CN115395177A

CN115395177A - Battery separators, flooded lead acid batteries, and related methods

Info

Publication number: CN115395177A
Application number: CN202211167343.8A
Authority: CN
Inventors: 埃里克·H·米勒; M·尼尔·戈洛温; 阿希拉·克里斯哈拉莫斯; 马修·霍华德; 詹姆斯·P·佩里
Original assignee: Daramic LLC
Current assignee: Daramic LLC
Priority date: 2015-10-07
Filing date: 2016-01-11
Publication date: 2022-11-25
Also published as: JP2021177496A; JP2023116737A; KR20180066171A; JP2018530127A; WO2017062053A1; KR20240042191A; CN108292783A; EP3360194A1; EP3360194A4

Abstract

A battery separator is used for a flooded lead acid battery, in particular an enhanced flooded lead acid battery. The separator of the present invention provides enhanced electrolyte mixing and significantly reduced acid stratification by several technical means or combinations of technical measures in specific structures, materials, processes, etc. The prior art does not disclose the combination of technical measures according to the invention. The improved flooded lead acid battery may be advantageously employed in applications where the battery is maintained in a partially charged state, such as in start/stop vehicle systems. In addition, improved lead acid batteries, such as flooded lead acid batteries, improved systems including lead acid batteries and battery separators, improved vehicles including such systems, and/or methods of manufacture and/or use may be provided.

Description

Battery separators, flooded lead acid batteries, and related methods

The application is a divisional application, and the original priority date is 2015, 10 and 7; the original international application date is 2016, 1 and 11; the original international application number is PCT/US2016/012805; the date of entry into the chinese country phase is 2018, 5, month 31, chinese application number 201680070307.6; the original invention title is a flooded lead acid battery having improved performance, improved battery separator, and related methods.

Cross Reference to Related Applications

This application claims priority and benefit from U.S. provisional patent application serial No.62/238,373, filed on 7/10/2015. The entire contents of the above application are incorporated herein by reference.

Technical Field

In accordance with at least selected embodiments, the present disclosure or invention is directed to improved lead acid batteries, such as flooded lead acid batteries, improved systems including lead acid batteries and battery separators, improved vehicles including such systems, and/or methods of manufacture and/or use. In accordance with at least certain embodiments, the present disclosure or invention relates to improved flooded lead acid batteries and/or improved battery separators for such batteries, and/or methods of making, testing, and/or using such improved flooded lead acid batteries. Further, disclosed herein are methods, systems, batteries, and battery separators for reducing acid stratification, improving battery life and performance in flooded lead acid batteries.

Background

In order to reduce fuel consumption and tailpipe emissions, automobile manufacturers have implemented varying degrees of hybrid electric operation. One form of Hybrid Electric Vehicle (HEV) is sometimes referred to as a "micro HEV" or "micro hybrid. In such a micro-HEV or similar vehicle, the automobile may have an idle start/stop (ISS) function, wherein the engine may be shut off at various points during idle start/stop and/or regenerative braking. While this increases the fuel economy of the vehicle, it also increases the burden on the battery, which must power auxiliary devices (e.g., air conditioners, media players, etc.) when the vehicle is not in motion.

Conventional vehicles (e.g., automobiles without start/stop capabilities) may use conventional flooded lead acid batteries, such as SLI lead acid batteries. Since the engine is not shut down at all times, power is drawn from the battery only when the engine is started. As such, the battery is typically in an overcharged state, rather than a partially charged state. For example, such a conventional flooded lead acid battery, because it is typically in an overcharged state, may exist at greater than 95% charged, greater than 96%, greater than 97%, greater than 98%, greater than 99%, or even greater than 100% charged state. Upon overcharge, bubbles (e.g., hydrogen bubbles) are generated within a conventional lead-acid battery, and these circulating bubbles are used for the liquid electrolyte (acid) within the hybrid battery.

