Carbon-containing and / or carbon-coated lead-acid battery separator and method for retarding dendritic crystal formation thereof

Abstract

A lead acid battery separator includes a porous membrane wherein within the porous membrane, a conductive element and / or a conductive or semiconductive nucleation additive is contained. According to the present invention, inside the battery separator, numerous nucleation sites are provided to provide starting points for crystal formation at numerous locations, thereby dispersing the total amount of lead sulfate into a large number of smaller crystals, rather than a small number of larger crystals; thus, these smaller crystals are more readily returned to the electrolyte during the charge cycle of the lead acid battery, thereby hindering the slowed growth of dendrites within the separator of the lead acid battery, increasing the charge acceptance of the battery, and / or improving the cycle performance of the battery.

Description

[0001] This application is a divisional application, with the original priority date being September 8, 2017; the original international application date being September 7, 2018; the original international application number being PCT / US2018 / 049847; the date of entry into the Chinese national phase being April 28, 2020, and the Chinese application number being 201880070489.6; the original invention name being “Improved Carbon-Containing Lead-Acid Battery Separator”. Technical Field

[0002] According to at least selected embodiments, the present disclosure or invention is directed to new or improved separators for lead-acid batteries, such as flooded lead-acid batteries, particularly enhanced flooded lead-acid batteries (EFBs), and various other lead-acid batteries, such as gel and absorbed glass mat (AGM) batteries. According to at least selected embodiments, the present disclosure or invention is directed to new or improved separators, battery separators, carbon-containing battery separators, conductive carbon-containing battery separators, EFB separators, membranes, scrims (gauze), mats, batteries, galvanic cells, systems, methods thereof, vehicles using them, methods of making them, uses thereof, and combinations thereof. Additionally, disclosed herein are methods, systems, and battery separators for extending battery life, reducing battery failure, reducing water loss, improving oxidation stability, increasing, maintaining, and / or reducing float current, improving end-of-charge current (EOC), reducing current and / or voltage required to charge and / or fully charge a deep cycle battery, minimizing internal resistance, reducing resistance, increasing wettability, reducing electrolyte wetting time, shortening battery formation time, reducing antimony poisoning, reducing acid stratification, improving acid diffusion, and / or improving uniformity, and combinations thereof, in lead-acid batteries. According to at least particular embodiments, the present disclosure or invention is directed to an improved separator for a lead-acid battery, wherein the separator comprises rubber, latex, and / or improved performance enhancing additives and / or coatings. According to at least particular embodiments, the disclosed separators are useful for deep cycle applications, such as in mobile machines such as golf carts (sometimes referred to as golf carts), inverters, and renewable energy systems and / or alternative energy systems such as solar power generation systems and wind power generation systems. The disclosed separators are also useful in battery systems where operation at deep cycles and / or partial states of charge is part of the battery application. In certain other embodiments, the disclosed separators can be used in battery systems where additives and / or alloys (antimony is an important example) are added to the battery to improve battery life and / or performance and / or increase the battery's ability to operate at deep cycles and / or partial states of charge. According to at least selected embodiments, the present disclosure or invention can solve current problems or needs, and / or can provide improved separators and / or batteries that overcome current problems or difficulties, such as by providing batteries that slow dendrite formation, have improved charge acceptance, and / or have improved cycling performance. Background Art

[0003] The battery separator is used to separate the positive electrode (or positive plate) and the negative electrode (or negative plate) of the battery to prevent electrical short circuits. Such battery separators are usually porous so that ions can pass between the positive electrode (or positive plate) and the negative electrode (or negative plate). In lead-acid batteries such as automotive batteries and / or industrial batteries and / or deep cycle batteries, the battery separator is usually a porous polyethylene separator; in some cases, such a separator may include a back mesh and a plurality of ribs on one or both sides of the back mesh. See Besenhard, JO, ed., Handbook of Battery Materials, Chapter 9, pp. 245-292, Wiley-VCH Verlag GmbH, Weinheim, Germany (1999). Some separators for automotive batteries are made in continuous lengths and rolled up, then folded and sealed along the edges to form a bag or envelope to hold the battery electrodes. Specific separators for industrial (or traction or deep cycle storage) batteries are cut to approximately the same size as the electrode plates (sheets or leaves).

[0004] The electrodes in lead-acid batteries are usually made of lead alloys with relatively high antimony content. Batteries operating at a partial state of charge (PSoC) are prone to self-acid stratification. In this case, more acid is enriched in the electrolyte at the bottom of the battery, while more water is enriched in the electrolyte at the top of the battery. Lead becomes soluble in water and enters the solution. However, lead precipitates in the acid and forms solid crystals. Therefore, acid stratification tends to lead to the formation of lead sulfate (PbSO4) crystals that form dendrites. Even without acid stratification, the acid will be depleted during the discharge process and lead will enter the solution and then precipitate into crystals when the acid is recovered in the charging cycle.

[0005] When these crystals accumulate to a large enough size, the dendrites can tear or burn a hole in the separator and form a conductive bridge connecting the negative electrode to the positive electrode, resulting in a short circuit. This can hinder voltage discharge, charge acceptance, or even lead to catastrophic failure and render the battery inoperable. All of this can impair the performance and life of the battery.

[0006] There remains a need for improved separators to provide improved cycle life, reduced acid stratification and / or slowed dendrite formation for at least certain applications or batteries. More particularly, there remains a need for improved separators and improved batteries (such as those operating at a partially charged state) containing improved separators that provide extended battery life, reduced battery failure, improved oxidation stability, increased, maintained and / or reduced float current, improved end of charge current (EOC), reduced current and / or voltage required for deep cycle battery charging and / or full charging, minimized internal resistance increase, reduced resistance, reduced antimony poisoning, reduced acid stratification, improved acid diffusion and / or improved uniformity in lead acid batteries. Summary of the invention

[0007] The details of one or more embodiments are set forth in the following description. Other features, objects, and advantages will be apparent from the description and claims. According to at least selected embodiments, the present disclosure or invention may address the above-mentioned problems or needs. According to at least specific objects, aspects, or embodiments, the present disclosure or invention may provide an improved separator and / or battery that overcomes the above-mentioned problems, for example, by providing a battery with reduced acid stratification, slowed dendrite formation, and / or improved cycling performance.

[0008] According to at least selected embodiments, the present disclosure or invention can solve the above problems or needs. According to at least specific purposes, aspects or embodiments, the present disclosure or invention can provide improved separators and / or batteries that overcome the above problems, such as by providing batteries that slow dendrite formation, have improved charge acceptance and / or have improved cycling performance.

[0009] According to at least selected embodiments, the present disclosure or invention is directed to new or improved separators, battery separators, battery separators containing carbon, battery separators containing conductive carbon, EFB separators, galvanic cells, batteries, systems and / or methods of making and / or using such new separators, galvanic cells and / or batteries. According to at least specific embodiments, the present disclosure or invention is directed to new or improved battery separators for flat plate batteries, tubular batteries, flooded lead acid batteries, enhanced flooded lead acid batteries (EFB), deep cycle batteries, gel batteries, absorbed glass mat (AGM) batteries, inverter batteries, solar or wind power batteries, vehicle batteries, start lighting ignition (SLI) vehicle batteries, idle start stop (ISS) vehicle batteries, car batteries, truck batteries, motorcycle batteries, all terrain vehicle batteries, forklift batteries, golf cart batteries, hybrid vehicle batteries, electric vehicle batteries, electric rickshaw batteries, electric bicycle batteries, and / or improved methods of making and / or using such improved separators, galvanic cells, batteries, systems and / or the like. Additionally, disclosed herein are methods, systems, and battery separators for improving battery performance and life, reducing battery failure, reducing acid stratification, slowing sulfation and dendrite formation, improving oxidation stability, increasing, maintaining, and / or reducing float current, improving charge termination current, reducing current and / or voltage required for deep cycle battery charging and / or full charging, reducing internal resistance, reducing antimony poisoning, increasing wettability, improving acid diffusion, improving uniformity, and / or improving cycling performance in lead acid batteries. According to at least particular embodiments, the present disclosure or invention is directed to an improved separator, wherein the new separator includes reduced sulfation and dendrite formation and increased charge acceptance.

[0010] Selected embodiments of the present invention provide a lead-acid battery separator having a porous membrane, a base cloth (gauze) and / or a pad and a nucleating additive. The porous membrane is selected from polyolefins, polyethylene, polypropylene, rubber, polyvinyl chloride, phenolic resin, cellulose, synthetic wood pulp, glass fiber, synthetic fiber, natural rubber, synthetic rubber, latex, bisphenol formaldehyde and combinations thereof. If the separator is polyethylene, it can be ultra-high molecular weight polyethylene (UHMWPE).

[0011] The nucleating additive may be conductive. The nucleating additive may further be in the form of carbon or barium sulfate. The carbon may be in the form of conductive carbon, graphite, artificial graphite, activated carbon, carbon paper, acetylene black, carbon black, high surface area carbon black, graphene, high surface area graphene, keitjen black, carbon fiber, carbon filament, carbon nanotube, open cell carbon foam, carbon mat, carbon felt, carbon buckminster fullerene (buckyball), aqueous carbon suspension, and combinations thereof. The nucleating additive may be in the porous membrane, base fabric (gauze) and / or pad or on one or more surfaces of the porous membrane, base fabric (gauze) and / or pad.

[0012] In other words, the nucleating additive and / or the conductive carbon may be added inside the porous membrane, base cloth (gauze) and / or pad.

[0013] Nucleating additives and / or conductive carbon may also be coated on one or more surfaces of the porous membrane, base cloth (gauze) and / or mat.

[0014] The nucleating additive can be applied to the porous membrane by any of the following methods: roller coating, chemical vapor deposition, coextrusion, controlled scorching of the surface, controlled scorching of the surface by plasma exposure, controlled scorching of the surface by ultraviolet irradiation, toner printing, inkjet printing, flexographic printing, lithographic printing, slurry coating, spraying aqueous carbon suspension, impregnation, and combinations thereof.

[0015] In selected embodiments, the lead-acid battery separator may be an AGM separator.

[0016] In other exemplary embodiments, the porous membrane, base cloth (gauze) and / or pad may contain a particulate filler and a processing plasticizer. Carbon may be further located on the surface of the separator together with a certain amount of particulate filler. The particulate filler may be any of the following: dry finely divided silica, precipitated silica, amorphous silica, alumina, talc, or a combination thereof.

[0017] In certain embodiments, the processing plasticizer can be any of the following: processing oil, paraffinic mineral oil, mineral oil, or a combination thereof.

[0018] In selected embodiments, the porous membrane, base cloth (gauze) and / or pad may be configured with a performance enhancing additive, which may be any of the following: a nonionic surfactant, an ionic surfactant, an anionic surfactant, a wetting agent, a colorant, an antistatic additive, a UV protection additive, an antioxidant, or a combination thereof.

[0019] In certain exemplary embodiments, the porous membrane may be provided with any of the following: solid ribs, discrete intermittent ribs, continuous ribs, discontinuous ribs, angled ribs, linear ribs, longitudinal ribs extending substantially along the machine direction of the porous membrane, transverse ribs extending substantially along the cross-machine direction of the porous membrane, cross-cutting ribs extending substantially along the cross-machine direction of the separator, serrated protrusions or serrated ribs, stacked protrusions or stacked ribs, curved or sinusoidal ribs, ribs arranged in a solid or intermittent zigzag manner, grooves, grooves, textured areas, protrusions, depressions, porous, non-porous, micro-ribs, crossed micro-ribs, and combinations thereof.

[0020] Another exemplary embodiment of the present invention provides a lead-acid battery having an electrolyte, a positive electrode, a negative electrode, a separator disposed therebetween, and a nucleating additive. The nucleating additive may preferably be stable in the electrolyte and dispersible in the electrolyte. The nucleating additive may be at least semi-conductive. In some embodiments, the separator may be configured with a nucleating additive. In addition, the nucleating additive may be any one of the following: carbon, conductive carbon, graphite, artificial graphite, activated carbon, carbon paper, acetylene black, carbon black, high surface area carbon black, graphene, high surface area graphene, keitjen black, carbon fiber, carbon filament, carbon nanotube, open-cell carbon foam, carbon mat, carbon felt, carbon buckminster fullerene (buckyball), aqueous carbon suspension, barium sulfate, and combinations thereof.

[0021] In certain embodiments, the nucleating additive may be on the surface of the separator and may be adjacent to the negative electrode. Additionally, the nucleating additive may be within the separator.

[0022] In selected embodiments of the present invention, the nucleating additive can be applied to the surface of the separator by any of the following methods: roller coating, chemical vapor deposition, coextrusion, controlled burning of the surface, controlled burning of the surface by plasma exposure, controlled burning of the surface by ultraviolet irradiation, toner printing, inkjet printing, flexographic printing, lithographic printing, slurry coating, spraying of aqueous carbon suspension, and combinations thereof. In addition, the nucleating additive can be added to any of the following: adhesive paper, base cloth (gauze), and combinations thereof.

[0023] In some exemplary embodiments, the separator may be any one of the following: polyolefin, UHMWPE, polyethylene, polypropylene, rubber, polyvinyl chloride, phenolic resin, cellulose, synthetic wood pulp, glass fiber, synthetic fiber, natural rubber, synthetic rubber, latex, bisphenol formaldehyde and combinations thereof. Other separators may be AGM separators.

[0024] The lead-acid battery may be any of the following: a planar battery, a flooded lead-acid battery, an enhanced flooded lead-acid battery, a deep cycle battery, an absorbed glass mat battery, a tubular battery, an inverter battery, a vehicle battery, an SLI battery, an ISS battery, a car battery, a truck battery, a motorcycle battery, an all-terrain vehicle battery, a forklift battery, a golf cart battery, a hybrid vehicle battery, an electric vehicle battery, an electric rickshaw battery, an electric tricycle battery, and an electric bicycle battery. The battery may operate in a partially charged state in motion or at rest.

[0025] In another exemplary embodiment of the present invention, a vehicle may be configured with a battery, a separator, and a nucleating additive. In some embodiments, the separator may be configured with a nucleating additive in or on its surface. In addition, the nucleating additive may be any one of the following: carbon, conductive carbon, graphite, artificial graphite, activated carbon, carbon paper, acetylene black, carbon black, high surface area carbon black, graphene, high surface area graphene, keitjen black, carbon fiber, carbon filament, carbon nanotube, open cell carbon foam, carbon mat, carbon felt, carbon buckminster fullerene (buckyball), aqueous carbon suspension, barium sulfate, and combinations thereof.

[0026] In selected embodiments of the present invention, the nucleating additive can be applied to the surface of the separator by any of the following methods: roller coating, chemical vapor deposition, coextrusion, controlled burning of the surface, controlled burning of the surface by plasma exposure, controlled burning of the surface by ultraviolet irradiation, toner printing, inkjet printing, flexographic printing, lithographic printing, slurry coating, spraying of aqueous carbon suspension, and combinations thereof. In addition, the nucleating additive can be added to any of the following: adhesive paper, base cloth (gauze), and combinations thereof.

[0027] In selected embodiments, the battery may operate in a partially charged state. In other embodiments, the vehicle may be any of a car, a truck, a motorcycle, an all-terrain vehicle, a forklift, a golf cart, a hybrid vehicle, an electric vehicle, a rickshaw, an electric tricycle, and an electric bicycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1A A typical lead-acid battery is shown.

[0029] Figure 1B A typical single primary cell of a typical lead-acid battery is depicted.

