Improved lead-acid battery separator incorporating carbon

Abstract

An improved separator is provided that improves cycle life, reduces acid stratification, and / or reduces dendrite formation. [Solution] A lead-acid battery separator includes a porous membrane and / or a fibrous mat, and one or more conductive elements or nucleation additives within or on the porous membrane and / or fibrous mat. The nucleation additive may be at least one of carbon and barium sulfate. The conductive elements may be 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, ketjen black, carbon fiber, carbon filament, carbon nanotubes, open-cell carbon foam, carbon mat, carbon felt, carbon buckminsterfullerene, aqueous carbon suspension, graphite flakes, oxidized carbon, and combinations thereof.

Description

[Technical Field]

[0001] According to at least selected embodiments, the present disclosure or invention relates to new or improved separators for flooded lead-acid batteries, particularly lead-acid batteries such as enhanced flooded lead-acid batteries ("EFB"), and various other lead-acid batteries such as gel batteries and absorbed glass mat ("AGM") batteries. According to at least selected embodiments, the present disclosure or invention relates to new or improved separators, battery separators, battery separators incorporating carbon, battery separators incorporating conductive carbon, EFB separators, membranes, scrims, mats, batteries, cells, systems, methods including same, vehicles using same, methods of manufacturing same, uses of same, and any combination thereof. Also disclosed herein are methods, systems, and battery separators for extending battery life, reducing battery failure, reducing water loss, improving oxidative stability, improving, maintaining, and / or lowering float current, improving end-of-charge ("EOC") current, reducing the current and / or voltage required to charge and / or fully charge a deep cycle battery, minimizing internal electrical resistance, lowering electrical resistance, increasing wettability, reducing electrolyte wet-out time, shortening battery formation time, inhibiting antimony poisoning, inhibiting acid stratification, improving acid diffusion, and / or improving uniformity in lead-acid batteries, and combinations thereof. According to at least certain embodiments, the present disclosure or invention relates to improved separators for lead-acid batteries, wherein the separator comprises rubber, latex, and / or improved performance-enhancing additives and / or coatings. According to at least certain embodiments, the disclosed separators are useful in deep cycle applications, such as in transportation vehicles such as golf carts (sometimes called golf cars), inverters, and renewable and / or alternative energy systems such as solar and wind power systems. The disclosed separators are also useful in battery systems where deep cycle and / or partial state-of-charge operation is part of the battery's use.In certain other embodiments, the disclosed separators can be used in battery systems where additives and / or alloys (antimony being a prime example) are added to the battery to extend the battery's life and / or improve the battery's performance, and / or improve the battery's deep cycle and / or partial state-of-charge operation capabilities. According to at least select embodiments, the present disclosure or invention can provide improved separators and / or batteries that can address current problems or needs and / or overcome current problems or challenges, for example, by reducing dendrite formation, improving charge acceptance, and / or providing batteries with improved cycling performance. [Background technology]

[0002] Battery separators are used to separate the positive and negative electrodes (plates) of a battery to prevent electrical shorts. Such battery separators are typically porous to allow ions to pass between the positive and negative electrodes (plates). In lead-acid batteries, such as vehicle and / or industrial batteries and / or deep-cycle batteries, the battery separator is typically a porous polyethylene separator; in some cases, such separators may include a backweb and a plurality of ribs extending from one or both sides of the backweb. See Besenhard, J.O., Editor, Handbook of Battery Materials, Wiley-VCH Verlag GmbH, Weinheim, Germany (1999), Chapter 9, pp. 245-292. Some separators for vehicle batteries are manufactured in continuous lengths, rolled, folded, and sealed along the edges to form a pouch or envelope that receives the battery electrodes. Certain separators for industrial (or traction or deep cycle storage) batteries are cut to approximately the same size as the electrode plates (segments or leaves).

[0003] Lead-acid battery electrodes are often made from lead alloys with a relatively high antimony content. Batteries operating at a partial state of charge ("PSOC") are prone to acid stratification. In this state, more acid is concentrated in the electrolyte at the bottom of the battery, and more water is concentrated in the electrolyte at the top of the battery. Lead becomes water-soluble and dissolves. However, lead precipitates in the acid, forming solid crystals. Thus, acid stratification tends to form lead sulfate (PbSO4) crystals, which form dendrites. Even in cases where acid stratification does not occur, the acid is depleted during discharge, dissolving lead, and precipitation can occur as the acid is restored during a charge cycle.

[0004] When these crystals grow to a large enough size, the dendrites can drill or burn holes in the separator, forming a conductive bridge connecting the positive and negative electrodes and thereby creating a short circuit. This can prevent voltage discharge, charge acceptance, and can even cause severe damage or render the battery non-functional, all of which compromises battery performance and lifespan. Summary of the Invention [Problem to be solved by the invention]

[0005] There remains a need for improved separators that improve cycle life, reduce acid stratification, and / or reduce dendrite formation, at least for certain applications or batteries. More specifically, there remains a need for improved separators that extend battery life, reduce battery failure, improve oxidative stability, improve, maintain, and / or lower float current, improve end-of-charge ("EOC") current, reduce the current and / or voltage required to charge and / or fully charge deep cycle batteries, minimize internal electrical resistance buildup, lower electrical resistance, inhibit antimony poisoning, inhibit acid stratification, improve acid diffusion, and / or improve homogeneity in lead-acid batteries, and improved batteries (such as those operating in a partial state of charge) comprising improved separators. [Means for solving the problem]

[0006] Details of one or more embodiments are set forth in the specification below. Other features, objects, and advantages will be apparent from the specification and claims. According to at least selected embodiments, the present disclosure or invention may address the problems or needs described above. According to at least certain objects, aspects, or embodiments, the present disclosure or invention may provide improved separators and / or batteries that overcome the aforementioned problems, for example, by reducing acid stratification, mitigating dendrite formation, and / or providing batteries with improved cycling performance.

[0007] According to at least selected embodiments, the present disclosure or invention may address the above-mentioned problems or needs. According to at least certain objects, aspects, or embodiments, the present disclosure or invention may provide improved separators and / or batteries that overcome the aforementioned problems, for example, by reducing dendrite formation, improving charge acceptance, and / or providing batteries with improved cycling performance.

[0008] According to at least select embodiments, the present disclosure or invention relates to new or improved separators, battery separators, battery separators incorporating carbon, battery separators incorporating conductive carbon, EFB separators, cells, batteries, systems, and / or methods of making and / or using such new separators, cells, and / or batteries. According to at least certain embodiments, the present disclosure or invention relates to 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 energy storage batteries, vehicle batteries, starting-lighting-ignition ("SLI") vehicle batteries, idle-start-stop ("I"). The present invention relates to new or improved battery separators for vehicle batteries, automobile batteries, truck batteries, motorcycle batteries, all-terrain vehicle batteries, forklift batteries, golf cart batteries, hybrid vehicle batteries, electric vehicle batteries, e-rickshaw batteries, e-bike batteries, and / or improved methods of making and / or using such improved separators, cells, batteries, systems, etc. Also disclosed herein are methods, systems, and battery separators for extending battery performance and life, reducing battery failure, inhibiting acid stratification, mitigating sulfation and dendrite formation, improving oxidation stability, improving, maintaining, and / or lowering float current, improving end-of-charge current, reducing the current and / or voltage required to charge and / or fully charge deep cycle batteries, minimizing internal electrical resistance, inhibiting antimony poisoning, increasing wettability, improving acid diffusion, improving lead acid battery uniformity, and / or improving cycling performance. According to at least certain embodiments, the present disclosure or invention relates to improved separators, including novel separators that reduce sulfation and dendrite formation and increase charge acceptance.

[0009] Selected embodiments of the present invention comprise a lead-acid battery separator having a porous membrane, scrim, and / or mat and a nucleating additive. The porous membrane may be selected from polyolefin, 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 may be ultra-high molecular weight polyethylene (UHMWPE).

[0010] The nucleation additive may be electrically conductive. The nucleation additive may also 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, Ketjenblack, carbon fiber, carbon filament, carbon nanotubes, open-cell carbon foam, carbon mat, carbon felt, carbon buckminsterfullerenes ("buckyballs"), aqueous carbon suspensions, and combinations thereof. The nucleation additive may be present within the porous membrane, scrim, and / or mat, or on one or more surfaces of the porous membrane, scrim, and / or mat.

[0011] The nucleating additive may be applied to the porous membrane by any of the following: roller coating, chemical vapor deposition, co-extrusion, controlled burning to carbonize its surface, controlled burning to carbonize its surface by plasma exposure, controlled burning to carbonize its surface by UV exposure, toner printing, inkjet printing, flexographic printing, lithographic printing, slurry coating, spraying of an aqueous carbon suspension, impregnation, and combinations thereof.

[0012] In select embodiments, the lead acid battery separator may be an AGM separator.

[0013] In other exemplary embodiments, the porous membrane, scrim, and / or mat may include a particulate filler and a processing plasticizer. Carbon may further be present on the surface of the separator with a quantity 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.

[0014] In certain embodiments, the processing plasticizer may be any one of the following: processing oil, paraffinic mineral oil, mineral oil, or combinations thereof.

[0015] In select embodiments, the porous membrane, scrim, and / or mat may comprise performance enhancing additives, such as the following: nonionic surfactants, ionic surfactants, anionic surfactants, The additive may be any of a surfactant, a wetting agent, a colorant, an antistatic additive, a UV protection additive, an antioxidant, or a combination thereof.

[0016] In certain exemplary embodiments, the porous membrane may comprise any one of the following: solid ribs, discrete interrupted ribs, continuous ribs, discontinuous ribs, angled ribs, straight ribs, longitudinal ribs extending substantially lengthwise of the porous membrane, transverse ribs extending substantially widthwise of the porous membrane, transverse ribs extending substantially widthwise of the separator, serrated edges or serrated ribs, battlemented or battlemented ribs, curved or folded ribs arranged in continuous or broken zigzags, grooves, channels, textured regions, embossments, dimples, porous, non-porous, mini-ribs, cross mini-ribs, and combinations thereof.

[0017] Another exemplary embodiment of the present invention provides a lead-acid battery having an electrolyte, a positive electrode, a negative electrode, and a separator disposed therebetween, and a nucleation additive. The nucleation additive may preferably be stable in the electrolyte and may be dispersed in the electrolyte. The nucleation additive may be at least semiconductive. In some embodiments, the separator may comprise the nucleation additive. Furthermore, the nucleation 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, ketjen black, carbon fiber, carbon filament, carbon nanotubes, open-cell carbon foam, carbon mat, carbon felt, carbon buckminsterfullerenes ("buckyballs"), aqueous carbon suspensions, barium sulfate, and combinations thereof.

[0018] In certain embodiments, the nucleating additive may be on the surface of the separator, adjacent to the electrode, or may be internal to the separator.

[0019] In select embodiments of the present invention, the nucleation additive may be applied to the surface of the separator by any of the following: roller coating, chemical vapor deposition, coextrusion, controlled burning to carbonize the surface, controlled burning to carbonize the surface by plasma exposure, controlled burning to carbonize the surface by UV exposure, toner printing, inkjet printing, flexographic printing, lithographic printing, slurry coating, spraying of an aqueous carbon suspension, and combinations thereof. Additionally, the nucleation additive may be incorporated into any of the following: paste paper, scrim, and combinations thereof.

[0020] In some exemplary embodiments, the separator may be any 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.

[0021] The lead acid battery may be any of the following: flat plate battery, flooded lead acid battery, reinforced flooded lead acid battery, deep cycle battery, absorbent 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, e-rickshaw battery, e-trike battery, and e-bike battery. The battery may operate in a partial state of charge, while moving or stationary.

[0022] In another exemplary embodiment of the present invention, a vehicle may include a battery, a separator, and a nucleation additive. In some embodiments, the separator may include a nucleation additive either inside or on the surface of the separator. Further, the nucleation additive may be any 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, ketjenblack, carbon fiber, carbon filament, carbon nanotubes, open cell carbon foam, carbon mat, carbon felt, carbon buckminsterfullerenes ("buckyballs"), aqueous carbon suspensions, barium sulfate, and combinations thereof.

[0023] In select embodiments of the present invention, the nucleation additive may be applied to the surface of the separator by any of the following: roller coating, chemical vapor deposition, coextrusion, controlled burning to carbonize the surface, controlled burning to carbonize the surface by plasma exposure, controlled burning to carbonize the surface by UV exposure, toner printing, inkjet printing, flexographic printing, lithographic printing, slurry coating, spraying of an aqueous carbon suspension, and combinations thereof. Additionally, the nucleation additive may be incorporated into any of the following: paste paper, scrim, and combinations thereof.