On the other hand, vehicles with start/stop constantly draw power from the battery, so the battery is always in a partially charged state. Upon partial charging, no bubbles are generated and internal mixing of the electrolyte is greatly reduced, resulting in acid stratification within the battery. Thus, acid stratification is a problem in start/stop flooded lead acid batteries and various enhanced flooded batteries, while acid stratification is not a problem for more conventional or traditional flooded lead acid batteries, which operate at overcharge or full charge (or nearly full).

Acid stratification is a term for the process of concentrated sulfuric acid concentration at the bottom of the cell, resulting in a correspondingly higher water concentration at the top of the cell. Acid stratification is undesirable in flooded lead acid batteries, such as enhanced flooded lead acid batteries or start/stop flooded lead acid batteries. The reduced acid content at the top of the electrode may inhibit uniformity and charge acceptance within the battery system and may increase the variation of internal resistance from top to bottom along the height of the battery. An increase in the acid level at the bottom of the battery can artificially increase the battery voltage, which can interfere with the battery management system and may send an unexpected/incorrect state of health signal to the battery management system. Overall, acid stratification results in higher resistance of the battery components, which may lead to electrode problems and/or reduced battery life. In view of the expectation that start/stop batteries and/or other enhanced flooded lead acid batteries will be increasingly used in hybrid and all-electric vehicles to increase vehicle fuel efficiency and reduce carbon dioxide emissions, solutions to reduce acid stratification and/or to improve acid mixing are highly desirable.

In some cases, acid stratification can be avoided using VRLA (valve regulated lead acid) technology, where the acid is held by gel electrolyte and/or Absorbent Glass Mat (AGM) battery separator systems. In contrast to free-fluid electrolytes in flooded lead acid batteries, in VRLA batteries, the electrolyte is absorbed on fibers or fibrous materials, such as glass fiber mats, polymer fiber mats, gel electrolytes, and the like. However, VRLA battery systems are much more expensive to manufacture than flooded battery systems. VRLA-AGM technology may be more sensitive to overcharge in some cases, may dry out at high temperatures, may gradually decrease in capacity, and may have a lower specific energy. Similarly, in some cases, gel VRLA technology may have higher internal resistance and may have reduced charge acceptance.

Accordingly, there is a need for further development of enhanced flooded lead acid batteries, such as enhanced flooded start/stop batteries that do not experience acid stratification during use. There is a need for improved enhanced flooded lead acid batteries having improved uniformity and performance over previously available batteries, and having performance comparable to that which may exist in certain VRLA-AGM batteries.

Disclosure of Invention

The present disclosure or invention, according to at least selected embodiments, may address the above and other needs. For example, in accordance with at least certain embodiments, the present disclosure or invention relates to new, improved, or optimized flooded lead acid batteries, systems, and separators for enhanced flooded lead acid batteries, and methods of making, testing, and/or using the same.

Disclosed herein are new, improved or optimized enhanced flooded lead acid batteries with a particular kind of separator. It has been surprisingly found that by appropriate selection of separator surface characteristics, acid stratification can be reduced and/or prevented, and a corresponding increase in battery performance can be observed, performance approaching, equal to, or even higher than that of certain VRLA-AGM batteries. Furthermore, it has been surprisingly found that such movement of the cells and separators of the present invention facilitates improved acid mixing or circulation, and/or reduces or entirely prevents acid stratification, without requiring some mechanical means or some tools (e.g., a pump for acid mixing) to effect acid mixing when using the separators described herein and the cells described herein and using them in motion. Various embodiments are described in further detail below.

In accordance with at least selected embodiments, aspects, or objects, the present disclosure or invention is directed to improved lead acid batteries, such as flooded lead acid batteries, improved systems including lead acid batteries and battery separators, improved vehicles including such systems, and/or methods of manufacture and/or use.

In accordance with at least selected embodiments, aspects, or objects, the present disclosure or invention may provide enhanced flooded lead acid batteries, such as enhanced flooded start/stop batteries, that do not experience acid stratification when in use, improved enhanced flooded lead acid batteries with improved uniformity and performance compared to previously existing, and/or improved enhanced flooded lead acid batteries that at least can compete with or exceed the performance capabilities of certain VRLA-AGM batteries.