[0030] Figure 1C Shown as in Figure 1B Acid stratification in a typical lead-acid battery cell as generally depicted in FIG.

[0031] Figure 2A An exemplary battery separator is depicted between the positive and negative electrodes as found in a typical lead-acid battery.

[0032] Figure 2B Depicted are an exemplary battery separator and expanded negative active material (NAM) as found in a typical lead-acid battery.

[0033] Figure 2C An exemplary embodiment of a battery separator of the present invention is depicted disposed between a positive electrode and a negative electrode as would be found in a typical lead-acid battery; the negative electrode is shown together with an expanded NAM.

[0034] Figure 2D-1 and Figure 2D-2 An exemplary embodiment of the rib profile of an exemplary embodiment of the separator of the present invention is shown.

[0035] Figures 3A-3C is a SEM image of graphite.

[0036] Figure 3D is a SEM image of artificial graphite.

[0037] Figure 3E is a SEM image of acetylene black.

[0038] Figures 4A-4C is a SEM image of lead sulfate growth on a lead electrode in the presence of a carbon coated separator.

[0039] Figures 5A-5C is a SEM image of lead sulfate growth on a carbon-containing separator in an extrusion mix.

[0040] Figures 6A-6C is a SEM image of lead sulfate growth on a lead electrode in the presence of a carbon-containing separator in an extrusion mix.

[0041] Fig.6D It is the schematic diagram of the NH appearance in which the parent case appears in the specification and the sub-case is moved to the attached drawings, and it has 18 positive electrode ribs and no negative electrode ribs.

[0042] Figures 7A-7C Basic physical properties of exemplary battery separators of the present disclosure are depicted.

[0043] Fig.7D It is a schematic diagram about improving cycle life and discharge termination voltage, in which the parent case appears in the specification and the branch case is moved to the attached drawings.

[0044] Figures 8A-8E A general depiction of various rib patterns for an exemplary battery separator of the present disclosure is shown.

[0045] Fig. 9A and 9B Depicted are the charging dynamics of a test cell using a separator having an acetylene black coating compared to a control cell having a commercially available separator. DETAILED DESCRIPTION

[0046] According to at least selected embodiments, the present disclosure or invention can solve the above problems or needs. According to at least specific purposes, aspects or embodiments, the present disclosure or invention can provide improved separators, battery separators, carbon-containing battery separators, conductive carbon-containing battery separators, EFB separators and / or batteries, which overcome the above problems, for example, by providing batteries with reduced dendrite formation, improved charge acceptance and / or improved cycling performance.

[0047] like Figure 1A , an exemplary lead-acid battery 50 having a positive terminal 51 and a negative terminal 53 is shown. Within the battery 50 is a set of alternating positive plates or positive electrodes 52 and negative plates or negative electrodes 54, with an exemplary separator 100 disposed therebetween. The positive electrodes 52 and negative electrodes 54 and the separator 100 are substantially immersed in an aqueous electrolyte solution 56. The electrolyte may be, for example, a solution of sulfuric acid (H2SO4) and water (H2O). The electrolyte solution may have a specific gravity in the range of about 1.215 to 1.300, for example, about 1.28. The positive electrode 52 is in electrical communication with the positive terminal 51, and the negative electrode 54 is in contact with the negative terminal 53.

[0048] refer to Figure 1B , which shows a typical primary cell of a typical lead-acid battery. Figure 1C Description, it should be noted that Figures 1A-1C It is not drawn to scale. It should also be noted that in a typical lead-acid battery, the positive electrode 52 is in intimate contact with the separator 100, and similarly, the negative electrode 54 is also in intimate contact with the separator 100. The separator is to separate the positive electrode 52 and the negative electrode 54 and prevent the battery from shorting.

[0049] Figure 1C is a schematic diagram of acid stratification as seen in a particular lead-acid battery. Sulfuric acid, being heavier than water, tends to settle to the bottom of the electrolyte, leaving the bottom of the electrolyte with a higher than optimum specific gravity, while the top of the electrolyte, which is mostly water, has a lower than optimum specific gravity. This acid stratification affects both the performance and life of the battery, since only the lower portion of the electrodes is in contact with the sulfuric acid. Acid stratification can be mitigated by overcharging the battery or keeping it charged at or near 100% capacity. During overcharging, gas bubbles tend to form on the electrodes and rise to the surface, providing mixing action to the electrolyte. Under continuous conditions where the battery is in a partial state of charge (PSoC), this overcharging action never occurs, and the extent of electrolyte stratification becomes greater.

[0050] The reaction (positive half reaction) at the lead dioxide (PbO2) positive (+) electrode 52 provides electrons and leaves the positive electrode. This positive half reaction during discharge at the lead dioxide (PbO2) positive (+) electrode 52 produces lead sulfate (PbSO4) and water (H2O) and is shown in the following equation 1:

[0051]

[0052] in:

[0053] ·PbO2 is the solid lead dioxide positive (+) electrode 52;

[0054] · It is water-based;

[0055] ·4H + It is water-based;

[0056] 2e - In a solid lead dioxide (PbO2) positive (+) electrode 52;

[0057] PbSO4 is a solid precipitate in the aqueous electrolyte 56; and

[0058] H2O is a liquid.

[0059] When charging the battery 50, the positive electrode half reaction is reversible.

[0060] The negative electrode half reaction (negative electrode half reaction) at the lead (Pb) negative (-) electrode 54 provides positive ions and leaves the negative electrode. The negative electrode half reaction during discharge produces lead sulfate (PbSO4) and negative ions (e - ) and is shown in Equation 2 below:

[0061]

[0062] in:

[0063] · Pb is a solid lead negative (-) electrode 54;

[0064] · It is water-based;

[0065] PbSO4 is a solid precipitate in the aqueous electrolyte 56; and

[0066] 2e - In the lead (Pb) negative (-) electrode 54;

[0067] The negative electrode half reaction is reversible when charging the battery 50.

[0068] Together, these half reactions give the overall chemical reaction for a lead-acid battery, as shown in Equation 3 below:

[0069]

[0070] in:

[0071] · Pb is a solid negative (-) electrode 54;

[0072] ·PbO2 is the solid positive (+) electrode 52;

[0073] H2SO4 is a liquid in the aqueous electrolyte 56;

[0074] PbSO4 is a solid precipitate in the aqueous electrolyte 56; and

[0075] H 2 O is the liquid in the aqueous electrolyte 56 .

[0076] When charging the battery 50, the overall chemical reaction is reversible.

[0077] For each of the above reactions, discharge proceeds from left to right and charge proceeds from right to left.

[0078] From the overall reaction, the discharge of the battery produces lead sulfate (PbSO4) and water (H2O). The production of water during discharge results in acid deficiency (i.e., the sulfuric acid in the electrolyte is consumed), which further exacerbates the acid stratification discussed above. In addition, lead (Pb) in the electrode plates goes into solution in the aqueous environment, which makes more lead available to form lead sulfate. Since the reaction is reversible during charging, charging and / or overcharging the battery can return some of the lead sulfate to its component parts [i.e., lead (Pb), lead dioxide (PbO2), and sulfuric acid (H2SO4)]. However, lead is also precipitated in the sulfuric acid, so some of the lead sulfate does not return to its component parts, but is left behind as solid lead sulfate crystals.

[0079] Deep cycle batteries, such as those used in golf carts (also known as golf carts), forklifts, electric rickshaws, electric bicycles, idle start-stop (ISS) vehicles, etc., operate in a partially charged state almost all the time. With the possible exception of ISS batteries, such batteries are discharged for use for 8-12 hours or more before they are recharged. In addition, operators of these batteries may not overcharge them before returning them to service. ISS batteries undergo discharge cycles and short intermittent charge cycles, and generally rarely reach a full charge or are overcharged. These batteries and other batteries are susceptible to acid stratification, acid starvation, or both. As a result, these batteries (or regions within the batteries) are subject to periods where the electrolyte has a high water concentration. These batteries (or regions within the batteries) are also subject to periods where the electrolyte has a higher acid concentration. As a result, the lead in the electrodes has the opportunity to go into solution in the electrolyte and then precipitate as lead sulfate crystals. Over time and over many discharge and charge cycles, the lead sulfate crystals accumulate on themselves to form dendrites. This is called sulfation. As these dendrites grow over time, they can short-circuit the battery or battery cell. This can result in complete battery failure, or at least poor performance and shortened battery life.

[0080] The inventors hypothesize that when the battery is charged, smaller lead sulfate crystals are more likely to return to solution than larger crystals. It is believed that providing nucleation sites gives the crystals a starting point for formation. In addition, numerous nucleation sites can provide numerous locations for the formation of crystals, thereby dispersing the total amount of lead sulfate into a large number of smaller crystals rather than a smaller number of larger crystals. Subsequently, during the charging cycle of the battery, these smaller crystals will more easily return to the solution, thereby hindering the growth of dendrites. The inventors have identified various nucleation additives for separators, such as carbon and barium sulfate (BaSO4), as exemplary means of providing these nucleation sites. These additives will be discussed herein. In addition to providing nucleation sites, carbon can also improve the battery's charge acceptance and increase the battery's capacity.

[0081] Another benefit of carbon is improved charge acceptance. One hypothesis proposed by the inventors is that the highly conductive carbon particles provide an electrical conduction path for the active material, thereby improving the utilization of the active material. Another hypothesis of the inventors is that carbon increases the capacity of the separator and thus increases the capacity of the entire battery system.

[0082] Physical Description

[0083] Exemplary separators may be provided with a mesh of porous film, such as a microporous film having pores less than about 5 μm, preferably less than about 1 μm, a mesoporous film, or a macroporous film having pores greater than about 1 μm. The porous film may preferably have a pore size of submicron up to 100 μm and between about 0.1 μm to about 10 μm in a particular embodiment. In a particular embodiment, the porosity of the separator film described herein may be greater than about 50% to about 60%, and certain other preferred embodiments may have a porosity greater than about 65%. In a particular selected embodiment, the porous film may be flat or have ribs extending from its surface.

[0084] rib

[0085] Particular objectives of the present invention include maximizing the area of ​​intimate contact between the porous membrane and the negative electrode active material as a means of improving dynamic charge acceptance, minimizing the effects of NAM expansion (e.g., acid starvation), while also taking advantage of any motion the cell may be subject to, to maximize acid mixing to reduce the effects of acid stratification, both of which are problems exhibited by cells operating in a partially charged state.

[0086] The inventors have discovered that one way to minimize the effects of NAM expansion is to maximize the elasticity of the separator, such as reducing the likelihood that the NAM will deflect the porous backing mesh into the PAM. One particular way to increase the elasticity of the separator is to increase the thickness of the porous membrane backing mesh. However, this also increases the resistance of the separator (to name just one of the disadvantages of thicker backing meshes), which negatively affects the performance of the battery. The inventors have discovered that the effect of increasing the contact points between the separator and the positive electrode is to stiffen the backing mesh between the contact points. Increasing the number of ribs to achieve this goal also increases the number of contact areas between the separator and the positive electrode. It is believed that minimizing the contact area can reduce the resistance of the separator and open up more electrode surface area to the electrolyte for the electrochemical reactions that provide battery function. It is also believed that the reduced contact area reduces the opportunity for dendrites to form on the separator and cause electrical shorts. The problem of dendrite formation is discussed below. A further object is to maximize electrolyte or acid mixing for batteries used in motion to minimize the effects of acid stratification. In addition, solid ribs are not conducive to acid mixing for the purpose of reducing acid stratification.

[0087] The inventors have discovered that, as a selected exemplary preferred embodiment, the separator may be provided with a resilient means to resist or mitigate the deflection of the back screen under the forces and pressures generated by NAM expansion (which causes acid deficiency) by maximizing the number of contact points while minimizing the contact area between the separator and the adjacent electrode. The inventors have discovered that another selected exemplary embodiment may provide a separator with an acid mixing device, which is used to reduce, mitigate or reverse the effects of acid stratification by maximizing the number of discrete contact points between the separator and the adjacent electrode. Another selected exemplary embodiment may provide a separator with a dendrite mitigation device to reduce or mitigate the growth of lead sulfate (PbSO4) dendrites. The inventors have determined that such resilient means, acid mixing means and dendrite mitigation means can be solved, achieved or at least partially solved and / or achieved through the design of the rib structure. Therefore, the selected embodiments described herein rely on the rib structure to balance these parameters to achieve the intended purpose, provide resilient means, acid mixing means and dendrite mitigation means and / or at least partially solve and / or achieve these parameters and / or the desired balance of resilient means, acid mixing means and / or dendrite mitigation means.

[0088] Figure 2A An exemplary battery separator is depicted between the positive and negative electrodes as found in a typical lead-acid battery.

[0089] Figure 2B Depicted are an exemplary battery separator and expanded negative active material (NAM) as found in a typical lead-acid battery.

[0090] Figure 2CDepicted is an exemplary embodiment of a battery separator of the present invention disposed between a positive electrode and a negative electrode as would be found in a typical lead-acid battery; the negative electrode is shown with an expanded NAM.

[0091] The ribs 104, 106 can be uniform groups, alternating groups, or a mixture or combination of the following: solid, discrete discontinuous ribs, continuous, discontinuous, angled, linear, longitudinal ribs extending substantially along the machine direction MD of the separator (i.e., extending from the top to the bottom of the separator in the battery), transverse ribs extending substantially along the cross-machine direction CMD of the separator, cross-cutting ribs extending substantially along the cross-machine direction CMD of the separator (i.e., along the transverse direction of the separator in the battery, perpendicular to MD), cross-ribs extending substantially along the cross-machine direction of the separator, discrete teeth or toothed ribs, serrated protrusions, serrated ribs, stacked protrusions or stacked ribs, curved or sinusoidal, arranged in a solid or discontinuous zigzag manner, grooves, grooves, textured areas, protrusions, depressions, porous, non-porous, micro-ribs or cross-micro-ribs and / or the like and their combinations. Furthermore, any set of ribs 104, 106 may extend from or into the positive side, the negative side, or both.

[0092] Reference Figure 2D-1 and Figure 2D-2 , the exemplary separator is provided with positive ribs 104 substantially aligned along the machine direction MD of the separator, which are used to contact the positive electrode in the exemplary battery. The separator is further provided with negative ribs 106 substantially aligned along the machine direction of the separator and substantially parallel to the positive ribs. The negative ribs are used to contact the negative electrode in the exemplary battery. Although in this illustrated example, the negative ribs are substantially aligned along the machine direction of the separator, they can alternatively be substantially aligned across the machine direction, which is generally referred to as negative cross ribs.

[0093] Continue to refer Figure 2D-1 and Figure 2D-2 , selected embodiments of the separator of the present invention are provided with a row of positive ribs. The positive ribs are provided with a bottom 104a that can extend the length of the separator in the machine direction. Then, spaced teeth, discontinuous peaks or other protrusions 104b can extend from the surface of that bottom so that the teeth 104b protrude from the surface of the porous membrane backing net below. In addition, the bottom can be wider than the teeth themselves. The positive ribs extend substantially parallel to each other at a typical spacing of about 2.5 mm to about 6.0 mm (typical spacing is about 3.5 mm). The height of the positive ribs (teeth plus bottom) measured from the surface of the porous membrane backing net can be from about 10 μm to about 2.0 mm, with a typical height of about 0.5 mm. Exemplary rib teeth of adjacent ribs can be substantially in line with each other. However, as Figure 2D-1 and Figure 2D-2As shown, exemplary teeth can be offset from one rib to an adjacent rib, completely or partially out of phase with adjacent ribs. As shown, the teeth are completely out of phase from one rib to an adjacent rib. The positive rib teeth can be spaced apart in the machine direction of the separator at a spacing of about 3.0 mm to about 6.0 mm, with a typical spacing of about 4.5 mm.