[0024] In select embodiments, the battery may operate in a partial state of charge. In other embodiments, the vehicle may 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 e-rickshaw, an e-trike, and an e-bike. [Brief explanation of the drawings]

[0025] [Figure 1A] FIG. 1A shows a typical lead-acid battery. [Figure 1B] FIG. 1B shows a typical single cell of a typical lead-acid battery. [Figure 1C] FIG. 1C illustrates acid stratification in a typical lead-acid battery, generally shown in FIG. 1B. [Figure 2A] FIG. 2A shows an exemplary battery separator located between the positive and negative electrodes found in a typical lead-acid battery. [Figure 2B] FIG. 2B shows an exemplary battery separator and expanded negative electrode active material (“NAM”) found in a typical lead-acid battery. [Figure 2C] 2C shows an exemplary embodiment of a battery separator of the present invention positioned between the positive and negative electrodes found in a typical lead-acid battery, with the negative electrode shown with an expanded NAM. [Figure 2D] FIG. 2D shows an exemplary embodiment of a rib configuration of an exemplary embodiment of a separator of the present invention. [Figure 3A] Figure 3A is an SEM image of graphite. [Figure 3B] Figure 3B is an SEM image of graphite. [Figure 3C] Figure 3C is an SEM image of graphite. [Figure 3D] Figure 3D is an SEM image of the synthetic graphite. [Figure 3E] FIG. 3E is an SEM image of acetylene black. [Figure 4A] FIG. 4A is an SEM image showing the growth of lead sulfate on a lead electrode in the presence of a carbon-coated separator. [Figure 4B] FIG. 4B is an SEM image showing the growth of lead sulfate on a lead electrode in the presence of a carbon-coated separator. [Figure 4C] FIG. 4C is an SEM image showing the growth of lead sulfate on a lead electrode in the presence of a carbon-coated separator. [Figure 5A] FIG. 5A is an SEM image showing lead sulfate growth on a separator with carbon in the extrusion mixture. [Figure 5B] FIG. 5B is an SEM image showing lead sulfate growth on a separator with carbon in the extrusion mixture. [Figure 5C] FIG. 5C is an SEM image showing lead sulfate growth on a separator with carbon in the extrusion mixture. [Figure 6A] FIG. 6A is an SEM image showing the growth of lead sulfate on a lead electrode in the presence of a separator with carbon in the extrusion mixture. [Figure 6B] FIG. 6B is an SEM image showing the growth of lead sulfate on a lead electrode in the presence of a separator with carbon in the extrusion mixture. [Figure 6C] FIG. 6C is an SEM image showing the growth of lead sulfate on a lead electrode in the presence of a separator with carbon in the extrusion mixture. [Figure 7A] FIG. 7A shows the basic physical characteristics of an exemplary battery separator of the present disclosure. [Figure 7B] FIG. 7B illustrates basic physical properties of an exemplary battery separator of the present disclosure. [Figure 7C] FIG. 7C illustrates basic physical properties of an exemplary battery separator of the present disclosure. [Figure 8A] FIG. 8A illustrates a general diagram of various rib patterns of an exemplary battery separator of the present disclosure. [Figure 8B] FIG. 8B illustrates a general diagram of various rib patterns of exemplary battery separators of the present disclosure. [Figure 8C] FIG. 8C illustrates a general diagram of various rib patterns of exemplary battery separators of the present disclosure. [Figure 8D] FIG. 8D illustrates a general diagram of various rib patterns of exemplary battery separators of the present disclosure. [Figure 8E] FIG. 8E illustrates a general diagram of various rib patterns of exemplary battery separators of the present disclosure. [Figure 9A] FIG. 9A shows the dynamic state of charge of a test cell using an acetylene black coated separator compared to a control cell with a commercial separator. [Figure 9B] FIG. 9B shows the dynamic state of charge of the test cell using the acetylene black coated separator compared to a control cell with a commercial separator. DETAILED DESCRIPTION OF THE INVENTION

[0026] According to at least selected embodiments, the present disclosure or invention may address the above-mentioned problems or needs. According to at least certain objects, aspects, or embodiments, the present disclosure or invention may provide improved separators, battery separators, battery separators incorporating carbon, battery separators incorporating conductive carbon, EFB separators, and / or batteries that overcome the aforementioned problems, for example, by reducing dendrite formation, improving charge acceptance, and / or providing batteries with improved cycling performance.

[0027] As shown in FIG. 1A, an exemplary lead-acid battery 50 is shown having a positive terminal 51 and a negative terminal 53. Inside the battery 50 is an array of alternating positive or negative plates or electrodes 52 and 54 with an exemplary separator 100 disposed therebetween. The positive and negative electrodes 52, 54 and 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 of, for example, about 1.28, with a specific gravity ranging from about 1.215 to 1.300. The positive electrode 52 is in electrical communication with the positive terminal 51, and the negative electrode 54 is in electrical communication with the negative terminal 53.

[0028] Referring to FIG. 1B, a typical cell of a typical lead-acid battery is shown. FIG. 1C shows. It should be noted that FIGS. 1A-1C are 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 a separator 100, and similarly, the negative electrode 54 is in intimate contact with the separator 100. The separator serves to separate the positive and negative electrodes 52, 54 and prevent the battery from shorting out.

[0029] Figure 1C is a schematic diagram of acid stratification, as seen in certain lead-acid batteries. Sulfuric acid is heavier than water and tends to sink to the bottom of the electrolyte, making the bottom of the electrolyte higher than optimal and the top of the electrolyte, which is primarily water, lower than optimal. When this acid stratification occurs, only the bottom of the electrodes comes into contact with the sulfuric acid, affecting both the performance and lifespan of the battery. Acid stratification can be mitigated by overcharging the battery or by continuing to charge it to or near 100% capacity. During overcharge, gas bubbles form on the electrodes and tend to rise to the surface, acting as a mixer on the electrolyte. Continuous conditions, in which the battery is in a partial state of charge ("PSoC"), do not allow this overcharge effect to occur and result in greater electrolyte stratification.

[0030] The reaction ("positive half-reaction") at the lead dioxide (PbO2) positive (+) electrode 52 supplies electrons and becomes positive. This positive half-reaction at the lead dioxide (PbO2) positive (+) electrode 52 during discharge produces lead sulfate (PbSO4) and water (H2O), as shown in Equation 1 below:

[0031] [ka]

[0032] where: PbO2 is a solid lead dioxide positive electrode 52 SO4 -2 is water soluble, 4H + is water soluble, 2e - is located on a solid lead dioxide (PbO2) positive (+) electrode 52, PbSO4 is a solid precipitate in the aqueous electrolyte 56 H2O is a liquid.

[0033] The positive half-reaction can be reversed by charging the battery 50.

[0034] The negative half-reaction at the lead (Pb) negative (-) electrode 54 ("negative half-reaction") supplies cations, The negative half-reaction during discharge produces lead sulfate (PbSO4) and anions (e-), as shown in Equation 2:

[0035] [ka]

[0036] where: Pb is a solid negative (-) electrode 54, SO4 -2 is water soluble, PbSO4 is a solid precipitate in the aqueous electrolyte 56 2e - is located on the lead (Pb) negative (-) electrode 54. The negative half-reaction can be reversed by charging the battery 50.

[0037] Collectively, these half-reactions replace the entire chemical reaction of a lead-acid battery, as shown in Equation 3 below:

[0038] [ka]

[0039] where Pb is a solid lead negative electrode 54 ·PbO2 is a solid positive (+) electrode 52, H2SO4 is the liquid in the aqueous electrolyte 56, PbSO4 is a solid precipitate in the aqueous electrolyte 56 ·H2O is the liquid in the aqueous electrolyte 56.

[0040] The entire chemical reaction can be reversed when the battery 50 is charged.

[0041] For each of the above reactions, discharging occurs as it moves from left to right, and charging occurs as it moves from right to left.

[0042] As can be seen from the overall reaction, discharging a battery produces lead sulfate (PbSO4) and water (H2O). The production of water during discharge causes acid depletion (i.e., the sulfuric acid in the electrolyte is consumed), further exacerbating the acid stratification problem described above. Furthermore, as lead (Pb) in the plates dissolves in the aqueous environment, more lead becomes available to produce lead sulfate. Because lead can reverse the reaction, some of the lead sulfate can be converted back into its components (i.e., lead (Pb), lead dioxide (PbO2), and sulfuric acid (H2SO4)) during charging and / or overcharging the battery. However, lead also precipitates in the sulfuric acid, and therefore some of the lead sulfate does not revert to its components and remains as solid lead sulfate crystals.

[0043] Deep-cycle batteries, such as those used in golf carts (also known as golf cars), forklifts, e-rickshaws, e-bikes, and idle-start-stop ("ISS") vehicles, almost always operate at a partial state of charge. Such batteries are typically discharged for 8–12 hours or more before being recharged, with the possible exception of ISS batteries. Furthermore, operators of these batteries may not overcharge them before returning them for service. ISS batteries undergo many discharge cycles and many short, intermittent charge cycles, generally rarely reaching full charge, and are never overcharged. These batteries and other similar batteries are prone to acid stratification, acid depletion, or both. These batteries (or regions within the batteries) are therefore prone to periods of high electrolyte water concentration. These batteries (or regions within the batteries) are also prone to periods of high electrolyte acid concentration. Therefore, lead in the electrodes has an opportunity to dissolve into the electrolyte and subsequently precipitate into lead sulfate crystals. Over time, with many charge / discharge cycles, the lead sulfate crystals self-assemble and form dendrites, a process known as sulfation. As these dendrites grow over time, they can short out the battery or battery cell, which can cause complete battery failure or at the very least reduce performance and shorten the battery's lifespan.

[0044] The inventors hypothesize that smaller lead sulfate crystals return to solution more easily compared to larger crystals when the battery is charged. Providing nucleation sites is believed to provide initiation points for crystals to form. Furthermore, more nucleation sites provide more places for crystals to form, and therefore the total amount of lead sulfate can be spread over a greater number of small crystals as opposed to a smaller number of larger crystals. These small crystals return to solution more easily during the battery's charging cycle, thus preventing dendrite growth. The inventors have identified various nucleation additives for the separator, such as carbon and barium sulfate (BaSO4), as exemplary means of providing these nucleation sites. These additives are discussed herein. Nuclei In addition to providing production sites, carbon may also increase the charge acceptance of the battery, increasing the capacity of the battery.

[0045] Another benefit of carbon is increased charge acceptance. One hypothesis we propose is that the highly conductive carbon particles provide an electron conduction path to the active material, thus improving active material utilization. Another hypothesis we propose is that carbon increases the capacitance of the separator, thus increasing the overall battery system.

[0046] physical properties Exemplary separators may comprise a web of porous membranes, such as microporous membranes having pores less than about 5 μm, preferably less than about 1 μm, mesoporous membranes, or macroporous membranes having pores greater than about 1 μm. The porous membranes may have pore sizes preferably ranging from submicron up to 100 μm, and in certain embodiments, from about 0.1 to about 10 μm. The porosity of the separator membranes described herein may be greater than about 50 to about 60% in certain embodiments, with certain other preferred embodiments having a porosity greater than about 65%. In certain select embodiments, the porous membrane may be flat or have ribs extending from its surface.

[0047] rib Specific objectives of the present invention include maximizing the area of ​​intimate contact between the porous membrane and the negative active material and minimizing the swelling effects of the NAM (e.g., acid starvation), while also utilizing all possible operation of the battery to maximize acid mixing to reduce the effects of acid stratification, as a means of increasing dynamic charge acceptance, both of which are problems presented by operating the battery at a partial state of charge.

[0048] The inventors have found that one way to minimize the swelling effect of the NAM is to maximize the resilience of the separator, reducing the likelihood that the NAM will flex the porous backweb into the PAM. A particular way to increase separator resilience is to increase the thickness of the porous membrane backweb. However, this also increases the separator's electrical resistance (though to the detriment of a thicker backweb), which adversely affects battery performance. The inventors have found that increasing the number of contact points between the separator and the positive electrode serves to strengthen the backweb between the contact points. Increasing the number of ribs to achieve this goal also increases the contact area between the separator and the positive electrode. Minimizing the contact area is believed to lower the separator's electrical resistance and provide more surface area for the electrode's electrolyte for the electrochemical reactions that provide battery functionality. Reducing the contact area is also believed to reduce the opportunity for dendrites to form through the separator and cause electrical shorts. The issue of dendrite formation is discussed later in this specification. A further objective is to maximize electrolyte and acid mixing in the battery during operation to minimize the effects of acid stratification. Furthermore, solid ribs do not promote acid mixing, which is an objective to reduce acid stratification.

[0049] The inventors have found that to resist or mitigate backweb buckling under the forces and pressures exerted by the expansion of the acid NAM, which leads to acid starvation, the separator can be provided with a resilience means by maximizing the number of contact points while simultaneously minimizing the contact area between the separator and adjacent electrodes, as in selected exemplary preferred embodiments. The inventors have found that another selected embodiment can provide a separator with an acid mixing means for reducing, mitigating, or reversing the acid stratification effect by maximizing the number of discrete contact points between the separator and adjacent electrodes. Another selected embodiment can provide a separator with a dendrite mitigation means for reducing or mitigating the growth of lead sulfate (PbSO4) dendrites. The inventors have found that such resilience means, acid mixing means, and dendrite mitigation means can be addressed, achieved, or at least partially addressed and / or achieved by the design of the rib structure. Accordingly, select embodiments described herein rely on rib structures to provide a resilience means, an acid mixing means, and a dendrite mitigation means to balance these parameters to achieve a desired objective, and / or to at least partially address and / or achieve a balance of these parameters and / or a desired resilience means, acid mixing means, and / or dendrite mitigation means.

[0050] FIG. 2A shows an exemplary battery separator located between the positive and negative electrodes found in a typical lead-acid battery.