Drawings

Fig. 1 includes a series of photographs comparing a battery cell having a serrated ribbed separator (these serrations are also referred to as stacking ribs or stacks) according to the invention (top row) with a battery cell having a conventional solid ribbed separator (bottom row) in which such solid ribs are vertically disposed along the separator. The spacing between the stacking ribs (rib tip to rib tip) of the separator shown in the top row is about 11 mm. Fig. 1 shows a side of a battery separator that generally faces a positive electrode in a flooded lead acid battery (e.g., a flooded lead acid battery in a partially charged state). However, such ribs may be included on both sides of the separator (e.g., may also be included on the side of the separator designed to face the negative electrode in a flooded lead acid battery). The battery shown in fig. 1 is subjected to 90 start/stop events or cycles. As shown in fig. 1, after 30, 60, and 90 start/stop cycles or events, the cells with serrated ribbed separators showed significantly less acid stratification than the cells with conventional separators.

Fig. 2 includes a series of photographs comparing a cell of the same type as fig. 1 with a serrated ribbed separator according to the invention (top row) with a cell with a conventional solid ribbed separator (bottom row). These batteries undergo 60 start/stop events or cycles and then rest overnight while an automobile travels 25 miles per hour. As shown in fig. 2, the battery cells with serrated ribbed separators showed significantly less acid stratification than the battery cells with conventional separators. This test validates the laboratory results shown in the photograph of fig. 1.

Fig. 3 includes a series of photographs comparing a battery cell with a narrower spaced serrated ribbed separator according to the invention (top row) with a battery cell with a conventional solid ribbed separator (bottom row) where the solid ribs are perpendicular along the separator. The spacing between the stacking ribs of the separator plates shown in the top row is approximately 7 mm. The battery is subjected to 90 start/stop events or cycles. As shown in fig. 3, after 30, 60, and 90 start/stop cycles or events, the cells with serrated ribbed separators showed significantly less acid stratification than the cells with conventional separators.

Fig. 4 includes a series of photographs comparing a battery cell having a dimpled separator according to the present invention (top row) with a battery cell having a conventional separator comprising solid large ribs and solid small ribs (bottom row) wherein such large and small solid ribs are perpendicular along the separator. The battery was subjected to 90 start/stop events or cycles. As shown in fig. 4, after 30, 60, and 90 start/stop cycles or events, the cells with dimpled separators showed significantly less acid stratification than the cells with conventional separators. Thus, the solid ribs (e.g., shown in the bottom row of photographs in fig. 4) actually inhibit acid mixing of the separator within the start/stop lead acid battery.

Fig. 5 includes a series of photographs comparing a battery cell having a dimpled separator according to the present invention (top row) with a battery cell having a separator with solid ribs extending vertically along the separator in combination with dimples (bottom row). The battery is subjected to 90 start/stop events or cycles. As shown in fig. 5, the battery cells with dimpled separators (top row) showed less acid stratification than the start/stop lead acid battery cells in the bottom row with separators comprising solid ribs combined with dimples. However, some acid mixing is shown in the bottom row (e.g., as compared to the bottom row in fig. 1-4). For example, in some pictures in the bottom row, distinct areas or pockets of low density acid can be seen; however, acid mixing can also be seen. The bottom row of photographs demonstrates that the combination of serrations and solid ribs or the combination of dimples and solid ribs can prove effective in various batteries, systems, and methods in accordance with the present invention.

Fig. 6 includes a set of photographs comparing a battery cell having a dimpled separator plate (top row) according to the present invention with a battery cell having a separator plate with solid ribs extending diagonally (at a small angle relative to the vertical direction of the separator plate) along the separator plate. The battery is subjected to 90 start/stop events or cycles. As shown in fig. 6, the cells with dimpled separators (top row) showed less acid stratification than the starting/ending lead acid cells in those photographs shown in the bottom row of fig. 1-4. With respect to the bottom row of photographs of FIG. 6, in 60 cycles or 60 start/stop events, it can be seen that there is still some acid stratification; however, acid stratification improved after 90 cycles.