[0094] like Figure 2D-1 and Figure 2D-2 As shown, the negative electrode ribs are depicted as being substantially parallel to the machine direction of the separator. However, they may also be substantially parallel to the cross-machine direction. The depicted exemplary negative electrode ribs are shown as solid and substantially straight. However, they may also or may be as Figure 2D-1 and Figure 2D-2 The positive ribs shown in are toothed in a substantially similar manner. The negative ribs may be spaced at a spacing of about 10 μm to about 10.0 mm, preferably between about 700 μm and about 800 μm, and more preferably at a nominal spacing of about 740 μm. The height of the negative ribs measured from the back web surface may be about 10 μm to about 2.0 mm.

[0095] It should be noted that the positive electrode ribs may also or may be arranged in the exemplary battery so that they contact the negative electrode. Likewise, the negative electrode ribs may also or may be arranged in the exemplary battery so that they contact the positive electrode.

[0096] Table 1 below lists in detail the 162mm×162mm(262cm 2 ) of four separators (one exemplary inventive separator and three control separators). As shown in the table, the exemplary inventive separator has 43 toothed ribs evenly spaced across the entire width of the separator in the cross-machine direction. The teeth of the positive electrode ribs on the exemplary inventive separator contact 262 cm on the positive electrode. 2 The details of the control separators are further detailed in Table 1. It is noted that control separators #1, #2 and #3 are typical commercially available separators commonly used in current flooded lead-acid batteries and currently available in the market.

[0097] Table 1

[0098] Partition Rib [(configuration) code] Contact area (% of total area) Inventing the partition 43 (toothed rib) 3.8％ Comparison #1 22(Solid rib) 4.8％ Comparison #2 18(Solid rib) 3.9％ Comparison #3 11(Solid rib) 2.9％

[0099] As mentioned above, the inventors have found that maximizing the number of contact points while minimizing the contact area has achieved the purpose of improving the elasticity of the separator while keeping the resistance controllable. In addition, the design with teeth helps promote acid mixing by utilizing any movement that the battery may undergo. The teeth of the separator ribs can be spaced from the nearest adjacent teeth by about 2.5mm to about 6.0mm. The inventors have found that the preferred, non-restrictive distance between the adjacent teeth is about 4.2mm. In addition, the teeth completely out of phase from the adjacent row offset help promote acid mixing. The inventors have also found that the bottom helps to make the back web become hard enough to provide elasticity for the NAM expansion.

[0100] It is noted that although the exemplary inventive ribs are shown and described as positive ribs, they may be disposed on the negative side of a separator, and the negative ribs shown and described may be disposed on the positive side of a separator.

[0101] The positive electrode ribs or negative electrode ribs can also be any form or combination of the following: solid ribs, discrete intermittent ribs, continuous ribs, discontinuous ribs, angled ribs, linear ribs, longitudinal ribs extending substantially along the machine direction of the porous membrane, transverse ribs extending substantially along the cross-machine direction of the porous membrane, cross-cutting ribs extending substantially along the cross-machine direction of the separator, discrete teeth, toothed ribs, serrated protrusions, serrated ribs, stacked protrusions, stacked ribs, curved ribs, sinusoidal ribs, arranged in a continuous zigzag serrated manner, arranged in an intermittent discontinuous zigzag serrated manner, grooves, grooves, textured areas, protrusions, depressions, pillars, micro-pillars, porous, non-porous, micro-ribs, crossed micro-ribs and combinations thereof.

[0102] The positive or negative ribs may additionally be of any form or combination defined by an angle that is neither parallel nor orthogonal to the edge of the separator. Furthermore, this angle may vary across the tooth or row of ribs. An angled rib pattern may be a possible preferred RipTide TM Acid mixing rib configuration, which can contribute to reduced or eliminated acid stratification in a particular battery. Moreover, the angle can be defined relative to the machine direction of the porous membrane, and the angle can be between about greater than zero degrees (0°) and about less than one hundred and eighty degrees (180°), and between about greater than one hundred and eighty degrees (180°) and about less than three hundred and sixty degrees (360°).

[0103] The ribs may extend uniformly from lateral edge to lateral edge across the entire width of the partition. This is referred to as a universal profile. Alternatively, the partition may have side panels adjacent to the lateral edges in which smaller ribs are disposed. These smaller ribs may be more closely spaced and smaller than the major ribs. For example, the smaller ribs may be 25% to 50% of the height of the major ribs. The side panels may alternatively be flat. The side panels may assist in sealing one edge of the partition to the other edge of the partition as is done when packaging the partition, as will be discussed below.

[0104] In selected exemplary embodiments, at least a portion of the negative electrode ribs may preferably have a height of about 5% to about 100% of the height of the positive electrode ribs. In some exemplary embodiments, the height of the negative electrode ribs may be about 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 95% or 100% of the height of the positive electrode ribs. In other exemplary embodiments, the height of the negative electrode ribs may be no greater than about 100%, 95%, 90%, 85%, 80%, 75%, 70%, 65%, 60%, 55%, 50%, 45%, 40%, 35%, 30%, 25%, 20%, 15%, 10% or 5% of the height of the positive electrode ribs.

[0105] In some selected embodiments, at least a portion of the porous membrane may have a negative electrode rib that is longitudinal or transverse or cross ribs. The negative electrode rib may be parallel to the top edge of the separator, or may be arranged at an angle thereto. For example, the negative electrode rib may be oriented about 0 °, 5 °, 15 °, 25 °, 30 °, 45 °, 60 °, 70 °, 80 ° or 90 ° relative to the top edge. The cross rib may be oriented about 0 ° to about 30 °, about 30 ° to about 45 °, about 45 ° to about 60 °, about 30 ° to about 60 °, about 30 ° to about 90 °, or about 60 ° to about 90 ° relative to the top edge.

[0106] Specific exemplary embodiments may have a bottom. If present, it may have an average bottom height from about 5 μm to about 200 μm. For example, the average bottom height may be greater than or equal to about 5 μm, 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 100 μm, or 200 μm. In addition, if present, it may have an average bottom width of about 0.0 μm to about 50 μm wider than the tooth width. For example, the average bottom width may be greater than or equal to about 0.0 μm, 5 μm, 10 μm, 20 μm, 30 μm, 40 μm, or 50 μm wider than the tooth width.

[0107] Specific exemplary embodiments may have teeth or toothed ribs. If present, they may have an average tip length from about 50 μm to about 1.0 mm. For example, the average tip length may be greater than or equal to about 50 μm, 100 μm, 200 μm, 300 μm, 400 μm, 500 μm, 600 μm, 700 μm, 800 μm, 900 μm, or 1.0 mm. Alternatively, it may not be greater than or equal to 1.0 mm, 900 μm, 800 μm, 700 μm, 600 μm, 500 μm, 400 μm, 300 μm, 200 μm, 100 μm, or 50 μm.

[0108] At least a portion of the teeth or toothed ribs may have an average tooth bottom length from about 50 μm to about 1.0 mm. For example, the average tooth bottom length may be about 50 μm, 100 μm, 200 μm, 300 μm, 400 μm, 500 μm, 600 μm, 700 μm, 800 μm, 900 μm, or 1.0 mm. Alternatively, it may be not greater than or equal to about 1.0 mm, 900 μm, 800 μm, 700 μm, 600 μm, 500 μm, 400 μm, 300 μm, 200 μm, 100 μm, or 50 μm.

[0109] At least a portion of the teeth or toothed ribs may have an average height (bottom height plus tooth height) of about 50 μm to about 1.0 mm. For example, the average height may be about 50 μm, 100 μm, 200 μm, 300 μm, 400 μm, 500 μm, 600 μm, 700 μm, 800 μm, 900 μm, or 1.0 mm. Alternatively, it may be not greater than or equal to about 1.0 mm, 900 μm, 800 μm, 700 μm, 600 μm, 500 μm, 400 μm, 300 μm, 200 μm, 100 μm, or 50 μm.

[0110] At least a portion of the teeth or toothed ribs may have an average center distance within the row along the machine direction of about 100 μm to about 50 mm. For example, the average center distance may be greater than or equal to about 50 μm, 100 μm, 200 μm, 300 μm, 400 μm, 500 μm, 600 μm, 700 μm, 800 μm, 900 μm or 1.0 mm, and increase to 50 mm in similar increments. Alternatively, it may not be greater than or equal to about 50 μm, 100 μm, 200 μm, 300 μm, 400 μm, 500 μm, 600 μm, 700 μm, 800 μm, 900 μm or 1.0 mm, and increase to 50 mm in similar increments. In addition, adjacent teeth or toothed rib rows may be similarly arranged at the same position in the machine direction or offset. In an offset configuration, adjacent teeth or toothed ribs are arranged at different positions in the machine direction.

[0111] At least a portion of the teeth or toothed ribs may have an average height to base width ratio of from about 0.1:1.0 to about 500:1.0. For example, the average height to base width ratio may be about 0.1:1.0, 25:1.0, 50:1.0, 100:1.0, 150:1.0, 200:1.0, 250:1.0, 300:1.0, 350:1, 450:1.0, or 500:1.0. Alternatively, the average height to base width ratio may be not greater than or equal to about 500:1.0, 450:1.0, 400:1.0, 350:1.0, 300:1.0, 250:1.0, 200:1.0, 150:1.0, 100:1.0, 50:1.0, 25:1.0, or 0.1:1.0.

[0112] At least a portion of the teeth or toothed ribs may have an average base width to tip width ratio of from about 1,000:1.0 to about 0.1:1.0. For example, the average base width to tip width ratio may be about 0.1:1.0, 1.0:1.0, 2:1.0, 3:1.0, 4:1.0, 5:1.0, 6:1.0, 7:1.0, 8:1.0, 9:1.0, 10:1.0, 15:1.0, 20:1.0, 25:1.0, 50:1.0, 100:1.0, 150:1.0 , 200:1.0, 250:1.0, 300:1.0, 350:1.0, 450:1.0, 500:1.0, 550:1.0, 600:1.0, 650:1.0, 700:1.0, 750:1.0, 800:1.0, 850:1.0, 900:1.0, 950:1.0, or 1,000:1.0. Alternatively, the average base width to tip width ratio may be no greater than about 1,000:1.0, 950:1.0, 900:1.0, 850:1.0, 800:1.0, 750:1.0, 700:1.0, 650:1.0, 600:1.0, 550:1.0, 500:1.0, 450:1.0, 400:1.0, 350:1.0, 300:1.0 :1.0, 250:1.0, 200:1.0, 150:1.0, 100:1.0, 50:1.0, 25:1.0, 20:1.0, 15:1.0, 10:1.0, 9:1.0, 8:1.0, 7:1.0, 6:1.0, 5:1.0, 4:1.0, 3:1.0, 2:1.0, 1.0:1.0, or 0.1:1.0.

[0113] In particular embodiments, the improved separator may comprise a porous membrane which may be made from any one or more of the following: a natural or synthetic base material, a processing plasticizer, a filler, one or more natural or synthetic rubbers or latexes, a nucleating additive and / or one or more other additives and / or a coating and / or the like and combinations thereof.

[0114] In a specific embodiment, exemplary natural or synthetic substrate materials may include: polymers, thermoplastic polymers, phenolic resins, natural or synthetic rubbers, synthetic wood pulp, lignin, glass fibers, synthetic fibers, cellulose fibers, and combinations thereof. In a specific preferred embodiment, an exemplary separator may be a porous membrane made of a thermoplastic polymer. Exemplary thermoplastic polymers may in principle include all acid-resistant thermoplastic materials suitable for lead-acid batteries. In a specific preferred embodiment, exemplary thermoplastic polymers may include polyvinyl compounds and polyolefins. In a specific embodiment, polyvinyl compounds may include, for example, polyvinyl chloride (PVC). In a specific preferred embodiment, polyolefins may include, for example, polyethylene, polypropylene, ethylene-butene copolymers, and combinations thereof, but preferably polyethylene. In a specific embodiment, exemplary natural or synthetic rubbers may include, for example, latex, non-crosslinked or crosslinked rubber, crumbs or ground rubber, and combinations thereof.

[0115] In a particular embodiment, the porous membrane layer preferably comprises a polyolefin, in particular polyethylene. Preferably, the polyethylene is a high molecular weight polyethylene (HMWPE) (e.g., a polyethylene with a molecular weight of at least 600,000). Even more preferably, the polyethylene is an ultra-high molecular weight polyethylene (UHMWPE). Exemplary UHMWPE may have a molecular weight of at least 1,000,000, especially greater than 4,000,000 and most preferably 5,000,000 to 8,000,000 measured by viscometry and calculated by the Margolie equation. In addition, exemplary UHMWPE may have a standard load melt index of substantially zero (0) measured using a standard load of 2,160 g as specified in ASTM D 1238 (Condition E). Also, exemplary UHMWPE may have a viscosity value determined in a solution of 0.02 g of polyolefin dissolved in 100 g of decalin at 130° C. of not less than 600 ml / g, preferably not less than 1,000 ml / g, more preferably not less than 2,000 ml / g, and most preferably not less than 3,000 ml / g.

[0116] In particular embodiments, exemplary processing plasticizers can include processing oils, petroleum oils, paraffinic mineral oils, mineral oils, and combinations thereof.

[0117] The separator may include a filler having a high structured morphology. Exemplary fillers may include: silica, dry finely divided silica, precipitated silica, amorphous silica, highly brittle silica, alumina, talc, fish meal, fish bone meal, carbon, carbon black, and the like, and combinations thereof. In certain preferred embodiments, the filler is one or more silicas. High structured morphology refers to increased surface area. The filler may have a high surface area, for example greater than about 100 m2 / g, about 110m 2 / g, about 120m 2 / g, about 130m 2 / g, about 140m 2 / g, about 150m 2 / g, about 160m 2 / g, about 170m 2 / g, about 180m 2 / g, about 190m 2 / g, about 200m 2 / g, about 210m 2 / g, about 220m 2 / g, about 230m 2 / g, about 240m 2 / g or about 250m 2 In some embodiments, the filler (eg, silica) may have a molecular weight of about 100-300 m 2 / g, about 125-275m 2 / g, about 150-250m 2 / g or preferably about 170-220m 2 / g surface area. The surface area can be evaluated using a TriStar 3000TM to obtain a multi-point BET nitrogen surface area. High structural morphology allows the filler to accommodate more oil during the manufacturing process. For example, fillers with high structural morphology have high levels of oil absorption, such as greater than about 150 ml / 100 g, about 175 ml / 100 g, about 200 ml / 100 g, about 225 ml / 100 g, about 250 ml / 100 g, about 275 ml / 100 g, about 300 ml / 100 g, about 325 ml / 100 g, or about 350 ml / 100 g. In some embodiments, the filler (e.g., silica) may have an oil absorption rate of about 200-500 ml / 100 g, about 200-400 ml / 100 g, about 225-375 ml / 100 g, about 225-350 ml / 100 g, about 225-325 ml / 100 g, preferably about 250-300 ml / 100 g. In some cases, a silica filler having an oil absorption rate of about 266 ml / 100 g is used. This silica filler has a water content of about 5.1%, a viscosity of about 178 m 2 / g, an average particle size of about 23 μm, a 230 mesh residue of about 0.1%, and a bulk density of about 135 g / L.

