sides and a flat back. The flat back can be wrapped around the outer surface of the core. Alternatively, the ribbed surface may be wrapped around the outer surface of the core. In particular, ribbed materials may have ribs on at least one surface of the ribbed material that are oriented longitudinally with respect to the sheet of material.

[0031] A well-wound roll of battery separator material facilitates the battery manufacturing process. Therefore, in one embodiment, the battery manufacturing process includes providing a roll of battery separator material wound as described above, benefiting from a friction-enhanced surface on at least a portion of the core (i.e., the side margins of the wound roll have substantially horizontal surfaces in the center between the outer edges of the core). The frictional engagement between the core and the initial loop of battery separator material helps prevent lateral migration of the roll when it is unfolded and fed into battery manufacturing equipment such as a sieve. Beneficially, since the battery separator material is not fixed to the core with tape or other adhesives, when the roll is removed, the remaining portion of the battery separator material is fully unfolded and released from the core without the battery manufacturing equipment being affected by tension or recoil on the battery separator material. Thus, obstacles in the battery manufacturing process can be avoided.

[0032] Similarly, a second roll of battery separator material wound as described above, utilizing the advantage of a friction-enhanced surface on at least a portion of the core, can be supplied to the battery manufacturing apparatus, minimizing downtime in the battery manufacturing process. The end of the first roll may be secured to the beginning of the second roll with tape or by other means. [Example 1]

[0033] As shown in Figure 8, frictional interactions between various core surface materials and separator materials were tested. A corrugated cardboard core was cut, unfolded, and placed on a steel sheet as a flat rectangular surface. A 1-inch (2.54 cm) wide strip of test material was attached to cardboard at a 45° angle to the direction in which the separator material sample was pulled. The test material strip was aligned with the front of the separator material sample at the start of the test. Small pieces of double-sided tape and magnets were used at the ends to secure the test material piece in place for the test. A 4-inch x 2-inch separator material sample was attached to the underside of a weighted block and placed on top of the cardboard. This weighted block was connected to a Mark-10 Model M5-5 force gauge. The total weight of the weighted block and separator material sample combined was 414.6–414.7 grams. The test speed was approximately 8.2 mm / second (or approximately 490 mm / minute). The tests were conducted using a cardboard core alone, two types of sandpaper ("US" = 80 grit, "ESA" = 100 grit), and two types of rubber (nitrile rubber and latex rubber (the type used for rubber gloves)).

[0034] Both the ribbed and back surfaces of two types of separator materials ("STD" = standard, "LR" = low resistance) were tested. STD was an ENTEK PE separator with a GE profile, a width of 162 mm, a back web thickness of 0.25 mm, and an overall thickness of 1.3 mm. LR was an ENTEK LR separator with a GE profile, a width of 162 mm, a back web thickness of 0.25 mm, and an overall thickness of 0.8 mm. The GE profile has ribs on the sides and a flat back surface. The ribbed surface includes main ribs and secondary ribs (the difference between the back web thickness and the overall thickness is the height of the main ribs relative to the top surface of the back web).

[0035] Six tests were conducted for each combination of the test material (or core alone), separator material sample, and separator side. The maximum and average forces observed during tensile stress were recorded and used to calculate the coefficient of friction for each combination. While we do not wish to be constrained by theory, the maximum and average coefficients of friction are considered to be the maximum and average coefficients of kinetic friction, respectively. The results are shown in Table 1 below. [Table 1] Table 1 shows the force (in Newtons) applied when different battery separator materials are pulled at a constant speed onto a test surface, both the maximum and average force observed during the pulling process, and the coefficient of friction calculated based on each force value. Each value is the average of six tests.

[0036] It will be apparent to those skilled in the art that many modifications can be made to the details of the embodiments described above without departing from the fundamental principles of this disclosure. Therefore, the scope of this disclosure should be determined solely by the following claims.

Claims

1. A roll of battery separator material, The core, including the outer surface, A separator material wrapped around the core, The core includes a friction-enhancing surface provided on at least a portion of the outer surface of the core to prevent lateral migration of the separator material relative to the outer surface of the core, The friction-enhancing surface increases the frictional resistance of the battery separator material on the core by at least 1.75 times compared to the core without the friction-enhancing surface. The friction-enhancing surface includes one or more strips or sleeves of material applied to the outer surface of the core, and is separate from the outer surface of the core, and includes friction-enhancing material attached to the outer surface of the core using at least one of adhesive, rivets, nails, or fasteners. roll.