Fig. 7A and 7B include photographs comparing a conventional solid ribbed separator (7A) with no separator (7B) at all in a can filled with an acid of 1.28 specific gravity (which is mixed). FIG. 7A includes a photograph of a conventional ribbed separator; acid stratification is indicated by the red acid concentration at the bottom of the tank and the clear liquid at the top of the tank. Fig. 7B includes a photograph with a lead gate only therein without any spacers; as shown by the red color throughout the tank, much less acid stratification occurred. Fig. 7A and 7B help illustrate that a solid ribbed conventional separator may prevent acid mixing and may promote acid stratification within a start/stop flooded lead acid battery. Likewise, FIG. 7B provides a reference without a separator plate to which individual separator plates can be compared and contrasted.

Fig. 8 includes photographs of a battery cell constructed using a serrated ribbed separator according to the invention prior to testing for acid delamination.

Fig. 9 includes photographs of the battery cell of fig. 8 assembled in a housing for acid stratification testing. Lead strips are placed over the electrode sets and separators. Once the acid is added to the housing, the acid face may be a few millimeters above the wire strips (in some cases, by way of example only, about 3mm above the wire strips). Since the housing containing the electrodes and separator is used to test acid stratification within the battery cell, in certain embodiments, it may be preferred that the direction of motion of the test simulate the motion of a start/stop electric vehicle and be in the y-direction of the photograph of fig. 9, such that when the vehicle starts, accelerates, decelerates, and/or stops, the acid moves over the surface of the electrodes. The graph can also be seen as the top of the photograph of fig. 9 facing the front bumper of an electric vehicle with start/stop capability and the bottom of the photograph of fig. 9 facing the rear bumper of the same electric vehicle, while a bystander is looking down at a set of electrodes + separator + lead strips and soon is about to be filled with acid for the acid stratification test.

Fig. 10 includes a photograph of a cross-sectional view of serrations or serrated ribs on a separator plate used in accordance with various embodiments described herein.

Fig. 11 includes two views of a profile of a serrated separator plate used in accordance with various embodiments described herein.

Fig. 12 depicts a graph of the conductivity of a sulfuric acid solution at 25 ℃. This figure is useful for understanding that acid stratification may lead to non-uniform current flow due to differences in conductivity in the high acid region and the low acid region of the cell and/or battery.

Fig. 13 includes a photograph of a battery cell constructed similarly to the battery cell depicted in fig. 6. However, for the battery cell depicted in fig. 13, the separator is inserted into the system perpendicular to the direction of vehicle motion (whereas for the battery cell shown in the figure in fig. 6, the separator is inserted into the system parallel to the direction of motion, similar to the directional description of fig. 9 above). In various embodiments, it may be preferred that the separator be positioned parallel to the direction of motion of the vehicle and battery system. This is because the photograph shown in fig. 13 shows that after 60 start/stop cycles or events, acid stratification is still occurring, with no good acid mixing. Taking the top row of fig. 13 as an example, even though a dimpled separator is used therein according to various embodiments of the present invention, acid stratification still occurs and acid mixing is not optimal, all due to the placement of the battery and separator within the system.

Fig. 14 includes photographs of a battery separator containing serrated ribs for encapsulating electrodes to make a start/stop automotive flooded lead acid battery for testing according to various embodiments described herein, the results of which are described below.

Fig. 15A-15D include diagrams of a plurality of serrated profiles of a separator plate according to various embodiments herein. Various optimized profiles for separators for improved and enhanced acid mixing are disclosed herein, and the diagrams set forth in fig. 15A-15D are merely examples of such optimized profiles; many other optimized profiles fall within the scope of the improved separators, cells, systems, and methods described and claimed herein.