[0118] When forming an exemplary lead-acid battery separator of the type shown herein, silica having a relatively high level of oil absorption and a relatively high level of affinity for a plasticizer (e.g., mineral oil) becomes ideally dispersed in a mixture of a polyolefin (e.g., polyethylene) and a plasticizer. In the past, when large amounts of silica were used to make such separators or membranes, some separators suffered from poor dispersibility caused by silica aggregation. In at least certain separators of the present invention shown and described herein, the polyolefin, such as polyethylene, forms a shish-kebab structure because there are few silica aggregates or agglomerates to inhibit the molecular motion of the polyolefin upon cooling the molten polyolefin. All of this contributes to increased ion permeability through the resulting separator film, and the formation of the shish-kebab structure or morphology means that a separator is produced in which mechanical strength is maintained or even improved while the overall ER is lower.

[0119] In some selected embodiments, the filler (e.g., silica) has an average particle size of no greater than about 25 μm, and in some cases, no greater than about 22 μm, 20 μm, 18 μm, 15 μm, or 10 μm. In some cases, the average particle size of the filler particles is 15-25 μm. The particle size of the silica filler and / or the surface area of ​​the silica filler contribute to the oil absorption of the silica filler. The silica particles in the final product or separator may fall within the sizes described above. However, the initial silica used as a raw material may appear in the form of one or more agglomerates and / or aggregates and may have a size of about 200 μm or greater.

[0120] In some preferred embodiments, the silica used to make the separator of the present invention has an increased amount or number of surface silanol groups (surface hydroxyl groups) compared to silica fillers previously used to make lead-acid battery separators. For example, silica fillers useful with certain preferred embodiments herein may be those having about at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, or at least 35% more silanol and / or hydroxyl surface groups than known silica fillers used to make known polyolefin lead-acid battery separators.

[0121] For example, the ratio (Si—OH) / Si of silanol groups (Si—OH) to silicon elements (Si) can be measured as follows.

[0122] 1. Freeze-crushing a polyolefin porous membrane (wherein a specific membrane of the present invention comprises a specific type of oil-absorbing silica according to the present invention) and preparing it for solid-state nuclear magnetic resonance spectroscopy ( 29 Si-NMR) of powdered samples.

[0123] 2. For powdered samples 29Si-NMR, and observe the spectrum, the spectrum includes the spectrum intensity of Si directly bonded to the hydroxyl group (spectra: Q2 and Q3) and the spectrum intensity of Si directly bonded only to the oxygen atom (spectrum: Q4), where the molecular structure of each NMR peak spectrum can be depicted as follows:

[0124] Q2: (SiO)2-Si*-(OH)2: has two hydroxyl groups

[0125] Q3: (SiO)3-Si*-(OH): has a hydroxyl group

[0126] Q4: (SiO)4-Si*: All Si bonds are SiO

[0127] · Wherein Si* is an element confirmed by NMR observation.

[0128] 3. For observation 29 The conditions of Si-NMR are as follows:

[0129] Instrument: Bruker BioSpin Avance 500

[0130] Resonance frequency: 99.36MHz

[0131] Sample volume: 250mg

[0132] NMR tube:

[0133] Observation method: DD / MAS

[0134] Pulse width: 45°

[0135] Repeat time: 100 seconds

[0136] Scan: 800

[0137] Magic Angle Spin: 5,000Hz

[0138] Chemical shift reference: Silicone rubber is -22.43ppm (external reference)

[0139] 4. Numerically, separate the peaks of the spectrum and calculate the area ratio of each peak belonging to Q2, Q3 and Q4. Afterwards, based on these ratios, calculate the molar ratio of hydroxyl groups (-OH) directly bonded to Si. The conditions for numerical peak separation are carried out in the following manner:

[0140] Fitting area: -80 to -130ppm

[0141] Initial peak tops: -93 ppm for Q2, -101 ppm for Q3, and -111 ppm for Q4, respectively.

[0142] Initial full width half maximum: 400 Hz for Q2, 350 Hz for Q3, and 450 Hz for Q4, respectively.

[0143] Gaussian function ratio: 80% initially and 70 to 100% during fitting.

[0144] 5. Calculate the peak area ratio of Q2, Q3 and Q4 based on each peak obtained by fitting (the total is 100). The NMR peak area corresponds to the number of molecules of each silicate bond structure (therefore, for the Q4 NMR peak, there are four Si-O-Si bonds in the silicate structure; for the Q3 NMR peak, there are three Si-O-Si bonds in the silicate structure and one Si-OH bond; for the Q2 NMR peak, there are two Si-O-Si bonds in the silicate structure and two Si-OH bonds). Therefore, the number of hydroxyl groups (-OH) of Q2, Q3 and Q4 is multiplied by two (2), one (1) and zero (0), respectively. Add these three results. The total value shows the molar ratio of hydroxyl groups (-OH) directly bonded to Si.

[0145] In certain embodiments, the silica may have 29 The molecular ratio of OH to Si groups as measured by Si-NMR may be in the range of about 21:100 to 35:100, in some preferred embodiments about 23:100 to about 31:100, in certain preferred embodiments about 25:100 to about 29:100, and in other preferred embodiments at least about 27:100 or greater.

[0146] In some selected embodiments, the use of the fillers described above enables the use of a greater proportion of processing oil in the extrusion step. Since the porous structure in the separator is formed in part by removing the oil after extrusion, a higher initial amount of absorbed oil results in a higher porosity or a higher void volume. Since the processing oil is an indispensable component of the extrusion step, the oil is a non-conductive component of the separator. The residual oil in the separator protects the separator from oxidation when in contact with the positive electrode. In the production of conventional separators, the exact amount of oil in the processing step can be controlled. Generally speaking, conventional separators are manufactured using 50-70wt% processing oil, 55-65wt% in some embodiments, 60-65wt% in some embodiments, and about 62wt% processing oil in some embodiments. It is known that reducing the oil to below about 59% can cause burning due to increased friction with the extruder components. However, increasing the oil much higher than the specified amount may cause shrinkage during the drying stage, resulting in dimensional instability. While previous attempts to increase oil content resulted in shrinkage or reduction of pores during oil removal, separators prepared as disclosed herein exhibit minimal, if any, shrinkage and reduction during oil removal. Thus, porosity can be increased without compromising pore size and dimensional stability, thereby reducing electrical resistance.

[0147] In certain selected embodiments, the use of fillers as described above can result in a lower final oil concentration in the finished separator. Since oil is a non-conductor, reducing the oil content can increase the ionic conductivity of the separator and help reduce the ER of the separator. Therefore, separators with reduced final oil content can have improved efficiency. In certain selected embodiments, separators are provided having a final process oil content (by weight) of less than 20%, such as between about 14% and 20%, and in some particular embodiments, less than 19%, 18%, 17%, 16%, 15%, 14%, 13%, 12%, 11%, 10%, 9%, 8%, 7%, 6% or 5%.

[0148] Fillers can further reduce the so-called hydration spheres of electrolyte ions, enhancing their transport across the membrane, again lowering the overall electrical impedance or ER of the cell (such as an enhanced flooded cell) or system.

[0149] The one or more fillers may include various materials (eg, polar materials such as metals) that facilitate the flow of electrolyte and ions through the separator. This also results in a reduction in overall resistance when such a separator is used in a flooded cell, such as an enhanced flooded cell.

[0150] In certain embodiments, the separator may include a conductive element or a nucleating additive and / or a performance enhancing additive in the form of a coating. The conductive element or the nucleating additive may preferably be stable in the battery electrolyte and may further be dispersed in the electrolyte.

[0151] Exemplary forms of the conductive element and / or coating can be or include carbon, such as carbon, conductive carbon, graphite, artificial graphite, activated carbon, carbon paper, acetylene black, carbon black, high surface area carbon black, graphene, high surface area graphene, keitjen black, carbon fiber, carbon filament, carbon nanotube, open cell carbon foam, carbon mat, carbon felt, carbon buckminster fullerene (buckyball), aqueous carbon suspension, flake graphite, oxidized carbon, and combinations thereof. In addition to these various forms of carbon, the nucleating additive and / or coating can also include or include barium sulfate (BaSO4), alone or in combination with carbon. An exemplary form of carbon is manufactured by Cabot Corporation of Boston, MA, USA. -135. An exemplary preferred form of carbon is manufactured by Cabot Corporation of Boston, MA, USA -51. The inventors infer that the greater the surface area of ​​the carbon, the greater the dynamic charge acceptance in the battery. For example, -51 has at least about 1,300m 2 / g to about 1,500m 2 / g, while Keitjen Black has a specific surface area of ​​at least about 1,250 m 2 / g of surface area.

[0152] The nucleating coating can be applied to the final separator by such means as slurry coating, slot die coating, spray coating, curtain coating, inkjet printing, screen printing or by vacuum deposition or chemical vapor deposition (CVD). In addition, the additive and / or coating can be provided as a woven or non-woven carbon paper and disposed between the separator and the electrode and in close contact therewith.

[0153] The nucleating additive and / or coating may be within the separator, or on one or both surfaces of the separator facing the electrode. Typically, the coating or layer of the nucleating additive may be only on the surface facing the negative electrode. However, it may be on the surface facing the positive electrode, or on both surfaces.

[0154] In a particular embodiment, the nucleating additive can be added to the extrusion mixture of the substrate and extruded with the separator, or coextruded as a layer on the separator. When included in the extrusion mixture, the nucleating additive can replace 5% to 75% of some silica fillers by weight. For example, the nucleating additive can be about 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70% or about 75% by weight. In other exemplary embodiments, the nucleating additive may be no more than about 75%, 70%, 65%, 60%, 55%, 50%, 45%, 40%, 35%, 30%, 25%, 20%, 15%, 10% or about 5% by weight.

[0155] Figures 3A-3C is a scanning electron microscope (SEM) image of graphite 100. Figure 3D is a SEM image of artificial graphite. Figure 3E are SEM images of acetylene black. These images were taken at 1,000x zoom. It can be seen that Graphite 100 and artificial graphite have similar structures and appear to have similar surface roughness and surface area on which lead sulfate can nucleate. However, acetylene black exhibits a generally rougher surface and therefore more surface area on which lead sulfate can nucleate, which can provide more nucleation sites.

[0156] Figures 4A-4C is a SEM image of a lead electrode after 100 charge / discharge cycles, showing the growth of lead sulfate crystals on the electrode. Figure 4A and 4B The SEM images were taken at 15.0 kV with a 5,000x zoom. Figure 4A is a control lead electrode in the absence of any carbon additive and / or coated separator. Figure 4B is an image of a lead electrode in the presence of a separator coated with carbon black. Figure 4C is a SEM image of a lead electrode in the presence of a separator coated with artificial graphite (taken at 15.0 kV with 5,500x zoom). It can be seen that the size of the lead sulfate crystals is smaller in the presence of carbon compared to the control sample.

[0157] Figures 5A-5C Figure 1 is an SEM image of a lead-acid separator after 100 charge / discharge cycles, showing the growth of lead sulfate crystals on the separator. These SEM images were taken at 15.0 kV with 1,000x zoom. Figure 5A is a control separator without any carbon added. Figure 5B is a separator with 5% carbon added to the extrusion mix, Figure 5Cis an image of a separator with 10% carbon added to the extrusion mix. It can be seen that the higher the carbon content, the smaller and fewer lead sulfate crystals are produced.

[0158] Figures 6A-6C are SEM images of a lead electrode after 100 charge / discharge cycles, showing the growth of lead sulfate crystals on the electrode. These SEM images were taken at 15.0 kV with 10,000x zoom. Fig. 6A is a SEM image of a control lead electrode in the presence of a separator without carbon additives and / or coating. Figure 6B is a SEM image of a lead electrode in the presence of a separator having 5% carbon in the extruded mix. Figure 6C is a SEM image of a lead electrode in the presence of a separator with 10% carbon in the extrusion mix. It can be seen that the higher the carbon content, the smaller and fewer lead sulfate crystals are produced.

[0159] A conductive layer may be disposed on the exemplary battery separator 100. The conductive layer may preferably be adapted to contact the positive electrode (not shown) of the battery. The conductive layer may be used to provide a new path for current to enter and exit the positive electrode (not shown). The conductive layer may be made of any conductive material, including but not limited to, aluminum oxide, lead, gold, antimony, arsenic, zinc, barium, beryllium, lithium, magnesium, nickel, aluminum, silver, tin, and combination alloys thereof, or carbon fiber, graphite, carbon nanotubes, buckminster fullerene (or buckyballs), and combinations thereof. The carbon nanotubes or buckyballs may be dispersed in a medium with a binder and coated on the battery separator. The conductive layer may be made of any conductive material that is more corrosion resistant than the positive conductor, thereby enabling the conductive layer to function as a positive conductor when the conductivity of the positive conductor deteriorates. The conductive layer may be a lead-based alloy having 0.8% to 1.17% tin and greater than zero (0) to 0.015% silver. The conductive layer can be a lead-based alloy with 0.02% to 0.06% calcium, 0.3% to 3% tin, and 0.01% to 0.05% silver. The conductive layer can be made into any form, including but not limited to tape, screen, foil, wire, filament, coating, etc. or a combination thereof. The conductive layer can be any thickness, for example, a thickness of about 3 μm. The conductive layer can be disposed on the battery separator by any means, including but not limited to bonding, hot melting, coating, etc. The conductive layer can be as described in U.S. Patent No. 9,564,623 (which is incorporated herein by reference in its entirety).

[0160] The new separator disclosed herein may contain latex and / or rubber. When used herein, "rubber" will describe rubber, latex, natural rubber, synthetic rubber, crosslinked or non-crosslinked rubber, cured or non-cured rubber, crumb or ground rubber or mixtures thereof. Exemplary natural rubber may include blends of one or more polyisoprenes, which are commercially available from different suppliers. Exemplary synthetic rubbers include methyl rubber, polybutadiene, chloroprene rubber, butyl rubber, bromobutyl rubber, polyurethane rubber, epichlorohydrin rubber, polysulfide rubber, chlorosulfonyl polyethylene, polynorbornene rubber, acrylate rubber, fluororubber and silicone rubber and copolymer rubbers such as styrene / butadiene rubber, acrylonitrile / butadiene rubber, ethylene / propylene rubber (EPM and EPDM) and ethylene / vinyl acetate rubber. The rubber may be a crosslinked rubber or a non-crosslinked rubber, and in a specific preferred embodiment, the rubber is a non-crosslinked rubber. In a specific embodiment, the rubber may be a blend of crosslinked and non-crosslinked rubbers.

[0161] In certain embodiments, the exemplary separator may include one or more performance enhancing additives added to the separator or porous membrane. The performance enhancing additive may be a surfactant, a wetting agent, a colorant, an antistatic additive, an antimony suppression additive, an ultraviolet protection additive, an antioxidant and / or the like and combinations thereof. In certain embodiments, the additive surfactant may be an ionic, cationic, anionic or nonionic surfactant.

[0162] In certain embodiments described herein, a reduced amount of anionic or nonionic surfactant is added to the porous membrane or separator of the present invention. Due to the lower amount of surfactant, desirable characteristics may include reduced total organic carbon (TOC) and / or reduced volatile organic compounds (VOC).