[0051] FIG. 2B shows an exemplary battery separator and expanded negative electrode active material (“NAM”) found in a typical lead-acid battery.

[0052] 2C shows an exemplary embodiment of a battery separator of the present invention positioned between the positive and negative electrodes found in a typical lead-acid battery, with the negative electrode shown with an expanded NAM.

[0053] The ribs 104, 106 can be uniform sets, alternating sets, or uninterrupted, separate interrupted ribs, continuous, discontinuous, angled, straight, longitudinal ribs extending substantially in the machine direction ("MD") of the separator (i.e., from the top to the bottom of the separator in a battery), transverse ribs extending substantially in the width direction (CMD) of the separator (i.e., perpendicular to the cross direction, MD, of the separator in a battery), cross ribs extending substantially in the width direction of the separator, separate toothed or serrated ribs, serrated edges, serrated ribs, battlements or battlemented ribs, continuous or intermittent zigzag arranged curved or folded grooves, channels, textured areas, embossments, dimples, porous, non-porous, mini-ribs or cross-mini-ribs, etc., and combinations thereof. Additionally, either set of ribs 104, 106 may extend from or to the positive, negative, or both sides.

[0054] Referring to Figure 2D, the exemplary separator includes positive ribs 104 aligned substantially in the separator's machine direction MD, which are intended to contact the exemplary separator's positive electrode. The separator further includes negative ribs 106 aligned substantially in the separator's machine direction MD and substantially parallel to the positive ribs. The negative ribs are intended to contact the exemplary battery's negative electrode. While the negative ribs in this illustrated embodiment are aligned substantially in the separator's machine direction, they may alternatively be aligned substantially across the separator's width, commonly known as negative cross ribs.

[0055] Continuing with FIG. 2D, select embodiments of the separator of the present invention include an array of positive side ribs. The positive side ribs include a base portion 104a that can extend longitudinally the length of the separator. Spaced teeth, discontinuous peaks, or other protrusions 104b can then extend from the surface of the base portion such that the teeth 104b are above the support structure surface of the porous membrane backweb. Furthermore, the base portion can be wider than the teeth themselves. The positive side ribs are aligned substantially parallel to one another with a typical spacing of about 2.5 to about 6.0 mm, with a typical spacing being about 3.5 mm. The height of the positive side ribs (including the teeth and base portion) measured from the surface of the porous membrane backweb is about 10 μm to about 2.0 mm, with a typical height being about 0.5 mm. Exemplary rib teeth of adjacent ribs can be substantially aligned with one another. However, as illustrated in Figure 2D, exemplary teeth may be offset from one rib to an adjacent rib, either completely or partially out of phase with the adjacent ribs. As shown, the teeth are completely out of phase from one rib to an adjacent rib. The positive electrode rib teeth may be spaced at a separator longitudinal pitch of about 3.0 to about 6.0 mm, with a typical spacing being about 4.5 mm.

[0056] As shown in FIG. 2D, the negative electrode ribs are shown to be substantially parallel to the separator's machine direction. However, they may instead be substantially parallel to the width direction. The exemplary negative electrode ribs shown are shown to be continuous and substantially straight. However, they may instead be toothed in a manner generally similar to the positive electrode ribs shown in FIG. 2D. The negative electrode ribs may be spaced at a pitch of about 10 μm to about 10.0 mm, preferably about 700 to about 800 μm, and more preferably typically about 740 μm. The height of the negative electrode ribs, as measured from the surface of the backweb, may be about 10 μm to about 2.0 mm.

[0057] It should be noted that the positive ribs may alternatively be positioned in the exemplary battery so that they contact the negative electrode. Similarly, the negative ribs may alternatively be positioned in the exemplary battery so that they contact the positive electrode.

[0058] Table 1 below shows the dimensions of 162mm x 162mm (262cm 2 ), detailing the rib count and surface contact area percentage for four separators (one exemplary inventive separator and three control separators). As shown, the exemplary inventive separator comprises 43 toothed ribs uniformly spaced widthwise across the separator width. The teeth on the positive electrode side ribs of the exemplary inventive separator are spaced apart from each other across 262 cm of the positive electrode. 2 The details of the control separators are further detailed in Table 1. Control separators #1, #2, and #3 are understood to be typical of commercially available separators currently used in flooded lead-acid batteries currently available on the market.

[0059] [Table 1]

[0060] As previously mentioned, the inventors have found that maximizing the number of contact points while simultaneously minimizing the contact area can achieve the goal of enhancing separator resilience while maintaining controlled electrical resistance. Furthermore, the toothed design facilitates acid mixing by taking advantage of the motion the battery may undergo. The separator rib teeth may be spaced from the nearest adjacent tooth by approximately 2.5 to approximately 6.0 mm. The inventors have found that a preferred, non-limiting distance is approximately 4.2 mm between adjacent teeth. Additionally, teeth offset from adjacent rows, completely out of phase, facilitate acid mixing. The inventors have also found that the backweb is sufficiently reinforced so that the base portion provides resilience against NAM expansion.

[0061] Although the exemplary inventive ribs are shown and described as being positive side ribs, they may nevertheless be provided on the negative side of the separator, and the illustrated and described negative side ribs may be provided on the positive side of the separator.

[0062] The positive electrode side or negative electrode side rib may further include a solid rib, a separate interrupted rib, a continuous rib, a discontinuous rib, an inclined rib, a straight rib, a longitudinal rib extending substantially in the longitudinal direction of the porous membrane, a transverse rib extending substantially in the width direction of the porous membrane, and a rib extending substantially in the width direction of the separator. The surface may have any shape or combination of transverse ribs, discrete ribs, toothed ribs, serrated edges, serrated ribs, battlements, battlemented ribs, curved ribs, continuous zigzag sawtooth arrangement, broken intermittent zigzag sawtooth arrangement, folded ribs, grooves, channels, textured areas, embossments, dimples, pillars, mini pillars, porous, non-porous, mini ribs, cross mini ribs, and combinations thereof.

[0063] The positive or negative ribs may also be any shape or combination defined by an angle that is neither parallel nor perpendicular to the separator edge. Furthermore, this angle may vary across the rib teeth or rows. An angled rib pattern may be a more preferred Daramic® RipTide™ acid-mixed rib shape, which may reduce or eliminate acid stratification in certain batteries. Furthermore, the angle may be defined relative to the longitudinal direction of the porous membrane, and may be greater than about zero degrees (0°) and less than about 180 degrees (180°), and greater than about 180 degrees (180°) and less than about 360 degrees (360°).

[0064] The ribs may extend uniformly across the width of the separator from side edge to side edge. This is known as a universal profile. Alternatively, the separator may have side panels adjacent to the side edges with minor ribs disposed on the side panels. These minor ribs may be more closely spaced and smaller than the primary ribs. For example, the minor ribs may be 25% to 50% of the height of the primary ribs. The side panels may alternatively be flat. The side panels may aid in sealing one edge of the separator to another edge of the separator, as occurs when enveloping the separator as discussed herein below.

[0065] In select 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 about 100%, 95%, 90%, 85%, 80%, 75%, 70%, 65%, 60%, 55%, 50%, 45%, 40%, 35%, 30%, 25%, 20%, 15%, 10%, or 5% or less of the height of the positive electrode ribs.

[0066] In some select embodiments, at least a portion of the porous membrane may include negative electrode ribs, which may be longitudinal or transverse ribs or cross ribs. The negative electrode ribs may be parallel to the upper edge of the separator or may be angled relative to the upper edge. For example, the negative electrode ribs may be oriented at approximately 0°, 5°, 15°, 25°, 30°, 45°, 60°, 70°, 80°, or 90° relative to the upper edge. The cross ribs may be oriented at approximately 0° to approximately 30°, approximately 30° to approximately 45°, approximately 45° to approximately 60°, approximately 30° to approximately 60°, approximately 30° to approximately 90°, or approximately 60° to approximately 90° relative to the upper edge.

[0067] Certain exemplary embodiments may have a base portion. If present, it may have an average base height of about 5 μm to about 200 μm. For example, the average base height may be about 5 μm or more, 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 100 μm, or 200 μm. Furthermore, if present, it may have an average base width that is about 0.0 μm to about 50 μm wider than the tooth width. For example, the average base width may be about 0.0 μm or more, 5 μm, 10 μm, 20 μm, 30 μm, 40 μm, or 50 μm wider than the tooth width.

[0068] Certain exemplary embodiments may have teeth or toothed ribs. If present, these may have an average tip length of about 50 μm to about 1.0 mm. For example, the average tip length may be greater than about 50 μm, 100 μm, 200 μm, 300 μm, 400 μm, 500 μm, 600 μm, 700 μm, 800 μm, 900 μm, 1000 μm, 1100 μm, 1200 μm, 1300 μm, 1400 μm, 1500 μm, 1600 μm, 1700 μm, 1800 μm, 1900 μm, 2000 μm, 2100 μm, 2200 μm, 2300 μm, 2400 μm, 2500 μm, 2600 μm, Alternatively, they may be 1.0 mm or less, 900 μm, 800 μm, 700 μm, 600 μm, 500 μm, 400 μm, 300 μm, 200 μm, 100 μm, or 50 μm.

[0069] At least some of the teeth or toothed ribs may have an average tooth base length of about 50 μm to about 1.0 mm. For example, the average tooth 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, they may be about 1.0 mm or less, 900 μm, 800 μm, 700 μm, 600 μm, 500 μm, 400 μm, 300 μm, 200 μm, 100 μm, or 50 μm.

[0070] At least a portion of the teeth or toothed ribs may have an average height (base height and tooth height combined) 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, they may be about 1.0 mm or less, 900 μm, 800 μm, 700 μm, 600 μm, 500 μm, 400 μm, 300 μm, 200 μm, 100 μm, or 50 μm.

[0071] At least some of the teeth or toothed ribs may have an average center-to-center pitch within a longitudinal row of about 100 μm to about 50 mm. For example, the average center-to-center pitch may be about 50 μm or more, 100 μm, 200 μm, 300 μm, 400 μm, 500 μm, 600 μm, 700 μm, 800 μm, 900 μm, or 1.0 mm, and similar increments of 50 mm or less. Alternatively, they may be about 50 μm or less, 100 μm, 200 μm, 300 μm, 400 μm, 500 μm, 600 μm, 700 μm, 800 μm, 900 μm, or 1.0 mm, and similar increments of 50 mm or less. Furthermore, adjacent rows of teeth or toothed ribs may be similarly positioned at the same or offset longitudinal positions. In an offset configuration, adjacent teeth or toothed ribs are positioned at different longitudinal positions.

[0072] At least a portion of the teeth or toothed 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 average height to base width ratio may be about 500:1.0 or less, 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.

[0073] At least a portion of the teeth or toothed ribs can have an average base width to tip width ratio of about 1,000:1.0 to about 0.1:1.0. For example, the average base width to tip width ratio can 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, 2 Alternatively, the average base width to tip width ratio may be about 1,000:1.0, 950:1.0, 900:1.0, 850:1.0, 800:1.0, 750:1.0, 700:1.0, 850:1.0, 900:1.0, 950:1.0, or 1,000:1.0. It may be 50:1.0, 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, 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.

[0074] In certain embodiments, the improved separator may include a porous membrane that may be made from one or more of a natural or synthetic substrate, a processing plasticizer, a filler, a natural or synthetic rubber or latex, a nucleation-providing additive, and / or one or more other additives and / or coatings, and the like, and combinations thereof.

[0075] In certain embodiments, exemplary natural or synthetic substrates may include polymers, thermoplastic polymers, phenolic resins, natural or synthetic rubbers, synthetic wood pulp, lignin, glass fibers, synthetic fibers, cellulosic fibers, and combinations thereof. In certain preferred embodiments, exemplary separators may be porous membranes made of thermoplastic polymers. Exemplary thermoplastic polymers may include, in principle, any acid-resistant thermoplastic material suitable for use in lead-acid batteries. In certain preferred embodiments, exemplary thermoplastic polymers may include polyvinyls and polyolefins. In certain embodiments, polyvinyls may include, for example, polyvinyl chloride ("PVC"). In certain preferred embodiments, polyolefins may include, for example, polyethylene, polypropylene, ethylene-butene copolymers, and combinations thereof, with polyethylene being preferred. In certain embodiments, exemplary natural or synthetic rubbers may include, for example, latex, non-crosslinked or crosslinked rubber, crumb or gland rubber, and combinations thereof.

[0076] In certain embodiments, the porous membrane layer preferably comprises a polyolefin, specifically polyethylene. Preferably, the polyethylene is a high molecular weight polyethylene ("HMWPE") (e.g., a polyethylene having 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, particularly greater than 4,000,000, and most preferably 5,000,000 to 8,000,000, as measured by viscometry and calculated using the Margolies equation. Furthermore, exemplary UHMWPE may have a standard load melt index of essentially zero (0), as specified and measured by ASTM D1238 (Condition E) using a standard load of 2,160 g. Additionally, exemplary UHMWPE may have a viscosity number, determined on a solution of 0.02 g of polyolefin in 100 g of decalin at 130° C., of 600 ml / g or greater, preferably 1,000 ml / g or greater, more preferably 2,000 ml / g or greater, and most preferably 3,000 ml / g or greater.

[0077] In certain embodiments, exemplary processing plasticizers may include processing oils, petroleum oils, paraffinic mineral oils, mineral oils, and combinations thereof.