Fig. 16 includes a graph depicting a cycle test of one example of an enhanced flooded battery (or a flooded battery operating in an enhanced mode). In the current newer battery applications, the enhanced flooded battery operates at a lower state of charge than previously known flooded lead acid batteries (which typically move over overcharge conditions or over 100% state of charge). Thus, such enhanced flooded batteries may operate at less than 95% state of charge (SoC), in some cases, less than 90%, in some cases, less than 85%, in some cases, less than 80%, in some cases, less than 70%, in some cases, less than 60%, in some cases, less than 50%, in some cases, less than 25%, in some cases, even less than 10%. In this particular figure, a battery having a 17.5% depth of discharge (DoD) was cycle tested and the separator used was a conventional ribbed separator such as that shown in the bottom row of photographs in fig. 1. The battery exhibits the ability to deliver energy under high cycling conditions in a partially discharged state and is capable of operating well in a lead sulfate rich environment. Batteries tested as in fig. 16 and used for start/stop applications have significantly improved energy flux compared to standard SLI batteries (e.g., batteries listed in standards such as EN 50342). Because such enhanced flooded batteries and/or flooded batteries for start/stop applications operate in a partially charged state, they need to have higher charging efficiency and/or need to be more receptive to charging. In some cases, enhanced flooded batteries use various additives in combination with one or more electrodes to increase the efficiency of charging and/or to form a battery that is more receptive to charging. However, the reinforced baffle described herein may achieve the same objectives.

Detailed Description

In various embodiments described herein, separators are employed for enhanced electrolyte mixing and/or circulation in flooded lead acid batteries. In certain embodiments, a separator is employed that reduces acid stratification. In various embodiments, a battery is disclosed in which acid stratification is substantially reduced as compared to known batteries due to an improved or enhanced separator system for acid mixing and prevention of acid stratification. For example, such a battery may be used in a vehicle that is a battery in motion. In various embodiments, the motion of the vehicle (e.g., an electric vehicle containing a start/stop lead acid battery) actually mixes the acid or electrolyte, in conjunction with the enhanced battery separator described herein, unexpectedly results in a significant reduction in acid stratification and a significant improvement in acid mixing shown herein, within the start/stop flooded lead acid battery and/or enhanced flooded lead acid battery or battery operating in enhanced mode. For example, starting/stopping and starting of an electric vehicle provides energy in various embodiments herein to mix acid/electrolyte within an enhanced flooded lead acid battery and improve acid mixing and reduce or completely prevent acid stratification.

In accordance with at least certain embodiments, the polyolefin separator may be a polyolefin sheet having serrated ribs, protrusions, mounds, dimples, embossments, and combinations thereof on one or more surfaces. In other embodiments, the polyolefin separator may be a polyolefin sheet having serrated ribs, protrusions, mounds, dimples, embossments on one or more surfaces, in combination with certain additives.

The separator is preferably made of a polyolefin, such as polypropylene, ethylene-butene copolymer, preferably polyethylene, more preferably high molecular weight polyethylene, i.e. polyethylene having a molecular weight of at least 600,000 or high density polyethylene, such as polyethylene having a molecular weight of at least 500,000. In some embodiments, one or more ultra-high molecular weight polyethylenes are used, i.e., polyethylenes having a molecular weight of at least 1,000,000, particularly over 4,000,000, in some cases 5,000,000 to 8,000,000 (as measured by viscosity measurements and calculated by the Margolie equation), a standard load melt index of substantially 0 (determined using a standard load of 2,160g according to ASTM D1238 (condition E)) and a viscosity value of no less than 600ml/g, preferably no less than 1000ml/g, more preferably no less than 2,000ml/g, most preferably no less than 3,000ml/g (determined at 130 ℃ in a solution of 0.02g of polyolefin in 100g of decalin).

According to at least one embodiment, the separator is made of Ultra High Molecular Weight Polyethylene (UHMWPE) mixed with processing oil and silica (e.g. precipitated silica and/or fumed silica). According to at least one other embodiment, the separator is composed of Ultra High Molecular Weight Polyethylene (UHMWPE) mixed with processing oil, additives and silica (e.g., precipitated silica). The separator preferably comprises a homogeneous mixture of 8 to 100% by volume of polyolefin, 0 to 40% by volume of plasticizer and 0 to 92% by volume of inert filler material. In some cases, the preferred filler is dry, finely divided silica. However, the filler may be selected from silica, mica, montmorillonite, kaolinite, asbestos, talc, diatomaceous earth, vermiculite, natural and synthetic zeolites, cement, calcium silicate, clay, aluminum silicate, sodium aluminum silicate, aluminopolysilicate, alumina silica gel, glass particles, carbon black, activated carbon, carbon fiber, charcoal, graphite, titanium oxide, iron oxide, copper oxide, zinc oxide, lead oxide, tungsten, antimony oxide, zirconium oxide, magnesium oxide, aluminum oxide, molybdenum disulfide, zinc sulfide, barium sulfate, strontium sulfate, calcium carbonate, magnesium carbonate, and the like, and various combinations thereof.