[0163] Specific suitable surfactants are nonionic, while other suitable surfactants are anionic. The additive can be a single surfactant or a mixture of two or more surfactants, such as two or more anionic surfactants, two or more nonionic surfactants or at least one ionic surfactant and at least one nonionic surfactant. Specific suitable surfactants may have an HLB value of less than 6, preferably less than 3. The use of these specific suitable surfactants in conjunction with the separator of the present invention described herein can produce further improved separators, which, when used in lead-acid batteries, bring reduced water consumption, reduced antimony poisoning, improved circulation, reduced float current, reduced float voltage and / or the like or any combination thereof to the lead-acid battery. Suitable surfactants include surfactants such as alkyl sulfates, alkyl aryl sulfonates, alkylphenol-alkylene oxide addition products, soaps, alkyl naphthalene sulfonates, one or more sulfosuccinates, such as anionic sulfosuccinates, dialkyl esters of sulfosuccinates, amino compounds (primary, secondary, tertiary or quaternary amines), block copolymers of ethylene oxide and propylene oxide, various polyethylene oxides, and salts of mono- and dialkyl phosphates. Additives may include nonionic surfactants such as polyol fatty acid esters, polyethoxylated esters, polyethoxylated alcohols, alkyl polysaccharides such as alkyl polyglycosides and mixtures thereof, amine ethoxylates, sorbitan fatty acid ester ethoxylates, silicone-based surfactants, ethylene vinyl acetate terpolymers, ethoxylated alkyl aryl phosphates of fatty acids, and sucrose esters.

[0164] In certain embodiments, the additive may be represented by a compound of formula (I).

[0165]

[0166] in:

[0167] R is a linear or non-aromatic hydrocarbon radical having 10 to 4200 carbon atoms, preferably 13 to 4200 carbon atoms, which may be interrupted by oxygen atoms;

[0168] · or Preferably H, where k = 1 or 2;

[0169] M is an alkali metal or alkaline earth metal ion, H + or Not all variables M are H at the same time + ;

[0170] n = 0 or 1;

[0171] m = 0 or an integer from 10 to 1400; and

[0172] x = 1 or 2.

[0173] In the compounds according to formula (I), the ratio of oxygen atoms to carbon atoms is in the range of 1:1.5 to 1:30, and m and n cannot simultaneously be 0. However, it is preferred that only one of the variables n and m is not equal to zero.

[0174] By non-aromatic hydrocarbon radical is meant a radical which does not contain an aromatic group or which itself represents an aromatic group. The hydrocarbon radical may be interrupted by oxygen atoms (ie contain one or more ether groups).

[0175] R is preferably a straight-chain or branched aliphatic hydrocarbon radical which may be interrupted by oxygen atoms. Saturated, non-crosslinked hydrocarbon radicals are very particularly preferred. However, as mentioned above, in a particular embodiment, R may be aromatic ring-containing.

[0176] By using the compound of formula (I) in the production of battery separators, the separators can be effectively protected from oxidative damage.

[0177] Battery separators comprising compounds according to formula (I) are preferred wherein:

[0178] R is a hydrocarbon radical having 10 to 180, preferably 12 to 75 and very particularly preferably 14 to 40 carbon atoms, which may be interrupted by 1 to 60, preferably 1 to 20 and very particularly preferably 1 to 8 oxygen atoms, particularly preferably a radical of the formula R 2 —[(OC2H4) p (OC3H6) q ]—hydrocarbyl, wherein:

[0179] οR 2 is an alkyl group having 10 to 30 carbon atoms, preferably 12 to 25, particularly preferably 14 to 20 carbon atoms, wherein R 2 It can be linear or nonlinear such as containing aromatic rings;

[0180] οP is an integer from 0 to 30, preferably from 0 to 10, particularly preferably from 0 to 4; and

[0181] oq is an integer from 0 to 30, preferably from 0 to 10, particularly preferably from 0 to 4;

[0182] o Compounds in which the sum of p and q is from 0 to 10, in particular from 0 to 4, are particularly preferred;

[0183] n = 1; and

[0184] ·m=0.

[0185] Formula R 2 —[(OC2H4) p (OC6H6) q]—should be understood to also include those compounds in which the sequence of the radicals in the square brackets is different from that shown. For example, compounds in which the free radicals in the brackets are formed by alternating (OC2H4) and (OC3H6) groups are suitable according to the invention.

[0186] It has been confirmed that R 2 Additives which are straight-chain or branched alkyl radicals having 10 to 20, preferably 14 to 18, carbon atoms are particularly advantageous. OC2H4 preferably represents OCH2CH2, and OC3H6 represents OCH(CH3)2 and / or OCH2CH2CH3.

[0187] As preferred additives, mention may be made here in particular of: alcohols (p=q=0; m=0), primary alcohols being particularly preferred; fatty alcohol ethoxylates (p=1 to 4, q=0); fatty alcohol propoxylates (p=0; q=1 to 4); and fatty alcohol alkoxylates (p=1 to 2; q=1 to 4), primary alcohol ethoxylates being preferred. Fatty alcohol alkoxylates are obtainable, for example, by reaction of the corresponding alcohols with ethylene oxide or propylene oxide.

[0188] Additives of the m=0 type which are insoluble or only sparingly soluble in water and sulfuric acid have proven to be particularly advantageous.

[0189] Also preferred are additives containing compounds according to formula (I), wherein:

[0190] R is an alkyl radical having 20 to 4200, preferably 50 to 750 and very particularly preferably 80 to 225 carbon atoms;

[0191] M is an alkali metal or alkaline earth metal ion, H + or Especially Li + 、Na + and K + Alkali metal ions or H + , where not all variables M are H at the same time + ;

[0192] n = 0;

[0193] m is an integer from 10 to 1400; and

[0194] x = 1 or 2.

[0195] In a particular embodiment, suitable additives may include, in particular, polyacrylic acid, polymethacrylic acid and acrylic acid-methacrylic acid copolymers, whose acid groups are at least partially, for example, preferably 40% and particularly preferably 80%, neutralized. The percentage refers to the number of acid groups. Very particularly preferred is poly(meth)acrylic acid that is completely in the form of a salt. Suitable salts include Li, Na, K, Rb, Be, Mg, Ca, Sr, Zn and ammonium (NR4, where R is a hydrogen or carbon functional group). Poly(meth)acrylic acid may include polyacrylic acid, polymethacrylic acid and acrylic acid-methacrylic acid copolymers. Poly(meth)acrylic acid is preferred and in particular has an average molar mass M of 1,000 to 100,000 g / mol, particularly preferably 1,000 to 15,000 g / mol and very particularly preferably 1,000 to 4,000 g / mol. w The molecular weight of poly(meth)acrylic acid polymers and copolymers was determined by measuring the viscosity (Fikentscher constant) of a 1% aqueous solution of the polymer neutralized with sodium hydroxide solution.

[0196] Likewise suitable are copolymers of (meth)acrylic acid, in particular copolymers which, in addition to (meth)acrylic acid, contain ethylene, maleic acid, methyl acrylate, ethyl acrylate, butyl acrylate and / or ethylhexyl acrylate as comonomers. Copolymers containing at least 40% by weight and preferably at least 80% by weight of (meth)acrylic acid monomers are preferred, the percentages being based on the acid form of the monomers or polymers.

[0197] For neutralizing the polyacrylic acid polymers and copolymers, alkali metal and alkaline earth metal hydroxides such as potassium hydroxide and especially sodium hydroxide are particularly suitable. In addition, the coating and / or additives used to strengthen the separator may include, for example, metal alkoxides, where the metal may be Zn, Na or Al, such as sodium ethoxide, by way of example only (without intent to be limiting).

[0198] In some embodiments, the porous polyolefin porous membrane may include a coating on one or both sides of such a layer. Such a coating may include a surfactant or other material. In some embodiments, the coating may include one or more materials described, for example, in U.S. Patent No. 9,876,209 (incorporated herein by reference). Such a coating may, for example, reduce the overcharge voltage of the battery system, thereby extending the battery life due to less grid corrosion and preventing dry-out and / or water loss.

[0199] In certain selected embodiments, the film can be prepared by combining about 5-15% polymer by weight [in some cases, about 10% polymer (e.g., polyethylene)], about 10-75% filler [(e.g., silica), in some cases, about 30% filler], and about 10-85% process oil (in some cases, about 60% process oil). In other embodiments, the filler content is reduced and the oil content is higher, such as greater than about 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69%, or 70% by weight. The filler: polymer ratio (by weight) can be about (or can be between about these specific ranges), such as 2: 1, 2.5: 1, 3: 1, 3.5: 1, 4.0: 1, 4.5: 1, 5.0: 1, 5.5: 1, or 6: 1. The filler: polymer ratio (by weight) may be from about 1.5: 1 to about 6: 1, in some cases from 2: 1 to 6: 1, from about 2: 1 to 5: 1, from about 2: 1 to 4: 1, and in some cases from about 2: 1 to about 3: 1. The amounts of filler, oil, and polymer are all balanced for runnability and desired separator properties such as electrical resistance, basis weight, puncture resistance, flexural stiffness, oxidation resistance, porosity, physical strength, bendability, etc.

[0200] According to at least one embodiment, the porous film may include UHMWPE mixed with processing oil and precipitated silica. According to at least one embodiment, the porous film may include UHMWPE mixed with processing oil, additives and precipitated silica. The mixture may also include a small amount of other additives or reagents common in the separator field (such as surfactants, wetting agents, colorants, antistatic additives, antioxidants and / or the like and combinations thereof). In certain cases, the porous polymer layer can be a homogeneous mixture of about 8 to about 100 volume % of polyolefin, about 0 to about 40 volume % of plasticizer and about 0 to about 92 volume % of inert filler material. A preferred plasticizer is petroleum. Since the plasticizer is the component that is most easily removed from the polymer-filler-plasticizer composition by solvent extraction and drying, it is useful in giving the battery separator with porosity.

[0201] In a specific embodiment, the porous membrane disclosed herein may include latex and / or rubber, which may be natural rubber, synthetic rubber or a mixture thereof. Natural rubber may include one or more blends of polyisoprene, which may be commercially available from different suppliers. Exemplary synthetic rubbers include methyl rubber, polybutadiene, chloroprene rubber, butyl rubber, bromobutyl rubber, polyurethane rubber, epichlorohydrin rubber, polysulfide rubber, chlorosulfonyl polyethylene, polynorbornene rubber, acrylate rubber, fluororubber and silicone rubber and copolymer rubbers such as styrene / butadiene rubber, acrylonitrile / butadiene rubber, ethylene / propylene rubber (EPM and EPDM) and ethylene / vinyl acetate rubber. Rubber may be crosslinked rubber or non-crosslinked rubber. In a specific preferred embodiment, rubber is non-crosslinked rubber. In a specific embodiment, rubber may be a blend of crosslinked and non-crosslinked rubber. The rubber may be present in the separator in an amount of at least about 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9% or about 10% by weight relative to the final separator weight (the weight of the polyolefin separator sheet or layer containing rubber and / or latex). In specific embodiments, the rubber may be present in an amount of about 1-6wt%, about 3-6wt%, about 3wt% and about 6wt%. The porous membrane may have a weight ratio of filler to polymer and rubber (filler: polymer and rubber) of about 2.6:1.0. The amounts of rubber, filler, oil and polymer are balanced for operability and desired separator properties (such as resistance, basis weight, puncture resistance, flexural stiffness, oxidation resistance, porosity, physical strength, bending, etc.).

[0202] The porous membranes containing polyethylene and fillers (e.g., silica) manufactured according to the present invention typically have a residual oil content; in some embodiments, this residual oil content is from about 0.5% to about 40% of the total weight of the separator membrane (in some cases, about 10-40% of the total weight of the separator membrane, and in some cases, about 20-40% of the total weight). In certain selected embodiments herein, some to all of the residual oil content in the separator can be replaced by adding more performance enhancing additives (such as surfactants, such as surfactants having a hydrophilic-lipophilic balance (HLB) of less than about 6 or, for example, nonionic surfactants). For example, performance enhancing additives such as surfactants, such as nonionic surfactants, can account for 0.5% to all of the residual oil content of the total weight of the porous separator membrane (e.g., up to 20% or 30% or even 40%), thereby partially or completely replacing the residual oil in the separator membrane.

[0203] Exemplary separators may be provided with a porous membrane web, such as a microporous membrane having pores less than about 5 μm, preferably less than about 1 μm, a mesoporous membrane, or a macroporous membrane having pores greater than about 1 μm. The porous membrane may preferably have a pore size of submicron up to 100 μm, and in a particular embodiment, the pore size is between about 0.1 μm and about 10 μm. In a particular embodiment, the porosity of the separator membrane described herein may be greater than about 50% to about 70%. In a particular selected embodiment, the porous membrane may be flat or have ribs extending from its surface. As in Figures 6A-6C As shown in , the spacer can be defined by various dimensions, which will be explained in detail below. For example, the spacer can have a back mesh thickness T BACK , total thickness T TOTAL , positive electrode rib height H POS 、Positive electrode rib bottom width W POSBASE 、Positive electrode rib spacing P POS 、Negative electrode rib height H NEG , negative electrode rib bottom width (not shown) and negative electrode rib spacing P NEG .

[0204] See Figures 6A-6C , an exemplary separator 100 is provided with a web of porous membrane 102. The separator 100 and membrane 102 have a machine direction (MD) and a cross-machine direction (CMD), a top edge 101 and a bottom edge 103 (both substantially parallel to the CMD), and transverse edges 105a, 105b (both substantially parallel to the MD).

[0205] refer to Fig. 7A , the separator 100 is provided with a positive electrode surface, so named because when the separator 100 is disposed in a battery (not shown), it faces the positive electrode (not shown). Fig. 7A The positive surface of the separator is depicted. One or more sets of main ribs or positive ribs 104 may be provided and extend from at least a portion of the positive surface of the porous membrane 102. As shown, the ribs 104 are solid and are disposed substantially longitudinally on the membrane 102, substantially parallel to the separator MD. The positive ribs 104 are also depicted as extending uniformly across the separator width W from transverse edge 105a to transverse edge 105, which is referred to as a "universal profile". As shown in FIG. Figure 7C As shown in FIG. 1 , in at least selected embodiments, the separator 100 has a width W that can range from about 40 mm to about 170 mm, depending on the type of battery in which the separator 100 is used.

[0206] refer to Figure 7B , the separator 100 is provided with a negative electrode surface, so named because when the separator 100 is disposed in a battery (not shown), it faces the negative electrode (not shown). Figure 7BThe negative electrode surface of the separator is described. One or more groups of secondary ribs or negative electrode ribs 106 may be provided and extend from at least a portion of the negative electrode surface of the porous membrane 102. The ribs 104 shown are solid and are arranged in a direction orthogonal to the positive electrode ribs 104, substantially parallel to the separator CMD. Therefore, these ribs can be said to be arranged transversely, laterally, or referred to as cross ribs or negative cross ribs (NCR or NCRs). However, the negative electrode ribs 106 do not need to be orthogonal to the positive electrode ribs 104. They can be the same size, larger, smaller, in the same or different configurations, or a combination thereof.

[0207] The ribs 104, 106 may be a uniform group, alternating groups, or a mixture or combination of the following ribs: solid, discrete discontinuous ribs, continuous, discontinuous, angled, linear, longitudinal ribs extending substantially along the MD of the separator, transverse ribs extending substantially along the cross-machine direction CMD of the separator, transverse ribs extending substantially along the CMD of the separator, cross-ribs extending substantially along the cross-machine direction of the separator, serrated protrusions or serrated ribs, stacked protrusions or stacked ribs, curved or sinusoidal, arranged in a solid or discontinuous zigzag manner, grooves, grooves, textured areas, protrusions, depressions, porous, non-porous, micro-ribs or cross-micro-ribs and / or the like and combinations thereof. In addition, the ribs 104, 106 may extend from or into the positive side, the negative side, or both sides.