[0078] The separator can contain a filler with a high structural morphology. Exemplary fillers can include silica, dry fine silica, precipitated silica, amorphous silica, highly friable 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 structural morphology refers to an increased surface area. The filler can have a surface area of, for example, about 100 m. 2 / g, approx. 110m 2 / g, approx. 120m 2 / g, approx. 130m 2 / g, approx. 140m 2 / g, approx. 150m 2 / g, approx. 160m 2 / g, approx. 170m 2 / g, approx. 180m2 / g, approx. 190m 2 / g, approx. 200m 2 / g, approx. 210m 2 / g, approx. 220m 2 / g, approx. 230m 2 / g, approx. 240m 2 / g, or approximately 250m 2 / g, some have large surface areas. In this embodiment, the filler (e.g., silica) is about 100 to 300 ml 2 / g, approx. 125~275m 2 / g, about 150~250m 2 / g, or preferably about 170-220m 2 The filler may have a surface area of ​​about 150 ml / 100 g, about 175 ml / 100 g, about 200 ml / 100 g, about 225 ml / 100 g, 250 ml / 100 g, 275 ml / 100 g, about 300 ml / 100 g, about 325 ml / 100 g, or about 350 ml / 100 g. Surface area can be assessed using a TriStar 3000™ for multi-point BET nitrogen surface area. The high structural morphology allows the filler to retain more oil during the manufacturing process. For example, a filler with high structural morphology may have a high level of oil absorption, e.g., about 150 ml / 100 g, about 175 ml / 100 g, about 200 ml / 100 g, about 225 ml / 100 g, 250 ml / 100 g, 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) can have an oil absorption of about 200-500 ml / 100g, about 200-400 ml / 100g, about 225-375 ml / 100g, about 225-350 ml / 100g, or about 225-325 ml / 100g, preferably about 250-300 ml / 100g. In some examples, a silica filler with an oil absorption of about 266 ml / 100g is used. Such a silica filler has a moisture content of about 5.1%, a BET surface area of ​​about 178 m / g, an average particle size of about 23 μm, a 230-mesh sieve retention value of about 0.1%, and a bulk density of about 135 g / L.

[0079] Silica, which has a relatively high level of oil absorption and a relatively high level of affinity for plasticizer (e.g., mineral oil), is desirably dispersible in a mixture of polyolefin (e.g., polyethylene) and plasticizer when forming an exemplary lead-acid battery separator of the type shown herein. In the past, some separators suffered from poor dispersibility due to silica agglomeration when large amounts of silica were used to make such separators or membranes. In at least some of the separators of the present invention shown and described herein, the polyolefin, such as polyethylene, forms a shish-kebab structure due to the absence of silica agglomerates that inhibit the molecular motion of the polyolefin upon cooling of the molten polyolefin. This all contributes to improved ionic permeability in the resulting separator membrane, and the formation of the shish-kebab structure or morphology means that mechanical strength is maintained, and therefore improved, while producing a separator with a lower overall ER.

[0080] In some select embodiments, the filler (e.g., silica) has an average particle size of about 25 μm or less, and in some instances about 22 μm, about 20 μm, about 18 μm, about 15 μm, or about 10 μm or less. In some examples, the average particle size of the filler particles is 15-25 μm. The particle size and / or surface area of ​​the silica filler contribute to the oil absorption of the silica filler. The silica particles in the final product, i.e., separator, can fall within the particle size ranges described above. However, the initial silica used as a raw material may occur as one or more clumps and / or agglomerates and have a size of about 200 μm or more.

[0081] 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, a silica filler that can be used with certain preferred embodiments herein may be a silica filler that has at least about 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.

[0082] The ratio (Si-OH) / Si of silanol groups (Si-OH) to elemental silicon (Si) can be measured, for example, as follows.

[0083] 1. Freeze-milling a polyolefin porous membrane (specific inventive membranes are various in accordance with the present invention) (including oil-absorbed silica), and powdered samples were analyzed by solid-state nuclear magnetic resonance spectroscopy ( 29 Si-N Prepare for MR.

[0084] 2. For powdered samples 29 Perform Si-NMR and confirm that the hydroxyl group is directly bonded to the Observe the spectrum containing Si spectral intensity (spectra: Q2 and Q3) and Si spectral intensity directly bonded only to oxygen atoms (spectra: Q4). The molecular structure of each NMR peak spectrum can be expressed as follows: Q2:(SiO)2-Si * -(OH)2: has two hydroxyl groups Q3:(SiO)3-Si * -(OH): has one hydroxyl group Q4:(SiO)4-Si * : All Si bonds are SiO where Si * is identified as an element by NMR observation

[0085] 3. Observation 29 The Si-NMR conditions were as follows: ·Equipment: Bruker BioSpin Abance 500 ·Resonance frequency: 99.36MHz Sample size: 250mg NMR tube: diameter 7m Observation method: DD / MAS Pulse width: 45 degrees Repeat time: 100 seconds Scans: 800 Magic Angle Rotation: 5,000Hz Chemical shift reference: Silicone rubber (-22.43 ppm) (external reference)

[0086] 4. Numerically separate the spectral peaks and calculate the area ratio of each peak belonging to Q2, Q3, and Q4. Then, based on these ratios, calculate the molar ratio of hydroxyl groups (-OH) directly bonded to Si. The conditions for numerical peak separation are as follows: . ·Compatible area: -80~-130ppm Initial peak top: -93 ppm in Q2, -101 ppm in Q3, -111 ppm in Q4 ppm Initial half-width: 400Hz for Q2, 350Hz for Q3, 450Hz for Q4 Gaussian function ratio: Initial 80%, during fitting 70-100%

[0087] 5. The peak area ratios of Q2, Q3, and Q4 (totaling 100) were calculated based on each peak obtained by fitting. The NMR peak areas corresponded to the number of molecules in each silicate bond structure (thus, 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 and one Si-OH bond in the silicate structure; for the Q2 NMR peak, there are three Si-O-Si bonds and one Si-OH bond in the silicate structure). There are two Si-O-Si bonds and two Si-OH bonds in the structure. Therefore, the number of hydroxyl groups (-OH) in Q2, Q3, and Q4 is set to 2, 1, and Multiply by 0. Add up these three results. The sum represents the molar ratio of hydroxyl groups (-OH) directly bonded to silicon.

[0088] In certain embodiments, the silica is 29 The molar ratio of OH groups to Si groups as measured by Si-NMR may be within 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 more.

[0089] In select embodiments, the use of the aforementioned fillers allows for a higher proportion of process oil to be used during the extrusion step. Because the separator's porous structure is partially formed by oil removal after extrusion, a higher initial oil absorption leads to a higher porosity or void volume. While process oil is an essential component of the extrusion step, the oil is a non-conductive component of the separator. Residual oil in the separator protects the separator from oxidation if it comes into contact with the positive electrode. Conventional separator manufacturing allows for control of the exact amount of oil used in the processing step. Generally speaking, conventional separators are manufactured using 50-70 wt.% process oil, 55-65 wt.% in some embodiments, 60-65 wt.% in some embodiments, and about 62 wt.% in some embodiments. Reducing the oil content below about 59% is known to increase friction against the extruder components, resulting in burning. However, significantly increasing the oil content beyond the specified amount can cause shrinkage during the drying stage, potentially leading to dimensional instability. Previous attempts to increase oil content have resulted in pore shrinkage or condensation during oil removal, but separators prepared as disclosed herein observe minimal, if any, shrinkage and condensation during oil removal. Thus, porosity can be increased without compromising pore size and dimensional stability, thereby reducing electrical resistance.

[0090] In certain select embodiments, the use of the fillers described above allows for a reduction in the final oil concentration in the finished separator. Because oil is a non-conductor, reducing the oil content can increase the ionic conductivity of the separator, helping to reduce the separator's ER. Therefore, separators with reduced final oil content can have higher efficiency. In certain select embodiments, separators are provided that have a final processing oil content of less than 20% (by weight), for example, about 14% to 20%, and in some specific embodiments, less than 19%, 18%, 17%, 16%, 15%, 14%, 13%, 12%, 11%, 10%, 9%, 8%, 7%, 6%, or 5%.

[0091] The filler can also reduce what is called the hydration sphere of electrolyte ions, enhancing ion transport through the membrane, again reducing the overall electrical resistance or ER of the battery, such as the enhanced flooded battery or system.

[0092] The one or more fillers can include various species (e.g., polar species such as metals) that facilitate the flow of electrolyte and ions through the separator, which results in a reduction in overall electrical resistance when such separators are used in flooded batteries, such as enhanced flooded batteries.

[0093] In certain embodiments, the separator may include a performance-enhancing additive in the form of a conductive element or a nucleating additive and / or a coating, which may preferably be stable in the battery's electrolyte and may even be dispersed within the electrolyte.

[0094] Exemplary forms of the conductive element and / or coating may 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, Ketjenblack, carbon fiber, carbon filament, carbon nanotubes, open-cell carbon foam, carbon mat, carbon felt, carbon buckminsterfullerenes ("buckyballs"), aqueous carbon suspensions, graphite flakes, carbon oxide, and combinations thereof. In addition to these many forms of carbon, the nucleation additive and / or coating may include barium sulfate (BaSO4) in whole or in part, either alone or in combination with carbon. One exemplary form of carbon is PBX®-135, manufactured by Cabot Corporation of Boston, MA, USA. One exemplary preferred form of carbon is PBX®-51, manufactured by Cabot Corporation of Boston, MA, USA. The inventors have determined that the greater the surface area of ​​carbon, the greater the surface area of ​​the nucleation additive and / or coating. It is theoretically assumed that the dynamic charge acceptance of the battery will increase. For example, the PBX®-51 has a capacity of at least about 1,300 to about 1,500 m. 2 / g, and Ketjenblack has a specific surface area of ​​at least about 1,250 m 2 / g specific surface area.

[0095] The nucleation coating may be applied to the finished separator by methods such as slurry coating, slot die coating, spray coating, curtain coating, inkjet printing, screen printing, or vacuum deposition, chemical vapor deposition ("CVD"), etc. Additionally, the additive and / or coating may be provided as a carbon paper, either woven or nonwoven, and may be dispersed or adhered between the separator and the electrode.

[0096] The nucleating additive and / or coating may be present within the separator, or on one or both surfaces of the separator facing the electrode. Typically, the nucleating additive coating or layer will only be present on the surface facing the negative electrode. However, it may also be present on the surface facing the positive electrode, or on both surfaces.

[0097] In certain embodiments, the nucleating additive can be added to the substrate extrusion mixture and extruded with the separator or coextruded as a layer of the separator. When included in the extrusion mixture, the nucleating additive can replace a portion of the silica filler by 5 to 75% 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 can be about 75%, 70%, 65%, 60%, 55%, 50%, 45%, 40%, 35%, 30%, 25%, 20%, 15%, 10%, or about 5% or less by weight.

[0098] Figures 3A-3C are scanning electron microscope ("SEM") images of graphite 100. Figure 3D is an SEM image of synthetic graphite. Figure 3E is an SEM image of acetylene black. These images were taken at 1,000x zoom. As can be seen, graphite 100 and synthetic graphite appear to have similar structures, with similar surface roughness and surface area for lead sulfate nucleation. However, acetylene black has a significantly rougher surface, which may provide a larger surface area for lead sulfate nucleation and more nucleation sites.

[0099] Figures 4A-4C are SEM images of lead electrodes after 100 charge / discharge cycles, showing the growth of lead sulfate crystals on the electrodes. Figures 4A and 4B are SEM images taken at 15.0 kV and 5,000x zoom. Figure 4A is a control lead electrode in the presence of optional carbon additives and / or coating separator voids. Figure 4B is an image of a lead electrode in the presence of a carbon black-coated separator. Figure 4C is an SEM image (taken at 15.0 kV and 5,500x zoom) of a lead electrode in the presence of an artificial graphite-coated separator. As can be seen, the crystals on the lead electrode are smaller in size in the presence of carbon compared to the control.

[0100] Figures 5A-5C are SEM images of lead-acid battery separators after 100 charge / discharge cycles, showing the growth of lead sulfate on the separator. These SEM images were taken at 15.0 kV and 1,000x zoom. Figure 5A is a control separator without any added carbon. Figure 5B is a separator with 5% added carbon to the extrusion mixture. Figure 5C is an image of a separator with 10% added carbon to the extrusion mixture. As shown, increasing the carbon content results in fewer and smaller lead sulfate crystals.

[0101] 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 and 10,000x magnification. The images were taken with a zoom lens. Figure 6A is an SEM image of a control lead electrode in the presence of a carbon additive and / or coating separator voids. Figure 6B is an SEM image of a lead electrode in the presence of a separator with 5% carbon added to the extrusion mixture. Figure 6C is an SEM image of a lead electrode in the presence of a separator with 10% carbon added to the extrusion mixture. As can be seen, increasing the carbon content results in fewer and smaller lead sulfate crystals.