Preferred plasticizers are petroleum oils and/or waxes. Since the plasticizer is the most easily removed component from the polymer-filler-plasticizer composition, it can be used to impart porosity to the battery separator.

The separator has an average pore diameter of less than 1 μm. Preferably, more than 50% of the pores have a diameter of 0.5 μm or less. It may be preferred that at least 90% of the pores have a diameter of less than 0.9 μm. The average pore diameter of the microporous separator is preferably in the range of 0.05 to 0.9 μm, and in some cases 0.1 to 0.3 μm.

In some cases, pore size can be measured using mercury intrusion methods described by Ritter, h.l. and Drake, l.c. in ind. According to this method, mercury is pressed into holes of different sizes by means of a porosimeter (porosimeter model 2000, carlo Erba) by varying the pressure exerted on the mercury. Pore distribution can be determined by evaluating the raw data with the millestone 200 software.

The thickness of the separator is preferably greater than 0.1mm and less than or equal to 5.0mm. The thickness of the spacer may be in the range of 0.15-2.5mm, 0.25-2.25mm, 0.5-2.0mm, 0.5-1.5mm or 0.75-1.5mm (this thickness takes into account the thickness of the entire spacer, including any serrated ribs, protrusions, indentations, etc.). In some cases, the spacer may be about 0.8mm or 1.1mm thick. The separator may or may not have a laminate material adhered to one or more surfaces thereof.

In various embodiments, the microporous polyolefin separator layer comprises ribs, such as serrated ribs. Preferred ribs may be 0.008mm to 1mm high and may be spaced 0.001mm to 20mm apart, while a preferred backweb thickness of the microporous polyolefin separator layer without the serrated ribs or protrusions may be about 0.05mm to about 0.500mm (e.g., about 0.25mm in certain embodiments). For example, the ribs may be spaced 0.05mm, 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1.0mm, 1.2mm, 1.4mm, 1.6mm, 1.8mm, 2.0mm, 2.25mm, 2.5mm, 2.75mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm or 10mm. In some embodiments, the ribs may be in the form of, for example, 0 to 90 degrees relative to each other on one side of the separator layer or on both sides of the polyolefin separator. Various forms including ribs on both sides of the separator layer may include negative cross-ribs (negative cross-ribs) on the second or back side of the separator. In some cases, the height of such negative transverse ribs may be 0.025mm to about 0.1mm.

In certain preferred embodiments, the ribs may be serrated. The average tip length of the serrations may be 0.05mm to 1mm. For example, the average tip length can be greater than or equal to 0.05mm, 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, or 0.9mm; and/or less than or equal to 1.0mm, 0.9mm, 0.8mm, 0.7mm, 0.6mm, 0.5mm, 0.4mm, 0.3mm, 0.2mm, or 0.1mm.

The average base length of the serrations may be from 0.05mm to 1mm. For example, the average base length can be greater than or equal to 0.05mm, 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, or 0.9mm; and/or less than or equal to 1.0mm, 0.9mm, 0.8mm, 0.7mm, 0.6mm, 0.5mm, 0.4mm, 0.3mm, 0.2mm, or 0.1mm.