[0208] Reference Figures 8A-8E , which depicts several embodiments of ribbed separators having different rib profiles. It may be preferred that the ribs shown are positive electrode ribs 104. Figures 8A-8C An angled rib pattern may be possible preferred RipTide TM Acid mixing rib profiles can help reduce or eliminate acid stratification in a particular battery. In some embodiments, the ribs can be discrete discontinuous ribs having an angular orientation relative to the separator MD. The angular orientation can be an angle between greater than zero degrees (0°) and less than one hundred and eighty degrees (180°) or greater than one hundred and eighty degrees (180°) and less than three hundred and sixty degrees (360°). Figures 8A-8C As further shown in the figure, the ribs can have one or more groups of ribs, each group of ribs having varying angular orientations and positions on the separator. The negative side can have no ribs (smooth), identical ribs, smaller ribs, longitudinal micro-ribs, cross micro-ribs or NCR, diagonal ribs or a combination thereof.

[0209] Fig.8D The profile of the longitudinal serrated rib pattern is depicted. Fig. 8E The profile of a diagonally offset rib pattern is shown. The negative side can have no ribs (smooth), identical ribs, smaller ribs, longitudinal micro-ribs, cross micro-ribs or NCR, diagonal ribs or a combination thereof.

[0210] As discussed above, the ribs can extend uniformly across the width of the partition from lateral edge to lateral edge. This is referred to as a universal profile. Alternatively, the partition may have side panels adjacent to the lateral edges in which smaller ribs are disposed. These smaller ribs can be more closely spaced and smaller than the main ribs. For example, the smaller ribs can be 25% to 50% of the height of the main ribs. The side panels can alternatively be flat. The side panels can assist in sealing one edge of the partition to the other edge of the partition as is done when packaging the partition, which will be discussed below.

[0211] In selected exemplary embodiments, at least a portion of the positive electrode rib may preferably have a height of about 50 μm to about 2.0 mm ( Figure 7C H POS ). In some exemplary embodiments, the positive electrode rib height H POS It may be about 50 μm, 100 μm, 200 μm, 300 μm, 400 μm, 500 μm, 600 μm, 700 μm, 800 μm, 900 μm, 1.0 mm, 1.2 mm, 1.4 mm, 1.6 mm, 1.8 mm or about 2.0 mm. In other exemplary embodiments, the positive electrode rib height H POS It may be no greater than about 2.0 mm, 1.8 mm, 1.6 mm, 1.4 mm, 1.2 mm, 1.0 mm, 900 μm, 800 μm, 700 μm, 600 μm, 500 μm, 400 μm, 300 μm, 200 μm, 100 μm, or about 50 μm.

[0212] In certain selected embodiments, the positive electrode ribs may preferably have a base width of about 300 μm to about 750 μm. Figure 6C W POSBASE ). In some exemplary embodiments, the positive electrode rib bottom width may be about 300 μm, 400 μm, 500 μm, 600 μm, 700 μm, or about 750 μm. In some exemplary embodiments, the positive electrode rib bottom width may be no greater than about 750 μm, 700 μm, 600 μm, 500 μm, 400 μm, or about 300 μm.

[0213] If a portion of the positive electrode ribs are substantially straight and substantially parallel to each other, they may have a separation length or pitch of about 50 μm to about 20 mm ( Figure 7C P POSIn some exemplary embodiments, the positive electrode rib spacing may be about 50 μm, 100 μm, 200 μm, 300 μm, 400 μm, 500 μm, 600 μm, 700 μm, 800 μm, 900 μm, 1.0 mm, 2.0 mm, 3.0 mm, 4.0 mm, or 5.0 mm, 6.0 mm, 7.0 mm, 8.0 mm, 9.0 mm, or 10.0 mm, 11.0 mm, 12.0 mm, 13.0 mm, 14.0 mm, or 15.0 mm, 16.0 mm, 17.0 mm, 18.0 mm, 19.0 mm, or about 20.0 mm. In other exemplary embodiments, the positive rib spacing may be no greater than about 20.0 mm, 19.0 mm, 18.0 mm, 17.0 mm, 16.0 mm, 15.0 mm, 14.0 mm, 13.0 mm, 12.0 mm, 11.0 mm, 10.0 mm, 9.0 mm, 8.0 mm, 7.0 mm, 6.0 mm, 5.0 mm, 4.0 mm, 3.0 mm, 2.0 mm, 1.0 mm, 900 μm, 800 μm, 700 μm, 600 μm, 500 μm, 400 μm, 300 μm, 200 μm, 100 μm, or about 50 μm.

[0214] In selected exemplary embodiments, at least a portion of the negative electrode ribs may preferably have a height of about 5% to about 100% of the height of the positive electrode ribs. In some exemplary embodiments, the height of the negative electrode ribs may be about 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 95% or about 100% compared to the height of the positive electrode ribs. In other exemplary embodiments, the height of the negative electrode ribs may be no greater than about 100%, 95%, 90%, 85%, 80%, 75%, 70%, 65%, 60%, 55%, 50%, 45%, 40%, 35%, 30%, 25%, 20%, 15%, 10% or about 5% compared to the height of the positive electrode ribs.

[0215] In selected exemplary embodiments, at least a portion of the negative electrode rib may preferably have a height of about 5 μm to about 1.0 mm ( Figure 7C H NEG In certain embodiments, the height H of the negative electrode ribs is NEG The positive electrode rib height H may be about 5 μm, 10 μm, 25 μm, 50 μm, 100 μm, 200 μm, 300 μm, 400 μm, 500 μm, 600 μm, 700 μm, 800 μm, 900 μm, 1.0 mm, 1.2 mm, 1.4 mm, 1.6 mm, 1.8 mm, or about 2.0 mm. In other exemplary embodiments, the positive electrode rib height H NEGIt may be no greater than about 2.0 mm, 1.8 mm, 1.6 mm, 1.4 mm, 1.2 mm, 1.0 mm, 900 μm, 800 μm, 700 μm, 600 μm, 500 μm, 400 μm, 300 μm, 200 μm, 100 μm or 50 μm, 25 μm, 10 μm or about 5 μm.

[0216] In certain exemplary embodiments, at least a portion of the negative electrode rib may preferably have a bottom width of about 5 μm to about 1.0 mm. For example, the bottom width of the negative electrode may be about 5 μm, 10 μm, 25 μm, 25 μm, 75 μm, 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm, 500 μm, 550 μm, 600 μm, 650 μm, 700 μm, 750 μm, 800 μm, 850 μm, 900 μm, 950 μm, or about 1.0 mm. In other embodiments, the bottom width of the negative electrode may be no greater than about 1.0 mm, 900 μm, 800 μm, 700 μm, 600 μm, 500 μm, 400 μm, 300 μm, 200 μm, 150 μm, 100 μm, 75 μm, 50 μm, 25 μm, 10 μm, or about 5 μm.

[0217] If a portion of the negative electrode ribs are substantially straight and substantially parallel to each other, they may have a separation length or pitch of about 50 μm to about 20.0 mm ( Figure 7B P NEG In some exemplary embodiments, the negative electrode rib spacing may be about 50 μm, 100 μm, 200 μm, 300 μm, 400 μm, 500 μm, 600 μm, 700 μm, 800 μm, 900 μm, 1.0 mm, 2.0 mm, 3.0 mm, 4.0 mm, or 5.0 mm, 6.0 mm, 7.0 mm, 8.0 mm, 9.0 mm, or 10.0 mm, 11.0 mm, 12.0 mm, 13.0 mm, 14.0 mm, or 15.0 mm, 16.0 mm, 17.0 mm, 18.0 mm, 19.0 mm, or about 20.0 mm. In other embodiments, the negative electrode rib spacing may be no greater than about 20.0 mm, 19.0 mm, 18.0 mm, 17.0 mm, or 16.0 mm, 15.0 mm, 14.0 mm, 13.0 mm, 12.0 mm, or 11.0 mm, 10.0 mm, 9.0 mm, 8.0 mm, 7.0 mm, or 6.0 mm, 5.0 mm, 4.0 mm, 3.0 mm, 2.0 mm, 1.0 mm, 900 μm, 800 μm, 700 μm, 600 μm, 500 μm, 400 μm, 300 μm, 200 μm, 100 μm, or about 50 μm.

[0218] In some selected embodiments, at least a portion of the porous membrane may have a negative electrode rib that is longitudinal or cross-cut or cross-ribbed. The negative electrode rib may be parallel to the top edge of the separator, or may be arranged at an angle thereto. For example, the negative electrode rib may be oriented about 0°, 5°, 15°, 25°, 30°, 45°, 60°, 70°, 80°, or 90° relative to the top edge. The cross-rib may be oriented about 0° to about 30°, about 30° to about 45°, about 45° to about 60°, about 30° to about 60°, about 30° to about 90°, or about 60° to about 90° relative to the top edge.

[0219] Specific exemplary embodiments may have serrated protrusions or serrated ribs. If present, they may have an average tip length from about 50 μm to about 1.0 mm. For example, the average tip length may be greater than or equal to about 50 μm, 100 μm, 200 μm, 300 μm, 400 μm, 500 μm, 600 μm, 700 μm, 800 μm, 900 μm, or about 1.0 mm. Alternatively, it may not be greater than or equal to 1.0 mm, 900 μm, 800 μm, 700 μm, 600 μm, 500 μm, 400 μm, 300 μm, 200 μm, 100 μm, or about 50 μm.

[0220] At least a portion of the serrations or serrated ribs may have an average base length of about 50 μm to about 1.0 mm. For example, the average base length may be about 50 μm, 100 μm, 200 μm, 300 μm, 400 μm, 500 μm, 600 μm, 700 μm, 800 μm, 900 μm, or 1.0 mm. Alternatively, it may be not greater than or equal to about 1.0 mm, 900 μm, 800 μm, 700 μm, 600 μm, 500 μm, 400 μm, 300 μm, 200 μm, 100 μm, or about 50 μm.

[0221] At least a portion of the serrated protrusions or serrated ribs may have an average height of about 50 μm to about 1.0 mm. For example, the average height may be about 50 μm, 100 μm, 200 μm, 300 μm, 400 μm, 500 μm, 600 μm, 700 μm, 800 μm, 900 μm, or about 1.0 mm. Alternatively, it may be not greater than or equal to about 1.0 mm, 900 μm, 800 μm, 700 μm, 600 μm, 500 μm, 400 μm, 300 μm, 200 μm, 100 μm, or about 50 μm. For embodiments in which the height of the serrated protrusions is the same as the height of the ribs, the serrated ribs may also be referred to as protrusions. This range may be applied to industrial traction start / stop batteries (where the total thickness of the separator T TOTAL Typically, it can be about 1 mm to about 4 mm) and automotive start / stop batteries (where the total thickness of the separator is T TOTALThe spacer may be slightly less, for example, typically about 0.3 mm to about 1 mm).

[0222] At least a portion of the serrations or serrated ribs may have an average center distance within a column in the machine direction of from about 100 μm to about 50 mm. For example, the average center distance may be greater than or equal to about 50 μm, 100 μm, 200 μm, 300 μm, 400 μm, 500 μm, 600 μm, 700 μm, 800 μm, 900 μm, or about 1.0 mm, and in similar increments up to about 50 mm. Alternatively, it may not be greater than or equal to about 50 μm, 100 μm, 200 μm, 300 μm, 400 μm, 500 μm, 600 μm, 700 μm, 800 μm, 900 μm, or about 1.0 mm, and in similar increments up to 50 mm. In addition, adjacent columns of serrations or serrated ribs may be similarly disposed in the same position in the machine direction or offset. In an offset configuration, adjacent serrations or serrated ribs are disposed at different positions along the machine direction.

[0223] At least a portion of the serrations or serrated ribs may have an average height to base width ratio of about 0.1:1.0 to about 500:1.0. For example, the average height to base width ratio may be about 0.1:1.0, 25:1.0, 50:1.0, 100:1.0, 150:1.0, 200:1.0, 250:1.0, 300:1.0, 350:1, 450:1.0, or 500:1.0. Alternatively, the ratio of average height to base width may be no greater than or equal to about 500:1.0, 450:1.0, 400:1.0, 350:1.0, 300:1.0, 250:1.0, 200:1.0, 150:1.0, 100:1.0, 50:1.0, 25:1.0, or about 0.1:1.0.

[0224] At least a portion of the serrations or serrated ribs may have an average base width to tip width ratio of from about 1,000:1.0 to about 0.1:1.0. For example, the average base width to tip width ratio may be about 0.1:1.0, 1.0:1.0, 2:1.0, 3:1.0, 4:1.0, 5:1.0, 6:1.0, 7:1.0, 8:1.0, 9:1.0, 10:1.0, 15:1.0, 20:1.0, 25:1.0, 50:1.0, 100:1.0, 150:1.0 , 200: 1.0, 250: 1.0, 300: 1.0, 350: 1.0, 450: 1.0, 500: 1.0, 550: 1.0, 600: 1.0, 650: 1.0, 700: 1.0, 750: 1.0, 800: 1.0, 850: 1.0, 900: 1.0, 950: 1.0 or about 1,000: 1.0. Alternatively, the average base width to tip width ratio may be no greater than about 1,000:1.0, 950:1.0, 900:1.0, 850:1.0, 800:1.0, 750:1.0, 700:1.0, 650:1.0, 600:1.0, 550:1.0, 500:1.0, 450:1.0, 400:1.0, 350:1.0, 300:1.0 :1.0, 250:1.0, 200:1.0, 150:1.0, 100:1.0, 50:1.0, 25:1.0, 20:1.0, 15:1.0, 10:1.0, 9:1.0, 8:1.0, 7:1.0, 6:1.0, 5:1.0, 4:1.0, 3:1.0, 2:1.0, 1.0:1.0 or about 0.1:1.0.

[0225] In some embodiments, the porous separator membrane may have a back web thickness T from about 50 μm to about 1.0 mm. BACK For example, the back mesh thickness T BACK It may be about 50 μm, 100 μm, 200 μm, 300 μm, 400 μm, 500 μm, 600 μm, 700 μm, 800 μm, 900 μm or about 1.0 mm. In other exemplary embodiments, the back web thickness T BACK It may be no greater than about 1.0 mm, 900 μm, 800 μm, 700 μm, 600 μm, 500 μm, 400 μm, 300 μm, 200 μm, 100 μm or about 50 μm. However, in certain embodiments, a very thin and flat back web thickness of 50 μm or less is provided, for example, between about 10 μm and about 50 μm thick.

[0226] The separator 100 can be configured as a flat plate, a sheet or a leaf, a coating, a sleeve, or as a sleeve or bag-like separator. An exemplary sleeve separator can encapsulate a positive electrode (positive electrode encapsulation separator), which makes the separator have two inner sides facing the positive electrode and two outer sides facing the adjacent negative electrode. Alternatively, another exemplary sleeve separator can encapsulate a negative electrode (negative electrode encapsulation separator), which makes the separator have two inner sides facing the negative electrode and two outer sides facing the adjacent positive electrode. In such an encapsulated separator, the bottom edge 103 can be a folded or sealed crease edge. In addition, the lateral edges 105a, 105b can be continuous or intermittently sealed seam edges. The edges can be bonded or sealed by bonding, heating, ultrasonic welding and / or the like or any combination thereof.