[0102] A conductive layer may be disposed on the exemplary battery separator 100. The conductive layer may preferably be adapted to contact the battery's positive electrode (not shown). The conductive layer may be intended to provide a new route for current to and from the positive electrode (not shown). The conductive layer may be made of any conductive material, including, but not limited to, alumina, lead, gold, antimony, arsenic, zinc, barium, beryllium, lithium, magnesium, nickel, aluminum, silver, tin, and alloys of these, or carbon fiber, graphite, carbon nanotubes, buckminsterfullerenes (or buckyballs), and combinations thereof. The carbon nanotubes or buckyballs may be dispersed in a medium with a binder and applied to the battery separator. The conductive layer may be made of any conductive material that is more corrosion-resistant than the positive electrode conductor, and thus may function as the positive electrode conductor when the positive electrode conductor's conductive capacity is degraded. The conductive layer may be a lead-based alloy having 0.8-1.17% tin and 0-0.015% or more silver. The conductive layer may be a lead-based alloy having 0.02-0.06% calcium, 0.3-3% tin, and 0.01-0.05% silver. The conductive layer may be fabricated in any form, including, but not limited to, strip, screen, foil, thread, wire, coating, or combinations thereof. The conductive layer may be any thickness, for example, about 3 μm thick. The conductive layer may be disposed on the battery separator by any means, including, but not limited to, adhesive, heat sealing, coating, etc. The conductive layer may be as described in U.S. Pat. No. 9,564,623, the entire contents of which are incorporated herein by reference.

[0103] The novel separators disclosed herein may comprise latex and / or rubber. As used herein, rubber refers to rubber, latex, natural rubber, synthetic rubber, crosslinked or uncrosslinked rubber, cured or uncured rubber, crumb or ground rubber, or mixtures thereof. Exemplary natural rubbers may include one or more polyisoprene blends commercially available from various suppliers. Exemplary synthetic rubbers include methyl rubber, polybutadiene, chloroprene rubber, butyl rubber, bromobutyl rubber, polyurethane rubber, epichlorohydrin rubber, polysulfide rubber, chlorosulfonyl polyethylene, polynorbornene rubber, acrylic rubber, fluororubber, and silicone rubber, as well as 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 crosslinked or uncrosslinked; in certain preferred embodiments, the rubber is uncrosslinked. In certain embodiments, the rubber may be a mixture of crosslinked and non-crosslinked rubber.

[0104] In certain embodiments, exemplary separators may include one or more performance-enhancing additives added to the separator or porous membrane. Performance-enhancing additives may be surfactants, wetting agents, colorants, antistatic additives, antimony suppression additives, UV protection additives, antioxidants, and the like, and combinations thereof. In certain embodiments, the added surfactant may be an ionic, cationic, anionic, or nonionic surfactant.

[0105] In certain embodiments described herein, small amounts of anionic or nonionic surfactants are added to the porous membranes or separators of the present invention. The desired characteristics may include lower total organic carbon ("TOC") and / or lower volatile organic compounds ("VOCs").

[0106] Certain suitable surfactants are nonionic, while other suitable surfactants are anionic. The additive may 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. Certain suitable surfactants may have an HLB value of less than 6, preferably less than 3. The use of these certain suitable surfactants in conjunction with the separators of the present invention described herein can result in improved separators that, when used in lead-acid batteries, reduce water loss, inhibit antimony poisoning, improve cycling, reduce float current, reduce float potential, or any combination thereof. Suitable surfactants include alkyl sulfates, alkylaryl sulfonate salts, alkylphenol-alkylene oxide adducts, soaps, alkyl naphthalenes, and the like. The additives include surfactants such as one or more sulfosuccinates, such as carboxylic acid sulfonates, 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 di-alkyl phosphate esters. The 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, organosilicon surfactants, ethylene vinyl acetate terpolymers, ethoxylated alkylaryl phosphate esters, and sucrose fatty acid esters.

[0107] In certain embodiments, the additive can be represented by a compound of formula (I).

[0108] [ka]

[0109] where: 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 an oxygen atom, ·R 1 is H, -(CH2) k COOM 1 / X X+ , or -(CH2) k -SO3M 1 / X X+ , preferably H, where k=1 or 2; M is an alkali metal or alkaline earth metal ion, H + or NH4 + , where all variables M are simultaneously H + It does not have the meaning of n=0 or 1, m = 0 or an integer between 10 and 1400; x=1 or 2.

[0110] The ratio of oxygen atoms to carbon atoms in the compounds according to formula (I) ranges from 1:1.5 to 1:30, and m and n cannot simultaneously be 0. However, preferably, only one of the variables n and m is not 0.

[0111] By non-aromatic hydrocarbon radical is meant a group that does not contain or represent an aromatic group. The hydrocarbon radical may be interrupted by an oxygen atom (i.e., contains one or more ether groups).

[0112] R is preferably a linear or branched aliphatic hydrocarbon radical, which may be interrupted by an oxygen atom. Saturated, non-bridged hydrocarbon radicals are very particularly preferred. However, as noted above, R may contain an aromatic ring in certain embodiments.

[0113] By using the compound of formula (I) in the preparation of a battery separator, the separator can be effectively protected from oxidative breakdown.

[0114] Preferred is a battery separator comprising a compound according to formula (I), wherein: 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 hydrocarbon radical of the formula R-[(OCH) p (OC3H6) q ]-, where: ○R 2 is an alkyl radical having 10 to 30 carbon atoms, preferably 12 to 25, particularly preferably 14 to 20 carbon atoms, and R 2 may be linear or non-linear, such as containing an aromatic ring, P is an integer of 0 to 30, preferably 0 to 10, particularly preferably 0 to 4, q is an integer of 0 to 30, preferably 0 to 10, particularly preferably 0 to 4, Particularly preferred compounds are those in which the sum of p and q is 0 to 10, particularly 0 to 4, n=1, ·m=0.

[0115] formula R 2 -[(OC2H4) p (OC3H6) q It should be understood that ]- also includes compounds in which the arrangement of the groups in the brackets differs from that shown. For example, compounds in which the radical in brackets is formed by substituting an (OC2H4) group with an (OC3H6) group are also suitable according to the present invention.

[0116] R 2 Additives in which is a linear or branched alkyl radical having 10 to 20, preferably 14 to 18, carbon atoms have proven to be particularly advantageous. OC2H4 preferably represents OCH2CH2 and OC3H6 represents OCH(CH3)2 and / or OCH2CH2CH3.

[0117] As a preferred additive, mention may be made in particular of alcohols (p=q=0, m=0). Primary alcohols are particularly preferred, and fatty alcohol ethoxylates (p=1-4, q=0), fatty alcohol propoxylates (p=0, q=1-4), and fatty alcohol alkoxylates (p=1-2, q=1-4) are preferred. Fatty alcohol alkoxylates are available, for example, by reacting the corresponding alcohol with ethylene oxide or propylene oxide.

[0118] Additives of the type m=0 which are insoluble or only sparingly soluble in water and sulfuric acid have proven to be particularly advantageous.

[0119] Also preferred are additives comprising a compound according to formula (I), wherein R is an alkane radical having 20 to 4200, preferably 50 to 750 and very particularly preferably 80 to 225 carbon atoms, M is an alkali metal or alkaline earth metal ion, H + or NH4 + , especially Li + , Na + and K. + Alkali metal ions such as H + and all variables M are simultaneously H + does not have the meaning of n=0, m is an integer between 10 and 1400, x=1 or 2.

[0120] In certain embodiments, suitable additives may include, among others, polyacrylic acid, polymethacrylic acid, and acrylic acid-methacrylic acid copolymers, the acid groups of which are preferably 40 %, particularly preferably 80%, and is at least partially neutralized. The percentage refers to the number of acid groups. Very particularly preferred is poly(meth)acrylic acid, which exists entirely 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 poly(acrylic acid), poly(meth)acrylic acid, and acrylic acid-methacrylic acid copolymers. Poly(meth)acrylic acid, especially Preferred are polyacrylic acids having an average molar mass Mw 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. The molecular weight of poly(meth)acrylic acid polymers and copolymers is determined by measuring the viscosity of a 1% aqueous solution of the polymer neutralized with sodium hydroxide solution (Fikentscher's constant).

[0121] Copolymers of (meth)acrylic acid are also suitable, especially those containing, in addition to (meth)acrylic acid, ethylene, maleic acid, methyl acrylate, ethyl acrylate, butyl acrylate, and / or ethylhexyl acrylate as comonomers. Preference is given to copolymers containing at least 40% by weight, preferably at least 80% by weight, of (meth)acrylic acid monomer, the proportions being based on the acid form of the monomer or polymer.

[0122] Alkali metal and alkaline earth metal hydroxides, such as potassium hydroxide and especially sodium hydroxide, are particularly suitable for neutralizing polyacrylic acid polymers and copolymers. Coatings and / or additives to strengthen the separator may also include, for example, metal alkoxides, by way of example only (and not by way of limitation), where the metal may be Zn, Na, or Al, by way of example only, sodium ethoxide.

[0123] In some embodiments, the porous polyolefin membrane may include a coating on one or both sides of such a layer. Such coatings may include surfactants or other materials. In some embodiments, the coating may include one or more materials described, for example, in U.S. Pat. No. 9,876,209, which is incorporated herein by reference. Such coatings may reduce grid corrosion, extend battery life, and prevent dryout and / or water loss, for example, by reducing the overcharge voltage of the battery system.

[0124] In certain select embodiments, the membrane may be made by combining about 5-15 wt% polymer, in some instances about 10 wt% polymer (e.g., polyethylene), about 10-75 wt% filler (e.g., silica), in some instances about 30 wt% filler, and about 10-85 wt% processing oil, in some instances about 60 wt% processing oil. In other embodiments, the filler content is reduced and the oil content is high, e.g., greater than about 61 wt%, 62 wt%, 63 wt%, 64 wt%, 65 wt%, 66 wt%, 67 wt%, 68 wt%, 69 wt%, or 70 wt%. The filler-to-polymer (by weight) ratio may be, for example, about 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 (or may be within any of these specified ranges). The filler to polymer ratio (by weight) can be from about 1.5:1 to about 6:1, in some examples from 2:1 to 6:1, from about 2:1 to 5:1, from about 2:1 to 4:1, and in some examples from about 2:1 to about 3:1. The amounts of filler, oil, and polymer are all balanced for feasibility and desired separator properties, such as electrical resistance, basis weight, puncture resistance, bending stiffness, oxidation resistance, porosity, physical strength, torsion, etc.

[0125] According to at least one embodiment, the porous membrane can include UHMWPE mixed with processing oil and precipitated silica. According to at least one embodiment, the porous membrane can include UHMWPE mixed with processing oil, additives, and precipitated silica. The mixture can also include small amounts of other additives or agents common in separator technology (e.g., surfactants, wetting agents, colorants, antistatic additives, antioxidants, etc., and combinations thereof). In a specific example, the porous polymer layer can be a homogeneous mixture of about 8-100% by volume polyolefin, about 0-40% by volume plasticizer, and about 0-92% by volume inert filler. A preferred plasticizer is petroleum. Plasticizers are useful for imparting porosity to battery separators because they are the component most easily removed from polymer-filler-plasticizer compositions by solvent extraction and solvent drying.

[0126] In certain embodiments, the porous membranes disclosed herein may comprise latex and / or rubber, which may be natural rubber, synthetic rubber, or a mixture thereof. Natural rubber may include one or more polyisoprene blends commercially available from various suppliers. Exemplary synthetic rubbers include methyl rubber, polybutadiene, chloroprene rubber, butyl rubber, bromobutyl rubber, polyurethane rubber, epichlorohydrin rubber, polysulfide rubber, chlorosulfonyl polyethylene, polynorbornene rubber, acrylic rubber, fluororubber, 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 crosslinked or non-crosslinked; in certain preferred embodiments, the rubber is non-crosslinked. In certain embodiments, the rubber may be a mixture 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 10% by weight of the final separator weight (weight of the polyolefin separator sheet or layer containing the rubber and / or latex). In certain embodiments, the rubber may be present in an amount of about 1-6%, about 3-6%, about 3%, and about 6% by weight. The porous membrane may further 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 all balanced for feasibility and desired separator properties, such as electrical resistance, basis weight, puncture resistance, bending stiffness, oxidation resistance, porosity, physical strength, torsion, etc.

[0127] Porous membranes made according to the present invention, comprising polyethylene and a filler (e.g., silica), typically have a residual oil content; in some embodiments, such residual oil content is about 0.5% up to about 40% of the total weight of the separator membrane (in some instances, about 10-40% of the total weight of the separator membrane, and in some instances, about 20-40% of the total weight). In certain select embodiments herein, some or all of the residual oil in the separator membrane may be replaced by adding a large amount of a performance-enhancing additive, such as a surfactant, a surfactant with a hydrophilic-lipophilic balance ("HLB") less than 6, or a nonionic surfactant. For example, the performance-enhancing additive, such as a surfactant or nonionic surfactant, may account for up to 0.5% of the total weight of the porous separator membrane, up to the total amount of residual oil (e.g., 20%, 30%, or even 40%), thereby partially or completely replacing the residual oil in the separator membrane.