2. A roll according to claim 1, wherein the friction-enhancing material comprises one or more strips of the material to which the separator material is attached when unfolded from the roll.

3. A roll according to claim 1, wherein the friction-enhancing material includes sandpaper or a rubber material.

4. A roll according to claim 1, wherein the core includes a cardboard core or a plastic core.

5. A roll according to claim 1, wherein the static friction coefficient on the friction-enhancing surface is 2 to 3 times that of the static friction coefficient on the outer surface of the core without the friction-enhancing material.

6. A roll according to claim 1, wherein the coefficient of dynamic friction on the friction-enhancing surface is 2 to 3 times greater than the coefficient of dynamic friction on the outer surface of the core without the friction-enhancing material.

7. A roll according to claim 1, wherein the friction-enhancing surface increases the frictional resistance of the separator material on the core by 2 to 3 times compared to the core without the friction-enhancing material.

8. A roll according to claim 1, wherein the friction-enhancing surface provides the battery separator material with a maximum dynamic friction coefficient of at least 0.

8.

9. A roll according to claim 1, wherein the friction-enhancing surface provides the battery separator material with an average dynamic friction coefficient of at least 0.

6.

10. A roll according to claim 1, wherein the battery separator material comprises a polyolefin-based separator material.

11. A roll of battery separator material, The core, including the outer surface, A separator material wrapped around the core, Includes a friction-enhancing surface that completely covers the outer surface of the core to prevent lateral migration of the separator material to the outer surface of the core, The friction-enhancing surface is separate from the outer surface of the core and includes a friction-enhancing material comprising one or more strips or sleeves of material attached to the outer surface of the core using at least one of adhesive, rivets, nails, or other fasteners. The friction-enhancing surface increases the frictional resistance of the battery separator material on the core by at least 1.75 times compared to the core without the friction-enhancing surface. roll.

12. A roll according to claim 11, wherein the friction-enhancing material includes sandpaper or a rubber material.

13. Battery manufacturing process, A step of providing a roll of a battery separator comprising: a first core having an outer surface and an outer edge; a first battery separator material having an outer edge and a width less than or equal to the first core, wherein the outer edge is coplanar with the outer edge of the first core, or is aligned on the outer edge of the first core to extend beyond the outer edge; and a friction-enhancing surface comprising one or more strips or sleeve materials provided on at least a portion of the outer surface of the first core to prevent lateral migration of the outer surface of the first battery separator material relative to the outer surface of the first core, and being separate from the core and attached to the core using at least one of adhesive, rivets, nails, or other fasteners; The steps include: unfolding a portion of the first battery separator material from the roll and supplying it to a battery manufacturing apparatus while maintaining the outer edge of the remaining portion of the first battery separator material on the same plane as or inside the outer edge of the first core; A step of releasing the remaining portion of the first battery separator material from the first core by unfolding the remaining portion of the first battery separator material without being pulled on the first battery separator material and / or causing a reaction within the first battery separator material, Sharpening process.

14. The process according to claim 13, A step of providing another roll of a battery separator comprising: a second core having an outer surface and an outer edge; a second battery separator material having an outer edge and a width less than or equal to the second core, wherein the outer edge is coplanar with the outer edge of the second core, or is provided on the outer surface of the second core to extend beyond the outer edge; and a friction-enhancing surface provided on at least a portion of the outer surface of the second core to prevent lateral migration of the outer surface of the second battery separator material relative to the outer surface of the second core, while maintaining sufficient release characteristics of the outer surface of the second core; The step of unfolding the remaining portion of the second battery separator material while maintaining the outer edge of the remaining portion of the second battery separator material on the same plane as or inside the outer edge of the second core, thereby releasing the remaining portion of the second battery separator material from the second core. Sharpening process.

15. A process according to claim 14, wherein the step of supplying a portion of the second battery separator material to a battery manufacturing apparatus includes the step of continuing the supply of the battery separator material to the battery manufacturing apparatus by securing the end of the first battery separator material that is released from the first core with tape or overlapping it with the starting portion of the second battery separator material.

16. The process according to claim 13, wherein the roll includes the roll according to claim 1.

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