[0227] Specific exemplary separator can be processed into hybrid envelope. Hybrid envelope can be provided by forming one or more slits or openings before, during or after folding the separator sheet and bonding the edges of the separator sheet together to form the envelope. The length of the opening can be at least 1 / 50, 1 / 25, 1 / 20, 1 / 15, 1 / 10, 1 / 8, 1 / 5, 1 / 4 or 1 / 3 of the entire edge length. The length of the opening can be 1 / 50 to 1 / 3, 1 / 25 to 1 / 3, 1 / 20 to 1 / 3, 1 / 20 to 1 / 4, 1 / 15 to 1 / 4, 1 / 15 to 1 / 5 or 1 / 10 to 1 / 5 of the entire edge length. The hybrid envelope can have 1-5, 1-4, 2-4, 2-3 or 2 openings, which can be evenly or unevenly arranged along the length of the bottom edge. It is preferred that there is no opening at the envelope corner. The slits may be cut after the separator is folded and sealed to create the envelope, or they may be formed prior to forming the porous membrane into the envelope.

[0228] Some other exemplary embodiments of separator assembly construction include: positive facing ribs 104, negative facing ribs 104, negative or positive electrode envelopes, negative or positive electrode sleeves, negative or positive electrode sleeves, negative or positive electrode hybrid envelopes, two electrodes that can be encapsulated or jacketed, and combinations thereof.

[0229] In some embodiments, exemplary porous membranes can be prepared by mixing components in an extruder. For example, about 30wt% of filler and about 10wt% of UHMWPE and about 60% of process oil can be mixed in an extruder. Exemplary porous membranes can be made by passing components through a heated extruder, passing the extrudate produced by the extruder through a die head and entering the nip formed by two heated presses or calenders or rollers to form a continuous web. A large amount of process oil in the web can be extracted by using a solvent, and then the solvent is removed by drying. Afterwards, the web can be cut into bands of a predetermined width and wound onto a roller. In addition, various groove patterns can be engraved on a press or calender roller to impart ribs, grooves, textured areas, projections and / or the like as fully described herein.

[0230] In some embodiments, exemplary porous membranes can be prepared by mixing components in an extruder. For example, about 5-15wt% of a polymer (e.g., polyethylene), about 10-75wt% of a filler (e.g., silica), about 5-25wt% of a nucleating additive, and about 10-85% of a processing oil can be mixed in an extruder. Exemplary porous membranes can be manufactured by passing components through a heated extruder, passing the extrudate produced by the extruder through a die head and entering the nip formed by two heated presses or calenders or rollers to form a continuous web. A large amount of processing oil in the web can be extracted using a solvent. Afterwards, the web can be dried and cut into a band of a predetermined width, which is then wound onto a roller. In addition, various groove patterns can be engraved on a press or calender roller to impart ribs, grooves, textured areas, projections, and / or the like as fully described herein. The amounts of rubber, filler, oil, and polymer are all balanced for runnability and desired separator properties such as electrical resistance, basis weight, puncture resistance, flexural stiffness, oxidation resistance, porosity, physical strength, pore tortuosity, etc.

[0231] In a particular embodiment, performance enhancing additives or agents (e.g., nucleating additives, surfactants, wetting agents, colorants, antistatic additives, antioxidants and / or the like and combinations thereof) may be mixed with other components in an extruder. The porous membrane according to the present disclosure may then be extruded into a sheet or web shape in substantially the same manner as described above and made into a finished product.

[0232] In selected embodiments, in addition to being added to or introduced into the extruder, one or more additives may be coextruded with the separator, for example as a distinct layer of the separator.

[0233] In a particular embodiment, in addition to being added or added to the extruder, one or more additives may be applied to the separator porous membrane, for example, when the separator is completed (for example, after extracting a large amount of process oil). According to a particular preferred embodiment, the additive or a solution of the additive (e.g., an aqueous solution, a slurry, etc.) is applied to one or more surfaces of the separator. This variant is particularly suitable for the application of non-thermally stable additives and additives soluble in the solvent used to extract the process oil. Particularly suitable as solvents for additives according to the present invention are low molecular weight alcohols, such as methanol and ethanol, and mixtures of these alcohols with water. The application can be carried out on one side of the separator facing the negative electrode, on one side facing the positive electrode, or on both sides. The application can also be carried out in a solvent bath simultaneously during the extraction of the pore former (e.g., process oil). In a particular selected embodiment, a portion of the performance enhancing additive (e.g., surfactant coating) added to the extruder before manufacturing the separator or the performance enhancing additive (or both) can be combined with antimony in the battery system and can make it inactive, and / or form a compound with it and / or make it fall into the mud of the battery and / or prevent it from being deposited on the negative electrode. Surfactants or additives may also be added to the electrolyte, glass mat, battery case, adhesive paper, adhesive mat, and / or the like, or combinations thereof.

[0234] In certain embodiments, the additive (e.g., nonionic surfactant, anionic surfactant, or mixture thereof) may be present in an amount of at least about 0.5 g / m 2 , 1.0g / m 2 , 1.5g / m 2 , 2.0g / m 2 , 2.5g / m 2 3.0g / m 2 3.5g / m 2 4.0g / m 2 4.5g / m 2 5.0g / m 2 5.5g / m 2 , 6.0g / m 2 , 6.5g / m 2 , 7.0g / m 2 , 7.5g / m 2 , 8.0g / m 2 , 8.5g / m 2 , 9.0g / m 2 , 9.5g / m 2 or 10.0g / m 2 or even up to about 25.0 g / m 2 The additive may be present in a density or addition amount of about 0.5-15 g / m 2 , 0.5-10g / m 2 1.0-10.0g / m2 1.5-10.0g / m 2 2.0-10.0g / m 2 2.5-10.0g / m 2 3.0-10.0g / m 2 3.5-10.0g / m 2 4.0-10.0g / m 2 4.5-10.0g / m 2 5.0-10.0g / m 2 5.5-10.0g / m 2 , 6.0-10.0g / m 2 , 6.5-10.0g / m 2 , 7.0-10.0g / m 2 , 7.5-10.0g / m 2 4.5-7.5g / m 2 5.0-10.5g / m 2 , 5.0-11.0g / m 2 , 5.0-12.0g / m 2 , 5.0-15.0g / m 2 5.0-16.0g / m 2 5.0-17.0g / m 2 5.0-18.0g / m 2 5.0-19.0g / m 2 , 5.0-20.0g / m 2 , 5.0-21.0g / m 2 , 5.0-22.0g / m 2 , 5.0-23.0g / m 2 , 5.0-24.0g / m 2 or about 5.0-25.0g / m 2 The density or addition between them exists on the separator.

[0235] Application can also be carried out by immersing the battery separator in the additive or additive solution (solvent bath addition) and removing the solvent if necessary (e.g., by drying). In this way, the application of the additive can be combined, for example, with the extraction often used during membrane production. Other preferred methods are spraying the additive on the surface, dip-coating, roller-coating or curtain-coating one or more additives on the surface of the separator.

[0236] Additives may also be impregnated into the separator either before or after process oil extraction.

[0237] In the specific embodiments described herein, reduced amounts of ionic, cationic, anionic and / or nonionic surfactants are added to the separators of the present invention. In this case, the desired characteristics may include reduced total organic carbon and / or reduced volatile organic compounds (due to the lower amount of surfactant), and the desired separators of the present invention may be produced according to this embodiment.

[0238] In some embodiments, exemplary porous membranes can be prepared by mixing components in an extruder. For example, about 5-15wt% of a polymer (e.g., polyethylene), about 10-75wt% of a filler (e.g., silica), about 1-50wt% of a rubber and / or latex, and about 10-85% of a processing oil can be mixed in an extruder. Exemplary porous membranes can be made by passing components through a heated extruder, making the extrudate produced by the extruder pass through a die head and enter a nip formed by two heated presses or calenders or rollers to form a continuous web. Available solvents can extract a large amount of processing oil in the web. Afterwards, the web can be dried and cut into a band of a predetermined width, which is then wound onto a roller. In addition, presses or calender rollers can be engraved with various groove patterns to impart ribs, grooves, textured areas, projections, and / or the like as fully described herein. The amounts of rubber, filler, oil, and polymer are all balanced for runnability and desired separator properties such as electrical resistance, basis weight, puncture resistance, flexural stiffness, oxidation resistance, porosity, physical strength, flexure, etc.

[0239] In addition to the components added to the extruder, specific embodiments combine the rubber with the porous membrane after extrusion. For example, the rubber can be coated on one or both sides, preferably on the side facing the negative electrode, with a liquid slurry containing rubber and / or latex, optional silica and water, and then dried to form a film of this material on the surface of the exemplary porous membrane. In order to make this layer have better wettability, a wetting agent known for lead-acid batteries can be added to the slurry.

[0240] In a specific embodiment, the slurry may also contain one or more performance enhancing additives as described herein. After drying, a porous layer and / or film is formed on the surface of the separator, which adheres very well to the porous film and only increases the resistance insignificantly even if there is any. After adding the rubber, a machine press or calender or roller can be used to further press it. Other possible methods of applying rubber and / or latex are to apply the rubber and / or latex slurry to one or more surfaces of the separator by dip coating, roller coating, spray coating or curtain coating or any combination thereof. These processes may occur before or after the extraction of the process oil, or before or after it is cut into strips.

[0241] A further embodiment of the invention relates to depositing the rubber onto the membrane by dipping and drying.

[0242] In certain embodiments, an exemplary separator according to the present disclosure may be combined (laminated or otherwise) with another layer, such as a fiber layer or fiber mat having enhanced wicking properties and / or enhanced electrolyte wettability or retention properties. The fiber mat may be woven, non-woven, fleece, mesh, net-like, single-layer, multi-layer (where each layer may have the same, similar, or different characteristics as the other layers), composed of synthetic fibers or glass fibers or synthetic fibers made from a blend of glass and synthetic fibers or paper, fleece or fiber fabrics, or any combination thereof. The fiber layer or fiber mat may also contain a nucleating additive.

[0243] In certain embodiments, a fiber mat (laminated or otherwise) may be used as a carrier for an additive material. The additive material may include, for example, rubber and / or latex, optional silica, water, and / or one or more performance enhancing additives, such as the various additives described herein (including nucleating additives as described herein), or any combination thereof. For example, the additive material may be provided in the form of a slurry, which may then be coated onto one or more surfaces of the fiber mat to form a film, or may be immersed and impregnated into the fiber mat.

[0244] When there is a fiber layer, it is preferred that the porous membrane has a larger surface area than the fiber layer. Thus, when the porous membrane and the fiber layer are combined, the fiber layer does not completely cover the porous layer. Preferably, at least two opposing edge regions of the membrane layer remain uncovered to provide edges for heat sealing, which facilitates optional formation of bags or envelopes, etc. Such a fiber mat may have a thickness of at least 100 μm, in some embodiments, at least about 200 μm, at least about 250 μm, at least about 300 μm, at least about 400 μm, at least about 500 μm, at least about 600 μm, at least about 700 μm, at least about 800 μm, at least about 900 μm, at least about 1 mm, at least about 2 mm, etc. The laminated separator may then be cut into sheets. In a particular embodiment, the fiber mat is laminated to the ribbed surface of the porous membrane. In a particular embodiment, the improved separator described herein provides advantages in handling and / or assembly for battery manufacturers because it can be supplied in roll form and / or cut pieces. And as previously mentioned, the improved separator may be a stand-alone separator sheet or layer without the addition of one or more fiber mats or the like.

[0245] If the fiber mat is laminated to the porous membrane, they can be bonded together by bonding, heating, ultrasonic welding, pressing and / or the like or any combination thereof. Also, the fiber mat can be a PAM or NAM retention mat.

[0246] Example

[0247] To measure the charge acceptance, the battery cells were discharged for 20 hours and then recharged. During charging, the dynamic charge acceptance (A / Ah) was measured at the first second of charge and at the sixtieth second of charge and at various states of charge (%).

[0248] Each cell tested was a 2.5 Ah AMCO cell with a Pb grid containing 2.5% antimony (Sb). The control cell used a typical commercially available carbon-free separator except that it had a thickness of about 10 μm and a carbon content of about 0.35 mg / cm 2 The acetylene black cells used separators substantially similar to the control cells, except for the acetylene black coated separator having a coating weight distribution of 1.1 wt % to 5 wt % of an acrylic binder.

[0249] The above values ​​are for exemplary purposes only. The coating thickness may be, for example, about 5 μm to about 60 μm thick. The coating weight distribution may be, for example, about 0.1 mg / cm 2 To about 0.5mg / cm 2 Additionally, the coating may have, for example, from about 0.5 wt % to about 15 wt % of an acrylic binder.

[0250] Table 1 and Fig. 9A The values ​​measured at 1 second in this test are recorded. Table 2 and Fig. 9B The value measured at 60 seconds in this test is recorded. It can be seen that the battery using the acetylene black coated separator exhibits significantly better charge acceptance than the control battery using a commercially available separator without carbon. This specification is a theoretically possible expected battery performance according to at least one embodiment.

[0251] Table 2

[0252]

[0253] Table 3

[0254]

[0255] NH form factor example (18 positive ribs, no negative ribs): see Fig.6D .

[0256] Preferred profiles may also include negative side ribs (such as longitudinal or transverse negative micro-ribs), may have acid blended positive ribs (such as RipTide or serrated ribs), and / or combinations thereof.

[0257] Selected embodiments of the present invention provide a lead-acid battery separator having a porous membrane and a nucleating additive. The porous membrane can be selected from polyolefins, polyethylene, polypropylene, rubber, polyvinyl chloride, phenolic resins, cellulose, synthetic wood pulp, glass fiber, synthetic fiber, natural rubber, synthetic rubber, latex, bisphenol formaldehyde, and combinations thereof. If the separator is polyethylene, it can be ultra-high molecular weight polyethylene (UHMWPE).

[0258] The nucleating additive may be conductive. The nucleating additive may further be in the form of carbon and / or barium sulfate. The carbon may be in the form of conductive carbon, graphite, artificial graphite, activated carbon, carbon paper, acetylene black, carbon black, high surface area carbon black, graphene, high surface area graphene, keitjen black, carbon fiber, carbon filament, carbon nanotube, open cell carbon foam, carbon buckminster fullerene, aqueous carbon suspension, and combinations thereof. The nucleating additive may be within the porous membrane and / or on one or more surfaces of the porous membrane.

[0259] The nucleating additive can be applied to the porous membrane by a variety of methods, such as by any of the following methods: roller coating, chemical vapor deposition, coextrusion, controlled charring of the surface, controlled charring of the surface by plasma exposure, controlled charring of the surface by ultraviolet irradiation, toner printing, inkjet printing, flexographic printing, lithographic printing, slurry coating, spraying aqueous carbon suspension, impregnation, and combinations thereof.

[0260] In selected embodiments, the lead-acid battery separator may be an AGM separator.

[0261] In other exemplary embodiments, the porous membrane may contain a particulate filler and a processing plasticizer. Carbon may be further located on the surface of the separator together with a certain amount of particulate filler. The particulate filler may be any one of the following: dry finely divided silica, precipitated silica, amorphous silica, alumina, talc, or a combination thereof.

[0262] In particular embodiments, the processing plasticizer can be any of the following: processing oil, paraffinic mineral oil, mineral oil, or a combination thereof.

[0263] In selected embodiments, the porous membrane may be configured with a performance enhancing additive, which may be any of the following: a nonionic surfactant, an ionic surfactant, an anionic surfactant, a wetting agent, a colorant, an antistatic additive, a UV protection additive, an antioxidant, or a combination thereof.