[0128] Exemplary separators may comprise a web of porous membranes, such as microporous membranes having pores less than about 5 μm, preferably less than about 1 μm, mesoporous membranes, or macroporous membranes having pores greater than about 1 μm. The porous membranes may have pore sizes preferably ranging from submicron up to 100 μm, and in certain embodiments, from about 0.1 to about 10 μm. The porosity of the separator membranes described herein may be greater than about 50 to about 70% in certain embodiments. In certain select embodiments, the porous membranes may be flat or have a surface that is 6A-6C, the separator may be defined by various dimensions, which are described in more detail later in this specification. For example, the separator may have a backweb thickness T BACK , total thickness T TOTAL , positive electrode side rib height H POS , Positive electrode side rib base width W POSBASE , Positive electrode side rib pitch P POS , negative electrode rib height H NEG , negative electrode side rib base width (not shown), and negative electrode side rib pitch P NEG may have

[0129] 6A-6C, an exemplary separator 100 comprises a web of porous membrane 102. Separator 100 and membrane 102 have a machine direction ("MD") and a cross direction ("CMD"), a top edge 101 and a bottom edge 103 (both substantially parallel to the CMD), and side edges 105a, 105b (both substantially parallel to the MD).

[0130] Referring to FIG. 7A, separator 100 includes a positive electrode surface, so named because it faces the positive electrode (not shown) when separator 100 is placed within a battery (not shown). FIG. 7A shows the positive electrode surface of the separator. One or more sets of primary or positive electrode-side ribs 104 may be provided and extend across at least a portion of the positive electrode surface of porous membrane 102. As shown, ribs 104 are not hollow and are disposed in membrane 102 substantially longitudinally, substantially parallel to separator MD. Positive electrode-side ribs 104 are shown extending uniformly across the entire separator width W from transverse edge 105a to transverse edge 105, known as a universal profile. As shown in FIG. 7C, separator 100 has a width W, which may range from about 40 to about 170 mm in at least select embodiments, depending on the type of battery in which separator 100 is used.

[0131] Referring to FIG. 7B, separator 100 includes a negative electrode surface, so named because it faces the negative electrode (not shown) when separator 100 is placed within a battery (not shown). FIG. 7B shows the negative electrode surface of the separator. One or more sets of secondary or negative electrode ribs 106 may be provided on and extend across at least a portion of the negative electrode surface of porous membrane 102. As shown, ribs 104 are not hollow and are oriented perpendicular to positive electrode ribs 104, which are substantially parallel to separator CMD. As such, the ribs may be referred to as laterally oriented, transversely oriented, or as cross ribs, negative electrode cross ribs ("NCR" or "NCR"). Negative electrode ribs 106, however, need not be perpendicular to positive electrode ribs 104. They may be the same size, larger, smaller, have the same or different patterns, or a combination thereof.

[0132] The ribs 104, 106 may be uniform sets, alternating sets, or uninterrupted, separate, interrupted ribs, continuous, discontinuous, angled, linear, longitudinal ribs extending substantially in the MD of the separator, transverse ribs extending substantially in the width direction CMD of the separator, transverse ribs extending substantially in the CMD of the separator, cross ribs extending substantially in the width direction of the separator, serrated edges, serrated ribs, battlements or battlemented ribs, continuous or interrupted zigzag arranged curved or folded grooves, channels, textured areas, embossments, dimples, porous, non-porous, mini-ribs or cross mini-ribs, etc., and combinations thereof. Additionally, the ribs 104, 106 may extend from or to the positive, negative, or both sides.

[0133] 8A-8E, several embodiments of ribbed separators with different rib geometries are shown. The ribs shown may preferably be cathode side ribs 104. The angled rib pattern of FIGS. 8A-8C may be a more preferred Daramic® RipTide® acid blend rib geometry, which may reduce or eliminate acid stratification in certain batteries. In some embodiments, the ribs may be discrete, interrupted ribs with an orientation angle relative to the separator MD. The orientation angle may be greater than zero degrees (0°). The ribs may be less than 180 degrees (180°), or greater than 180 degrees (180°) and less than 360 degrees (360°). As further shown in Figures 8A-8C, the ribs may have one or more sets of ribs, with each set having varying orientation angles and positions on the separator. The negative electrode side may have no ribs (smooth), the same ribs, smaller ribs, longitudinal mini-ribs, cross mini-ribs (NCR), diagonal ribs, or combinations thereof.

[0134] Figure 8D shows the shape of a longitudinal sawtooth rib pattern. Figure 8E shows the shape of a diagonal offset rib pattern. The negative side may have no ribs (smooth), the same ribs, smaller ribs, longitudinal mini-ribs, cross mini-ribs or NCR, diagonal ribs, or a combination thereof.

[0135] As discussed above, the ribs may extend uniformly across the width of the separator from side edge to side edge. This is known as a universal profile. Alternatively, the separator may have side panels adjacent to the side edges with minor ribs disposed on the side panels. These minor ribs may be more closely spaced and smaller than the primary ribs. For example, the minor ribs may be 25% to 50% of the height of the primary ribs. The side panels may alternatively be flat. The side panels may aid in sealing one edge of the separator to another edge of the separator, as occurs when enveloping the separator as discussed herein below.

[0136] In selected exemplary embodiments, at least a portion of the positive electrode side rib preferably has a height of about 50 μm to about 2.0 mm (H in FIG. 7C). POS In some exemplary embodiments, the positive rib height H POS In other exemplary embodiments, the positive electrode side rib height H POS may be 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 or less.

[0137] In certain selected embodiments, the positive electrode side rib preferably has a base width (W in FIG. 6C ) of about 300 μm to about 750 μm. POSBASEIn some exemplary embodiments, the positive electrode side rib base 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 side rib base width may be about 750 μm, 700 μm, 600 μm, 500 μm, 400 μm, or about 300 μm or less.

[0138] If some of the positive electrode side ribs are substantially straight and substantially parallel to each other, they may have a spatial length or pitch of about 50 μm to about 20 mm (P in FIG. 7C). POS In some exemplary embodiments, the positive electrode rib pitch 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 electrode rib pitch is 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, 120 μm, 140 μm, 150 μm, 160 μm, 170 μm, 180 μm, 190 μm, 200 μm, 210 μm, 220 μm, 230 μm, 240 μm, 250 μm, 260 μm, 270 μm, 280 μm, 290 μm, 300 μm, 310 μm, 320 μm, 330 μm, 340 μm, 350 μm, 360 μm, 370 μm, 380 μm, 390 μm, 400 μm, 410 μm, 420 μm, 430 μm, 440 μm, 450 μm, 460 μm, 470 μm, 480 μm, 490 μm, 500 μm, 510 μm, 520 μm, 530 μm, 540 μm, 550 μm, 5 m, or about 50 μm or less.

[0139] 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 negative electrode rib height may be about 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 95%, or about 100% of the positive electrode rib height. In other exemplary embodiments, the negative electrode rib height may be about 100%, 95%, 90%, 85%, 80%, 75%, 70%, 65%, 60%, 55%, 50%, 45%, 40%, 35%, 30%, 25%, 20%, 15%, 10%, or about 5% or less of the positive electrode rib height.

[0140] In selected exemplary embodiments, at least a portion of the negative electrode rib preferably has a height of about 5 μm to about 1.0 mm (H in FIG. 7C). NEG In certain embodiments, the negative electrode rib height H NEG In other exemplary embodiments, the positive electrode rib height H NEG may be 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 or less.

[0141] In certain exemplary embodiments, at least a portion of the negative electrode ribs may preferably have a base width of about 5 μm to about 1.0 mm. For example, the negative electrode base width 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 negative electrode base width may be 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 or less.

[0142] If some of the negative electrode side ribs are substantially straight and substantially parallel to each other, they may have a spatial length or pitch of about 50 μm to about 20.0 mm (P in FIG. 7B). NEG In some exemplary embodiments, the negative electrode rib pitch 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 negative electrode rib pitch may be 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, 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 or less.

[0143] In some select embodiments, at least a portion of the porous membrane may include negative electrode ribs, which may be longitudinal or transverse ribs or cross ribs. The negative electrode ribs may be parallel to the top edge of the separator or may be angled relative to the top edge. For example, The negative electrode rib may be oriented at about 0°, 5°, 15°, 25°, 30°, 45°, 60°, 70°, 80°, or 90° relative to the upper edge. The cross ribs may be oriented at 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 upper edge.

[0144] Certain exemplary embodiments may have serrated edges or ribs. If present, these may have an average tip length of about 50 μm to about 1.0 mm. For example, the average tip 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 about 1.0 mm or more. Alternatively, they may be 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 or less.

[0145] At least a portion of the serrated edges or 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, they may be 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 or less.

[0146] At least a portion of the serrated edges or 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 1.0 mm. Alternatively, they may be 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 or less. In embodiments where the height of the serrated edges is the same as the height of the ribs, the serrated ribs may be referred to as protrusions. These ranges are relative to the overall thickness T of the separator. TOTAL , which may typically be about 1 mm to about 4 mm, and the separator's overall thickness T TOTAL The thickness may be slightly smaller (for example, typically about 0.3 mm to about 1 mm) than the separator for an automobile start / stop battery.

[0147] At least some of the serrated edges or ribs may have an average center-to-center pitch within a longitudinal row of about 100 μm to about 50 mm. For example, the average center-to-center pitch may be about 50 μm, 100 μm, 200 μm, 300 μm, 400 μm, 500 μm, 600 μm, 700 μm, 800 μm, 900 μm, or values ​​equal to or greater than 1.0 mm and equal to or less than 50 mm in similar increments. Alternatively, they may be about 50 μm, 100 μm, 200 μm, 300 μm, 400 μm, 500 μm, 600 μm, 700 μm, 800 μm, 900 μm, or values ​​equal to or less than 1.0 mm and equal to or less than 50 mm in similar increments. Furthermore, adjacent rows of serrated edges or ribs may be similarly positioned at the same or offset longitudinal positions. In an offset configuration, adjacent serrated edges or ribs are positioned at different longitudinal locations.

[0148] At least a portion of the serrated edges or 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 average height to base width ratio may be 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 or less.

[0149] At least a portion of the serrated edges or ribs can have an average base width to tip width ratio of about 1,000:1.0 to about 0.1:1.0. For example, the average base width to tip width ratio can 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 ...30:1.0, 35:1.0, 40:1.0, 45:1.0, 50:1.0, 50:1.0, 60:1.0, 65:1.0, 70:1.0, 75:1.0, 80:1.0, 85:1.0, 90:1.0, 100:1.0, 110:1.0, 120:1.0, 130:1.0, 140:1.0, 150:1.0, 160:1.0, 170:1.0, 180:1.0, 190:1.0, 200:1.0, 210:1.0, 220:1.0, 230:1.0, 240:1.0, 250:1.0, 260:1.0, 27 It may be 0:1.0, 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 is 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 , 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 or less.

[0150] In some embodiments, the porous separator membrane has a backweb thickness T of about 50 μm to about 1.0 mm. BACK For example, the back web thickness T BACK 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. BACK The thickness may be 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 or less. Certain embodiments provide very thin, flat backweb thicknesses less than 50 μm, for example, from about 10 μm to about 50 μm thick.

[0151] The separator 100 may be provided as a flat plate, one or more leaves, a wrap, a sleeve, or as an envelope or pocket separator. An exemplary envelope separator may encase the positive electrode such that the separator has two inner surfaces facing the positive electrode and two outer surfaces facing the adjacent negative electrode (a "positive electrode-encasing separator"). Alternatively, another exemplary envelope separator may encase the negative electrode such that the separator has two inner surfaces facing the negative electrode and two outer surfaces facing the adjacent positive electrode (a "negative electrode-encasing separator"). In such an envelope separator, the bottom edge 103 may be a folded or sealed crease edge. Additionally, the lateral edges 105a, 105b may be continuously or intermittently sealed seam edges. The edges may be bonded or sealed by adhesive, heat, ultrasonic welding, etc., or any combination thereof.

[0152] Certain exemplary separators can be processed to form hybrid envelopes. Hybrid envelopes can be provided by folding a separator sheet in half to form the envelope and forming one or more cuts or openings before, during, or after bonding the edges of the separator sheet together. The length of the openings 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 overall edge length. The length of the openings 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 overall edge length. Hybrid envelopes can have 1 to 5, 1 to 4, 2 to 4, 2 to 3, or 2 openings, which may or may not be evenly spaced along the length of the lower edge. The corners of the envelope are preferably free of openings. The cuts may be cut after the separator is folded and sealed to create the envelope, or the cuts may be formed prior to forming the porous membrane into the envelope.

[0153] Some other exemplary embodiments of separator assembly configurations include positive-facing ribs 104, negative-facing ribs 104, negative or positive electrode envelopes, negative or positive electrode sleeves, negative or positive electrode hybrid envelopes, both electrodes that may be wrapped or sleeved, and combinations thereof.

[0154] In some embodiments, exemplary porous membranes may be made by mixing components in an extruder. For example, about 30% by weight of filler may be mixed with about 10% by weight of UHMWPE and about 60% processing oil in an extruder. Exemplary porous membranes may be made by passing the components through a heated extruder, forcing the extrudate produced by the extruder through a die and into a nip formed by two heated press or calender stacks or rolls to form a continuous web. A solvent may be used to extract a substantial amount of the processing oil from the web, followed by drying to remove the solvent. The web may then be slit into lanes of a predetermined width and wound onto a roll. Additionally, the press or calender roll may be engraved with various groove patterns to impart ribs, grooves, textured areas, embossments, and / or other features substantially as described herein.