[0264] In certain exemplary embodiments, the porous membrane may be configured with any of the following: solid ribs, discrete intermittent ribs, continuous ribs, discontinuous ribs, angled ribs, linear ribs, longitudinal ribs extending substantially along the machine direction of the porous membrane, transverse ribs extending substantially along the cross-machine direction of the porous membrane, transverse ribs extending substantially along the cross-machine direction of the separator, serrated protrusions or serrated ribs, stacked protrusions or stacked ribs, curved or sinusoidal ribs, ribs arranged in a solid or intermittent zigzag manner, grooves, grooves, textured areas, protrusions, depressions, porous, non-porous, micro-ribs, intersecting micro-ribs, and combinations thereof.

[0265] Another exemplary embodiment of the present invention provides a new or improved lead-acid battery having an electrolyte, a positive electrode, a negative electrode, a separator and a nucleating additive disposed therebetween. The nucleating additive may preferably be stable in the electrolyte and may be dispersed in the electrolyte. The nucleating additive may be at least semi-conductive. In some embodiments, the separator may be configured with a nucleating additive. In addition, the nucleating additive may be any one of the following: carbon, conductive carbon, graphite, artificial graphite, activated carbon, carbon paper, acetylene black, carbon black, high surface area carbon black, graphene, high surface area graphene, keitjen black, carbon fiber, carbon filament, carbon nanotube, open-cell carbon foam, carbon buckminster fullerene, aqueous carbon suspension, barium sulfate, and combinations thereof.

[0266] In certain embodiments, the nucleating additive may be on the surface of one or more separators and may be adjacent to the negative electrode. Additionally, the nucleating additive may be within the separator.

[0267] In selected embodiments of the present invention, the nucleating additive may be applied to the surface of the separator by any of the following methods: roller coating, chemical vapor deposition, coextrusion, controlled burning of the surface, controlled burning of the surface by plasma exposure, controlled burning of the surface by ultraviolet irradiation, toner printing, inkjet printing, flexographic printing, lithographic printing, slurry coating, spraying of aqueous carbon suspension, and combinations thereof. In addition, the nucleating additive may be added to any of the following: adhesive paper, base cloth (gauze), and combinations thereof.

[0268] In some exemplary embodiments, the separator may be any one of the following: polyolefin, UHMWPE, polyethylene, polypropylene, rubber, polyvinyl chloride, phenolic resin, cellulose, synthetic wood pulp, glass fiber, synthetic fiber, natural rubber, synthetic rubber, latex, bisphenol formaldehyde and combinations thereof. Other separators may be AGM separators.

[0269] The lead acid battery may be any of the following: planar battery, flooded lead acid battery, enhanced flooded lead acid battery, deep cycle battery, absorbed glass mat battery, tubular battery, inverter battery, vehicle battery, SLI battery, ISS battery, car battery, truck battery, motorcycle battery, all terrain vehicle battery, forklift battery, golf cart battery, hybrid vehicle battery, electric vehicle battery, electric rickshaw battery, electric tricycle battery and electric bicycle battery. The battery may operate in a partially charged state in motion or at rest.

[0270] In another exemplary embodiment of the present invention, a vehicle may be configured with a battery, a separator, and a nucleating additive. In some embodiments, a nucleating additive may be configured in or on the surface of the separator. In addition, the nucleating additive may be any one of the following: carbon, conductive carbon, graphite, artificial graphite, activated carbon, carbon paper, acetylene black, carbon black, high surface area carbon black, graphene, high surface area graphene, keitjen black, carbon fiber, carbon filament, carbon nanotube, open cell carbon foam, carbon buckminster fullerene, aqueous carbon suspension, barium sulfate, and combinations thereof.

[0271] In selected embodiments of the present invention, the nucleating additive can be applied to the surface of the separator by any of the following methods: roller coating, chemical vapor deposition, coextrusion, controlled burning of the surface, controlled burning of the surface by plasma exposure, controlled burning of the surface by ultraviolet irradiation, toner printing, inkjet printing, flexographic printing, lithographic printing, slurry coating, spraying of aqueous carbon suspension, and combinations thereof. In addition, the nucleating additive can be added to any of the following: adhesive paper, base cloth (gauze), and combinations thereof.

[0272] In selected embodiments, the battery can operate in a partially charged state. In other embodiments, the vehicle can be any of the following: a car, a truck, a motorcycle, an all-terrain vehicle, a forklift, a golf cart, a hybrid vehicle, an electric vehicle, an electric rickshaw, an electric tricycle, and an electric bicycle.

[0273] Disclosed or provided herein, according to at least selected embodiments, aspects, or purposes, are new or improved separators, battery separators, enhanced flooded battery separators, batteries, galvanic cells, and / or methods of making and / or using such separators, battery separators, enhanced flooded battery separators, galvanic cells, and / or batteries. According to at least specific embodiments, the present disclosure or invention is directed to new or improved battery separators for enhanced flooded batteries. In addition, disclosed herein are methods, systems, and battery separators having reduced ER, improved puncture strength, enhanced separator CMD stiffness, improved oxidation resistance, reduced separator thickness, reduced basis weight, and combinations thereof. According to at least specific embodiments, the present disclosure or invention is directed to improved separators for enhanced flooded batteries, wherein the separator has reduced ER, improved puncture strength, enhanced separator CMD stiffness, improved oxidation resistance, reduced separator thickness, reduced basis weight, or any combination thereof. According to at least certain embodiments, separators are provided that include or exhibit reduced ER, improved puncture strength, enhanced separator CMD stiffness, improved oxidation resistance, reduced separator thickness, reduced basis weight, and combinations thereof. According to at least certain embodiments, separators are provided in battery applications for use in flat-plate batteries, tubular batteries, vehicle SLI and HEV ISS applications, deep cycle applications, golf cart or golf cart and electric rickshaw batteries, batteries operating in partial state of charge (PSOC), inverter batteries, storage batteries for renewable energy, and combinations thereof.

[0274] According to at least selected embodiments, the present disclosure or invention can solve the above problems or needs. According to at least specific purposes, aspects or embodiments, the present disclosure or invention can provide improved separators and / or batteries, which overcome the above problems, for example, by providing batteries that slow down the formation of dendrites, have improved charge acceptance and / or have improved cycle performance.

[0275] Disclosed herein are improved separators for lead-acid batteries, lead-acid batteries, systems, vehicles, and / or methods and / or uses thereof. The separator may comprise a porous membrane and a nucleating additive. According to at least selected embodiments, the present disclosure or invention may address current problems or needs, and / or may provide improved separators and / or batteries that overcome current problems or difficulties, for example by providing batteries that slow dendrite formation, have increased charge acceptance, and / or have improved cycling performance.

[0276] According to at least selected embodiments, aspects or purposes, the present disclosure or invention may be directed to and / or may provide:

[0277] 1. In addition to nucleating additives, the compressive spacer shape can also reduce the size of the crystals.

[0278] 2. Can improve cycle life and discharge termination voltage: see Fig.7D .

[0279] 3. Carbon additives can be used in applications where excellent dynamic charge acceptance is the main performance requirement. Carbon additives can meet the needs of valve-regulated lead-acid batteries used in energy-saving start-stop vehicles and gate storage applications.

[0280] 4. Carbon additives can:

[0281] ◆ Reduces sulfate on negative plates ◆ Achieves excellent dynamic charge acceptance to meet the needs of multiple charge / discharge cycles ◆ Provides high life cycle under partial state of charge conditions, helping to ensure longer battery life.

[0282] 5. Possible battery applications

[0283] ◆Micro hybrid vehicles ◆Medium hybrid vehicles ◆Power ◆Energy storage system (ESS) ◆Electric bicycles

[0284] 6. In one embodiment, a possible preferred carbon additive has:

[0285] Table 4

[0286]

[0287] Without departing from the spirit of the present invention and its essential attributes, the present invention may be implemented in other forms, and therefore, when indicating the scope of the present invention, reference should be made to the appended claims rather than the foregoing description. Disclosed are components that can be used to implement the disclosed methods and systems. These and other components are disclosed herein, and it should be understood that when combinations, subsets, interactions, groups, etc. of these components are disclosed, although specific references to each different individual and collective combination and arrangement may not be explicitly disclosed, for all methods and systems, each is specifically considered and described herein. This applies to all aspects of the application, including but not limited to the steps in the disclosed methods. Therefore, if there are multiple additional steps that can be performed, it should be understood that each of these additional steps can be performed together with any specific embodiment or combination of embodiments of the disclosed method.

[0288] The written description of the foregoing structures and methods has been given for illustrative purposes only. The embodiments are used to disclose exemplary implementations, including the best mode, and also enable those skilled in the art to implement the invention, including making and using any device or system and performing any contained method. These examples are not intended to be exhaustive or limit the invention to the precise steps and / or forms disclosed, and many modifications and variations are possible according to the above teachings. The features described herein can be combined in any combination. The steps of the method described herein can be performed in any order that is physically possible. The patentable scope of the present invention is defined by the appended claims, and may include other embodiments that occur to those skilled in the art. If such other embodiments have structural elements that are not different from the literal language of the claims, or if they include equivalent structural elements that are not substantially different from the literal language of the claims, they are intended to be within the scope of the claims.

[0289] The compositions and methods of the appended claims are not limited to the specific compositions and methods described herein (which are intended to be illustrations of several aspects of the claims). Any compositions and methods that are functionally equivalent are intended to fall within the scope of the claims. Various variations of compositions and methods, in addition to those shown and described herein, are intended to fall within the scope of the appended claims. In addition, although only specific representative compositions and method steps disclosed herein are specifically described, other combinations of compositions and method steps are intended to fall within the scope of the appended claims even if not specifically described. Therefore, combinations of steps, elements, components, or ingredients may be explicitly or less explicitly mentioned herein, but other combinations of steps, elements, components, and ingredients are also included even if not explicitly stated.

[0290] When used in the specification and the appended claims, the singular forms "a", "an", and "the" include plural references unless the context clearly indicates otherwise. Ranges may be expressed herein as from "about" or "approximately" one particular value and / or to "about" or "approximately" another particular value. When such a range is expressed, another embodiment includes from a particular value and / or to another particular value. Similarly, when a value is expressed as an approximation by using the antecedent "about", it will be understood that the particular value forms another embodiment. It will be further understood that the endpoints of each range are significant relative to the other endpoint and are independent of the other endpoint. "Optional" or "optionally" means that the event or situation described subsequently may or may not occur, and the description includes situations where the event or situation occurs and situations where it does not occur.

[0291] Throughout the specification and claims of this specification, the word "comprising" and variations of the word, such as "participle form comprising" and "singular form comprising" mean "including but not limited to", and are not intended to exclude, for example, other additives, components, integers or steps. The terms "consisting essentially of" and "consisting of" may be used in place of "comprising" and "including" to provide more specific embodiments of the present invention and are also disclosed. "Exemplary" or "for example" means "an example" and is not intended to convey a preferred or ideal embodiment. Likewise, "such as" is not restrictive but is used for explanation or exemplary purposes.

[0292] Unless otherwise indicated, all numbers indicating geometric shapes, dimensions, etc. used in the specification and claims should at least be understood as not attempting to limit the application of the doctrine of equivalents to the scope of the claims and should be interpreted according to the number of significant digits and ordinary rounding techniques.

[0293] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the disclosed invention belongs.Publications cited herein and the materials for which they are cited are specifically incorporated by reference.

[0294] Furthermore, the invention illustratively disclosed herein may suitably be practiced in the absence of any element which is not specifically disclosed herein.

Claims

1. A lead-acid battery separator comprising a substrate and containing carbon; The substrate comprises a porous membrane and a base fabric, a pad and / or an adhesive paper; The carbon is disposed on at least one surface of the porous membrane, base fabric, pad and / or adhesive paper; in, The carbon has at least 1250 m 2 / g specific surface area, preferably 1250m 2 / g to 1750m 2 / g specific surface area.

2. The lead-acid battery separator according to claim 1, wherein: The porous membrane is selected from the group consisting of polyolefins, polyethylene, polypropylene, rubber, polyvinyl chloride, phenolic resin, cellulose, synthetic wood pulp, glass fiber, synthetic fiber, natural rubber, synthetic rubber, latex, bisphenol formaldehyde and combinations thereof; preferably, the polyethylene is ultra-high molecular weight polyethylene.

3. The lead-acid battery separator according to claim 1 or 2, wherein: The separator, especially the substrate, comprises a porous membrane and a base fabric; The separator, especially the substrate, comprises a porous membrane and a mat (preferably, the mat is a fiber mat; the fiber mat is woven, non-woven, braided or meshed; and / or the fibers are glass fibers, synthetic fibers or a combination of the two); and / or The separator, in particular the substrate, comprises adhesive paper.

4. The lead-acid battery separator according to claim 1, wherein: At least one surface of the substrate is further provided with: dry-process finely divided silica, precipitated silica, amorphous silica, alumina, talc, and combinations thereof; and / or The separator is an absorbed glass mat (AGM) separator.

5. A lead-acid battery comprising the lead-acid battery separator as claimed in any one of claims 1 to 4, preferably, the surface with carbon faces the negative electrode; the surface with carbon faces the positive electrode; and / or, the battery is a flooded lead-acid battery or an absorbed glass mat (AGM) battery.

6. A lead-acid battery separator comprising a porous membrane, wherein: The porous membrane contains conductive elements and / or conductive or semiconductive nucleating additives.

7. A lead-acid battery separator comprising a porous membrane, wherein: On the surface of the porous membrane, a conductive element and / or a conductive or semiconductive nucleating additive are provided.

8. The lead-acid battery separator according to claim 6 or 7, wherein: The conductive element is selected from the group consisting of carbon, conductive carbon, graphite, artificial graphite, activated carbon, carbon paper, acetylene black, carbon black, high surface area carbon black, graphene, high surface area graphene, keitjen black, carbon fiber, carbon filament, carbon nanotube, open-cell carbon foam, carbon mat, carbon felt, carbon Buckminsterfullerene [Buckminsterfullerene, Bucky Balls], aqueous carbon suspension, flake graphite, oxidized carbon, and combinations thereof.

9. An electric vehicle comprising the lead-acid battery according to claim 5.

10. A method for slowing down the formation of dendrites in a lead-acid battery separator, wherein: Inside the battery separator, Numerous nucleation sites are provided to provide starting points for crystal formation at numerous locations, thereby dispersing the total amount of lead sulfate into a large number of smaller crystals rather than a smaller number of larger crystals; thus, during the charging cycle of the lead-acid battery, these smaller crystals are more easily returned to the electrolyte, thereby hindering the growth of dendrites, improving the charge acceptance of the battery, and / or improving the cycling performance of the battery.

11. A lead-acid battery separator comprising a porous membrane, wherein: The porous membrane contains a conductive element and / or a conductive or semiconductive nucleating additive; and A conductive element and / or a conductive or semiconductive nucleation additive are coated on the surface of the porous membrane.

12. A method for improving the dynamic charging acceptance of a PSoC battery, wherein: On the outside of the battery separator, Minimizing the total contact area between the separator's toothed rib array and adjacent electrodes, but maximizing the number of discrete contact points; The teeth of the separator ribs are spaced 2.5 mm to 6.0 mm from the nearest adjacent teeth, with adjacent rows of teeth offset completely out of phase with each other; and By starting and stopping the vehicle and accelerating and decelerating, the battery electrolyte is shaken, thereby maximizing acid mixing to reduce acid stratification.

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