[0155] In some embodiments, exemplary porous membranes may be made by mixing components in an extruder. For example, about 5-15% by weight of a polymer (e.g., polyethylene), about 10-75% by weight of a filler (e.g., silica), about 5-25% by weight of a nucleating additive, and about 10-85% by weight of a processing oil may be mixed in the extruder. Exemplary porous membranes may be made by passing the components through a heated extruder, and forcing the extrudate produced by the extruder through a die and into a nip formed by two heated press or calender stacks or rolls to form a continuous web. A substantial amount of the processing oil may be extracted from the web using a solvent. The web may then be dried, slit into lanes of a predetermined width, and wound onto a roll. Additionally, the press or calender roll may be engraved with various groove patterns to impart ribs, grooves, textured areas, embossments, and / or other features substantially as described herein. The amounts of rubber, filler, oil, and polymer are all balanced for feasibility and desired separator properties, such as electrical resistance, basis weight, puncture resistance, bending stiffness, oxidation resistance, porosity, physical strength, torsion, and the like.

[0156] In certain embodiments, performance enhancing additives or agents (e.g., nucleating additives, surfactants, wetting agents, colorants, antistatic additives, antioxidants, etc., and combinations thereof) may also be mixed with other components in the extruder. Porous membranes according to the present disclosure can then be extruded into sheets or webs and finished in substantially the same manner as described above.

[0157] In select embodiments, in addition to or instead of being added to the extruder, one or more additives may be co-extruded into the separator, for example, as a separate layer of the separator.

[0158] In certain embodiments, one or more additives can be applied to the separator porous membrane as it is completed (e.g., after a large amount of processing oil has been extracted), in addition to or instead of being added in the extruder. According to certain preferred embodiments, 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 applying thermally unstable additives and additives that are soluble in the solvent used to extract the processing oil. Low molecular weight alcohols, such as methanol and ethanol, and mixtures of these alcohols with water are particularly suitable as solvents for additives according to the present invention. Application can be performed on the side facing the negative electrode, the side facing the positive electrode, or on both sides of the separator. The coating may also occur during extraction of the pore-forming agent (e.g., processing oil) in a solvent bath. In certain select embodiments, a portion of the performance-enhancing additive, such as a surfactant coating or performance-enhancing additive (or both), added to the extruder before the separator is manufactured may bind with antimony in the battery system, deactivating the antimony and / or forming compounds containing antimony, and / or causing the antimony to sink into the battery's mud pan and / or preventing antimony from precipitating on the negative electrode. The surfactant or additive may be added to the electrolyte, glass mat, battery case, paste paper, paste mat, etc., and / or combinations thereof.

[0159] In certain embodiments, the additive (e.g., a nonionic surfactant, an anionic surfactant, or a mixture thereof) is present in an amount of at least about 0.5 g / m 2 , 1.0 g / m 2 , 1.5g / m 2 , 2.0 g / m 2 , 2.5g / m 2 , 3.0 g / m 2 , 3.5g / m 2 , 4.0g / m 2 , 4.5g / m 2 , 5.0g / m 2 , 5.5g / m 2 , 6.0 g / m 2 , 6.5g / m 2 , 7.0 g / m 2 , 7.5g / m 2 , 8.0 g / m 2 , 8.5g / m 2 , 9.0 g / m 2 , 9.5g / m 2 or 10.0 g / m 2 , or even up to about 25.0 g / m 2 The additive may be present at a density or add-on level of 0.5 to 15 g / m 2 , 0.5 to 10 g / m 2 , 1.0 to 10.0 g / m 2 , 1.5 to 10.0 g / m 2 , 2.0 to 10.0 g / m 2 , 2.5 to 10.0 g / m 2 , 3.0~10.0g / m 2 , 3.5 to 10.0 g / m 2 , 4.0~10.0g / m 2 , 4.5 to 10.0 g / m 2 , 5.0~10.0g / m 2 , 5.5 to 10.0 g / m 2 , 6.0~10.0g / m 2 , 6.5 to 10.0 g / m 2 , 7.0~10.0g / m 2 , 7.5 to 10.0 g / m 2 , 4.5 to 7.5 g / m 2 , 5.0~10.5g / m 2 , 5.0~11.0g / m 2 , 5.0~12.0g / m2 , 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 approximately 5.0 to 25.0 g / m 2 density or add-on level on the separator.

[0160] Application may be performed by immersing the battery separator in the additive or a solution of the additive (solvent bath application) and removing the solvent as needed (e.g., by drying). In this manner, application of the additive may be combined with extraction, which is often applied, for example, during membrane formation. Other preferred methods are to apply one or more additives to the separator surface by spraying the additive onto the surface, dip coating, roller coating, or curtain application.

[0161] The additive may be impregnated into the separator before or after processing oil extraction.

[0162] In certain embodiments described herein, small amounts of ionic, cationic, anionic, and / or nonionic surfactants are added to the separators of the present invention. In such instances, desirable characteristics include lower amounts of total organic carbon and / or lower amounts of volatile organic compounds (due to the lower amounts of surfactants), allowing desirable separators of the present invention to be produced according to such embodiments.

[0163] In some embodiments, exemplary porous membranes may be made by mixing components in an extruder. For example, about 5-15% by weight of a polymer (e.g., polyethylene), about 10-75% by weight of a filler (e.g., silica), about 1-50% by weight of a rubber and / or latex, and about 10-85% by weight of a processing oil may be mixed in the extruder. Exemplary porous membranes may be made by passing the components through a heated extruder, forcing the extrudate produced by the extruder through a die and into a nip formed by two heated presses or calender stacks or rolls to form a continuous web. A substantial amount of the processing oil may be extracted from the web using a solvent. The web may then be dried and slit into lanes of a predetermined width. The separator may be wound onto a roll. Additionally, the press or calender rolls may be engraved with various groove patterns to impart ribs, grooves, textured areas, embossments, etc., and / or substantially as described herein. The amounts of rubber, filler, oil, and polymer are all balanced for feasibility and desired separator properties, such as electrical resistance, basis weight, puncture resistance, bending stiffness, oxidation resistance, porosity, physical strength, torsion, etc.

[0164] In addition to being added to the extruder components, certain embodiments bond the rubber to the porous membrane after extrusion. For example, the rubber may be coated on one or both sides, preferably the side facing the negative electrode, with a liquid slurry comprising rubber and / or latex, optionally silica, and water, and then dried so that a film of this material forms on the surface of the exemplary porous membrane. To improve the wettability of this layer, known wetting agents may be added to slurries used in lead-acid batteries.

[0165] In certain embodiments, the slurry can also include one or more performance-enhancing additives described herein. After drying, a porous layer and / or membrane is formed on the surface of the separator that adheres very tightly to the porous membrane and increases electrical resistance only slightly, if at all. After the rubber is added, it may be further compressed using a mechanical press or a calender stack or roll. Another possible method of applying the rubber and / or latex is to apply the rubber and / or latex slurry to one or more surfaces of the separator by dip coating, roller coating, spray coating, curtain coating, or any combination thereof. These processes may be performed before or after the process oil is extracted, or before or after it is slit into lanes.

[0166] A further embodiment of the present invention involves attaching the rubber to the membrane by impregnation and drying.

[0167] In certain embodiments, exemplary separators according to the present disclosure may be combined with another layer (laminated or otherwise), such as a fibrous layer or fibrous mat, having improved wicking properties and / or improved electrolyte wetting or retention. The fibrous mat may be a woven, nonwoven, fleece, mesh, net, single layer, multiple layers (each layer may have the same, similar, or different properties from the other layers) made from glass or synthetic fibers, a fleece or woven made from synthetic fibers, a blend of glass and synthetic fibers, or paper, or any combination thereof. The fibrous layer or fibrous mat may also include a nucleating additive.

[0168] In certain embodiments, the fibrous mat (laminated or otherwise) may be used as a carrier for additional materials. The additional materials may include, for example, rubber and / or latex, optionally silica, water, and / or one or more performance-enhancing additives such as various additives described herein, including nucleating additives described herein, or combinations thereof. By way of example, the additional materials may be provided in the form of a slurry that can then be coated onto one or more surfaces of the fibrous mat to form a film or that can penetrate and impregnate the fibrous mat.

[0169] When a fibrous layer is present, the porous membrane preferably has a larger surface area than the fibrous layer. Thus, when the porous membrane and the fibrous layer are joined, the fibrous layer does not completely cover the porous layer. Preferably, at least two opposing edge regions of the membrane layer are left uncovered to provide edges for heat sealing to facilitate the optional formation of pockets, envelopes, etc. The thickness of such a fibrous mat is, in some embodiments, at least 100 μm, 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, The thickness of the separator may be at least about 2 mm, etc. The laminated separator can then be cut into pieces. In certain embodiments, a fibrous mat is laminated to the ribbed surface of a porous membrane. In certain embodiments, the improved separator described herein provides battery manufacturers with handling and / or assembly advantages when supplied in rolls and / or cut pieces. Also, as previously mentioned, the improved separator may be a free-standing separator sheet or layer without one or more fibrous mats or the like attached.

[0170] When laminated to the porous membrane, the fibrous mat may be adhered by adhesives, heat, ultrasonic welding, compression, etc., or any combination thereof, and the fibrous mat may be a PAM or NAM bearing mat. [Example]

[0171] To measure charge acceptance, the battery cells were discharged for 20 hours and then charged. During charging, the dynamic charge acceptance (A / Ah) was measured at multiple states of charge (%) during the first second of charge and the 60th second of charge.

[0172] 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 commercial separator without carbon. The acetylene black cell had a coating thickness of approximately 10 μm and a coating weight distribution of approximately 0.35 mg / cm. 2 A separator substantially similar to the control cell was used, except that the separator incorporated acetylene black, where the acetylene black coating had about 1 to about 5 weight percent of an acrylic acid binder.

[0173] The above values ​​are used for illustrative purposes only. The coating thickness may be, for example, about 5 to about 60 μm thick. The coating weight distribution may be, for example, about 0.1 to about 0.5 mg / cm. 2 Additionally, the coating may have, for example, about 0.5 to about 15 weight percent of an acrylic acid binder.

[0174] The values ​​measured during the first second of this test are stored in Table 1 and FIG. 9A. The values ​​measured during the 60th second of this test are stored in Table 2 and FIG. 9B. As can be seen, the cell utilizing the acetylene black coated separator exhibited significantly better charge acceptance compared to the control cell utilizing a commercial separator without incorporated carbon. This specification is a theoretically possible desirable battery performance according to at least one embodiment.

[0175] [Table 2]

[0176] [Table 3]

[0177] [Table 4]

[0178] Preferred geometries may also include anode ribs (such as vertical or horizontal anode mini-ribs), acid-mixed cathode ribs (RipTide or serrated ribs), and / or combinations thereof.

[0179] Selected embodiments of the present invention include a lead-acid battery separator having a porous membrane and a nucleation additive. The porous membrane may be selected from polyolefins, polyethylene, polypropylene, rubber, polyvinyl chloride, phenolic resins, cellulose, synthetic wood pulp, glass fiber, synthetic fibers, natural rubber, synthetic rubber, latex, bisphenol formaldehyde, and combinations thereof. If the separator is polyethylene, it may be ultra-high molecular weight polyethylene (UHMWPE).

[0180] The nucleation additive may be electrically conductive. The nucleation 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, Ketjen black, carbon fiber, carbon filaments, carbon nanotubes, open-cell carbon foam, carbon buckminsterfullerene, aqueous carbon suspensions, and combinations thereof. The nucleation additive may be located within the porous membrane and / or on one or more surfaces of the porous membrane.

[0181] The nucleating additive may be applied to the porous membrane by any of a number of methods, such as roller coating, chemical vapor deposition, co-extrusion, controlled burning to carbonize its surface, controlled burning to carbonize its surface by plasma exposure, controlled burning to carbonize its surface by UV exposure, toner printing, inkjet printing, flexographic printing, lithographic printing, slurry coating, spraying of an aqueous carbon suspension, impregnation, and combinations thereof.

[0182] In select embodiments, the lead acid battery separator may be an AGM separator.

[0183] In other exemplary embodiments, the porous membrane may include a particulate filler and a processing plasticizer. The carbon may further be on the surface of the separator with a quantity 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.

[0184] In certain embodiments, the processing plasticizer may be any one of the following: processing oil, paraffinic mineral oil, mineral oil, or combinations thereof.

[0185] In select embodiments, the porous membrane may comprise performance enhancing additives, which may be any of the following: nonionic surfactants, ionic surfactants, anionic surfactants, wetting agents, colorants, antistatic additives, UV protection additives, antioxidants, etc., or combinations thereof.

[0186] In certain exemplary embodiments, the porous membrane may comprise any one of the following: solid ribs, discrete interrupted ribs, continuous ribs, discontinuous ribs, angled ribs, straight ribs, longitudinal ribs extending substantially lengthwise of the porous membrane, transverse ribs extending substantially widthwise of the porous membrane, transverse ribs extending substantially widthwise of the separator, serrated edges or serrated ribs, battlemented or battlemented ribs, curved or folded ribs arranged in continuous or broken zigzags, grooves, channels, textured regions, embossments, dimples, porous, non-porous, mini-ribs, cross mini-ribs, and combinations thereof.

[0187] Another exemplary embodiment of the present invention provides a new or improved lead-acid battery having an electrolyte, a positive electrode, a negative electrode, and a separator disposed therebetween, and a nucleation additive. The nucleation additive may preferably be stable in the electrolyte and may be dispersed in the electrolyte. The nucleation additive may be at least semiconductive. In some embodiments, the separator may comprise the nucleation additive. Furthermore, the nucleation 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, ketjen black, carbon fiber, carbon filament, carbon nanotubes, open-cell carbon foam, carbon buckminsterfullerene, aqueous carbon suspension, barium sulfate, and combinations thereof.

[0188] In certain embodiments, the nucleating additive may be on the surface of the separator, adjacent to the negative electrode, or may be internal to the separator.

[0189] In select embodiments of the present invention, the nucleation additive may be applied to the surface of the separator by any of the following: roller coating, chemical vapor deposition, coextrusion, controlled burning to carbonize the surface, controlled burning to carbonize the surface by plasma exposure, controlled burning to carbonize the surface by UV exposure, toner printing, inkjet printing, flexographic printing, lithographic printing, slurry coating, spraying of an aqueous carbon suspension, and combinations thereof. Additionally, the nucleation additive may be incorporated into any of the following: paste paper, scrim, and combinations thereof.

[0190] In some exemplary embodiments, the separator may be any 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. The separator may be an AGM separator.

[0191] The lead acid battery may be any of the following: flat plate battery, flooded lead acid battery, reinforced flooded lead acid battery, deep cycle battery, absorbent 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, e-rickshaw battery, e-trike battery, and e-bike battery. The battery may operate in a partial state of charge, while moving or stationary.

[0192] In another exemplary embodiment of the present invention, a vehicle may include a battery, a separator, and a nucleation additive. In some embodiments, the separator may include a nucleation additive either within or on the surface of the separator. Furthermore, the nucleation 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, ketjen black, carbon fiber, carbon filament, carbon nanotubes, open-cell carbon foam, carbon buckminsterfullerene, aqueous carbon suspension, barium sulfate, and combinations thereof.

[0193] In select embodiments of the present invention, the nucleation additive may be applied to the surface of the separator by any of the following: roller coating, chemical vapor deposition, coextrusion, controlled burning to carbonize the surface, controlled burning to carbonize the surface by plasma exposure, controlled burning to carbonize the surface by UV exposure, toner printing, inkjet printing, flexographic printing, lithographic printing, slurry coating, spraying of an aqueous carbon suspension, and combinations thereof. Additionally, the nucleation additive may be incorporated into any of the following: paste paper, scrim, and combinations thereof.

[0194] In select embodiments, the battery may operate in a partial state of charge. In other embodiments, the vehicle may 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 e-rickshaw, an e-trike, and an e-bike.

[0195] According to at least selected embodiments, aspects, or objectives, disclosed or provided herein are new or improved separators, battery separators, reinforced flooded battery separators, batteries, cells, and / or methods of making and / or using such separators, battery separators, reinforced flooded battery separators, cells, and / or batteries. According to at least certain embodiments, the disclosure or invention relates to new or improved battery separators for reinforced flooded batteries. Also disclosed herein are methods, systems, and battery separators having reduced ER, improved puncture strength, improved separator CMD stiffness, improved oxidation resistance, reduced separator thickness, reduced basis weight, and combinations thereof. According to at least certain embodiments, the disclosure or invention relates to improved separators for reinforced flooded batteries, the separators having reduced ER, improved puncture strength, improved 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, improved separator CMD stiffness, improved oxidation resistance, reduced separator thickness, reduced basis weight, and combinations thereof. According to at least certain embodiments, separators are provided for battery applications such as flat plate batteries, tubular batteries, vehicular SLI and HEV ISS applications, deep cycle applications, batteries for golf cars or golf carts and e-rickshaws, batteries operating at partial state of charge ("PSOC"), inverter batteries, and storage batteries for renewable energy sources, and combinations thereof.

[0196] According to at least selected embodiments, the present disclosure or invention may address the above-mentioned problems or needs. According to at least certain objects, aspects, or embodiments, the present disclosure or invention may provide improved separators and / or batteries that overcome the aforementioned problems, for example, by reducing dendrite formation, improving charge acceptance, and / or providing batteries with improved cycling performance.

[0197] Disclosed herein are improved separators for lead-acid batteries, lead-acid batteries, systems, vehicles, and / or methods and / or uses therefor. The separator may include a porous membrane and a nucleation additive. According to at least select embodiments, the present disclosure or invention may provide improved separators and / or batteries that may address current problems or needs and / or overcome current problems or challenges, for example, by reducing dendrite formation, improving charge acceptance, and / or providing batteries with improved cycling performance.

[0198] According to at least selected embodiments, aspects or objects, the present disclosure or invention may relate to and / or provide: 1. A compression resistant separator profile may reduce the size of the crystals in addition to the nucleation additive. 2. The cycle life and discharge end voltage can be improved.

[0199] [Table 5]

[0200] 3. Carbon additives can be used in applications where excellent dynamic charge acceptance is a key performance requirement. Carbon additives can address the needs of valve-regulated lead-acid batteries for fuel-efficient start-stop vehicles and grid storage applications. 4. Carbon additives reduce sulfation of the negative plate, enabling excellent dynamic charge acceptance to meet the demands of numerous charge / discharge cycles, and providing a high life cycle while helping ensure longer battery life at partial charge. 5. Possible battery applications Micro-hybrid vehicles, mild hybrid vehicles, transportation, energy storage systems (ESS), e-bikes 6. In one example, an optionally preferred carbon additive is:

[0201] [Table 6]

[0202] The present invention may be embodied in other forms without departing from the spirit and essential attributes thereof, and therefore, reference should be made to the appended claims, rather than the foregoing specification, as indicating the scope of the present invention. Components that can be used to perform the disclosed methods and systems are disclosed. These and other components are disclosed herein, and when combinations, subsets, interactions, groups, etc. of these components are disclosed, it is understood that specific reference to their various individual and collective combinations and permutations is not expressly disclosed, but each is specifically contemplated and described herein for all methods and systems. This applies to all aspects of the present application, including, but not limited to, steps in the disclosed methods. Thus, where there are various additional steps that may be performed, it is understood that each of these additional steps may be performed with any specific embodiment or combination of embodiments of the disclosed methods.

[0203] The foregoing descriptions of structures and methods have been presented for purposes of illustration only. The examples disclose exemplary embodiments, including the best mode, and also serve to enable any person skilled in the art to practice the invention, including making and using any device or system, and performing any incorporated methods. These examples are not intended to be exhaustive or to limit the invention to the precise steps and / or forms disclosed. Numerous modifications and variations are possible in light of the above teachings. The features described herein may be combined in any combination. The steps of methods described herein may be performed in any sequence that is physically possible. The patentable scope of the invention is defined by the appended claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that are the same as the claim language, or if they include equivalent structural elements that have insubstantial differences from the claim language.

[0204] The compositions and methods of the appended claims are not limited in scope by the specific compositions and methods described herein, which are intended to exemplify only a few aspects of the claims. Any compositions and methods that are functionally equivalent are intended to be within the scope of the claims. Various composition and method variations in addition to those shown and described herein are intended to be within the scope of the appended claims. Furthermore, while only certain representative compositions and method steps disclosed herein have been specifically set forth, other combinations of compositions and method steps, even if not specifically recited, are intended to be within the scope of the appended claims. Thus, although combinations of steps, elements, components, or structures are referred to herein, either explicitly or infra, other combinations of steps, elements, components, and structures are also included, even if not explicitly stated.

[0205] As used in the specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Ranges are expressed herein as ranging from "about" or "approximately" one particular value and / or from "about" or "approximately" another. Ranges may be expressed as up to a particular value. When such a range is expressed, another embodiment includes from the one particular value and / or to the other particular value. Similarly, when values ​​are expressed as approximations, by use of the term "about," it is understood that the particular value forms another embodiment. It is further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint. "Optional" or "optionally" means that the subsequently described event or circumstance may or may not occur, and that the description includes instances when the event or circumstance occurs and instances when it does not occur.

[0206] Throughout the description and claims of this specification, the word "comprise" and variations of this word, such as "comprising" and "comprises," mean "including but not limited to" and are not intended to exclude, for example, other additives, ingredients, integers, or steps. The terms "consisting essentially of" and "consisting of" can be used in place of "comprising" and "including" to provide more specific embodiments of the invention, which are also disclosed. "exemplary" or "for example" means "an example of" and is not intended to convey that a preferred or ideal embodiment is indicated. Similarly, "such as" is not intended to convey that a preferred or ideal embodiment is indicated. "as") is not used in a limiting sense, but rather for descriptive or illustrative purposes.

[0207] Except as noted, all numbers expressing shapes, dimensions, and the like used in the specification and claims should, at the very least, be construed in light of the number of significant digits and ordinary rounding approaches, and not be construed as an attempt to limit the application of the doctrine of equivalents to the scope of the claims.

[0208] Unless otherwise defined, 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.

[0209] Additionally, any invention illustratively disclosed herein suitably may be practiced in the absence of any element not specifically disclosed herein.

Claims

1. A lead-acid battery separator, the lead-acid battery separator comprising: a porous membrane and / or a fibrous mat, and one or more conductive elements or nucleating additives within or on said porous membrane and / or said fibrous mat; A lead-acid battery separator comprising:

2. 10. The lead acid battery separator of claim 1, wherein the porous membrane is selected from the group consisting of polyolefin, 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.

3. 3. The lead acid battery separator of claim 2, wherein the polyethylene is ultra-high molecular weight polyethylene.

4. 10. The lead acid battery separator of claim 1, wherein said porous membrane has a porosity of at least about 50%.

5. 10. The lead acid battery separator of claim 1, wherein the nucleating additive is electrically conductive.

6. The nucleation additives include carbon and barium sulfate (BaSO ４ 10. The lead acid battery separator of claim 1, wherein the lead acid battery separator is at least one of:

7. 2. The lead acid battery separator of claim 1, 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, Ketjenblack, carbon fiber, carbon filament, carbon nanotubes, open cell carbon foam, carbon mat, carbon felt, carbon buckminsterfullerenes ("buckyballs"), aqueous carbon suspensions, graphite flakes, oxidized carbon, and combinations thereof.

8. The conductive element has a length of at least about 1,250 to 1,750 m. ２ 10. The lead acid battery separator of claim 1, having a specific surface area of ​​0.15 wt. / g.

9. The conductive element has a length of at least about 1,750 m. ２ 10. The lead acid battery separator of claim 1, having a specific surface area of ​​0.15 wt. / g.

10. 10. The lead acid battery separator of claim 1, wherein the conductive element or nucleating additive is within or on the porous membrane or fibrous mat.

11. 10. The lead acid battery separator of claim 1, wherein the porous membrane is an AGM separator or is adjacent to an AGM separator.

12. 3. The lead acid battery separator of claim 2, wherein the porous membrane comprises a particulate filler.

13. 13. The lead acid battery separator of claim 12, wherein the conductive elements or the nucleating additive are on the surface of the porous membrane with an amount of particulate filler.

14. 14. The lead acid battery of claim 12 or 13, wherein the particulate filler is selected from the group consisting of dry finely divided silica, precipitated silica, amorphous silica, alumina, talc, and combinations thereof. Battery separator.

15. 3. The lead acid battery separator of claim 2, further comprising a performance enhancing additive selected from the group consisting of surfactants, wetting agents, colorants, antistatic additives, UV protection additives, antioxidants, and combinations thereof.

16. 10. The lead acid battery separator of claim 1, wherein the porous membrane comprises one of the group consisting of solid ribs, discrete interrupted ribs, continuous ribs, discontinuous ribs, discontinuous peaks, discontinuous protrusions, angled ribs, straight ribs, longitudinal ribs extending substantially in the lengthwise direction of the porous membrane, transverse ribs extending substantially in the widthwise direction of the porous membrane, transverse ribs extending substantially in the widthwise direction of the separator, discrete teeth, toothed ribs, serrated edges, serrated ribs, battlemented or battlemented ribs, curved ribs, folded ribs arranged in a continuous zigzag sawtooth configuration, broken interrupted zigzag sawtooth configuration, grooves, channels, textured areas, embossments, dimples, pillars, mini pillars, porous, non-porous, mini-ribs, cross mini-ribs, and combinations thereof.

17. A lead-acid battery comprising an electrolyte, a positive electrode, a negative electrode, and the separator according to claim 1 disposed therebetween.

18. A vehicle comprising the lead-acid battery of claim 17.

19. 10. The lead acid battery separator of claim 1, wherein the fibrous mat is one of the group consisting of an AGM separator, a paste paper, a scrim, a membrane, and combinations thereof.

20. 20. The lead acid battery separator of claim 19, wherein said conductive element or said nucleating additive is at least one of carbon and barium sulfate.

21. 21. The lead acid battery separator of claim 20, wherein the carbon is selected from the group consisting of conductive carbon, graphite, artificial graphite, activated carbon, carbon paper, acetylene black, carbon black, high surface area carbon black, graphene, high surface area graphene, Ketjenblack, carbon fiber, carbon filament, carbon nanotubes, open cell carbon foam, carbon mat, carbon felt, carbon buckminsterfullerenes ("buckyballs"), aqueous carbon suspensions, graphite flakes, oxidized carbon, and combinations thereof.

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