The average height of the serrations may be from 0.05mm to 4mm. For example, the average height can be greater than or equal to 0.05mm, 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, or 0.9mm; and/or less than or equal to 1.0mm, 0.9mm, 0.8mm, 0.7mm, 0.6mm, 0.5mm, 0.4mm, 0.3mm, 0.2mm, or 0.1mm. For embodiments where the serration height is the same as the rib height, the serrated ribs may also be referred to as protrusions. Such ranges may be applicable to separators for industrial pull start/stop batteries, where the total thickness of the separator may typically be from about 1 to about 4mm, and automotive start/stop batteries, where the total thickness of the separator may be somewhat less (e.g., typically from about 0.3mm to about 1 mm).

The average center-to-center spacing of the serrations may be from 0.1mm to 50 mm. For example, the average center-to-center distance may be greater than or equal to 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1.0mm, 1.25mm, or 1.5 mm; and/or less than or equal to 1.5mm, 1.25mm, 1.0mm, 0.9mm, 0.8mm, 0.7mm, 0.6mm, 0.5mm, 0.4mm, 0.3mm, or 0.2mm.

The serrations may have an average height to base width ratio of 0.1. For example, the average height to base width ratio can be greater than or equal to 0.1, 25; and/or less than or equal to 500.

The serrations may have an average base-to-top aspect ratio from 1000. 1, 5.

In some embodiments, the separator may be dimpled. The depressions are typically protrusion-type features on one or more surfaces of the separator. The thickness of the pits may be 1-99% of the thickness of the spacer. For example, the average thickness of the dimples can be less than 95%, 90%, 85%, 80%, 75%, 70%, 65%, 60%, 55%, 50%, 45%, 40%, 35%, 30%, 25%, 20%, 15%, 10%, or 5% of the separator thickness. The dimples may be arranged in rows along the separator plate. The rows or columns may be spaced 0.001mm to 10mm apart. For example, the rows may be spaced 0.05mm, 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1.0mm, 1.2mm, 1.4mm, 1.6mm, 1.8mm, 2.0mm, 2.25mm, 2.5mm, 2.75mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm or 10mm apart. Rather, the pits may be arranged in a random array or in a random manner.

The pits may have an average pit length of 0.05mm to 1mm. For example, the average pit length can be greater than or equal to 0.05mm, 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, or 0.9mm; and/or less than or equal to 1.0mm, 0.9mm, 0.8mm, 0.7mm, 0.6mm, 0.5mm, 0.4mm, 0.3mm, 0.2mm, or 0.1mm.

The pits may have an average pit width of 0.01mm to 1mm. For example, the average dimple width can be greater than or equal to 0.05mm, 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, or 0.9mm; and/or less than or equal to 1.0mm, 0.9mm, 0.8mm, 0.7mm, 0.6mm, 0.5mm, 0.4mm, 0.3mm, 0.2mm, or 0.1mm.

The dimples may have an average center-to-center distance of 0.1mm to 50 mm. For example, the average center-to-center distance may be greater than or equal to 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1.0mm, 1.25mm, or 1.5 mm; and/or less than or equal to 1.5mm, 1.25mm, 1.0mm, 0.9mm, 0.8mm, 0.7mm, 0.6mm, 0.5mm, 0.4mm, 0.3mm, or 0.2mm.

The shape of the pits may be quadrilateral, such as square and rectangular. The pits may have an average pit length to pit width ratio of 0.1 to 100. 1, 5.

In some embodiments, the dimples may be substantially circular. The circular pits may have a diameter of about 0.05 to 1.0 mm. For example, the average dimple diameter can be greater than or equal to 0.05mm, 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, or 0.9mm; and/or less than or equal to 1.0mm, 0.9mm, 0.8mm, 0.7mm, 0.6mm, 0.5mm, 0.4mm, 0.3mm, 0.2mm, or 0.1mm.

Various other shapes of dimples may also be included. By way of example only, such a dimple may be a triangle, pentagon, hexagon, heptagon, octagon, etc.

In some embodiments, the baffles may feature a combination of serrations and/or dimples. For example, the separator may have a series of serrated ribs extending along the separator from top to bottom and a second series of serrated ribs extending horizontally along the separator. In other embodiments, the separator may have an alternating sequence of zigzag ribs, dimples, and/or continuous and/or interrupted solid ribs.

Table 1 below includes several embodiments of separators having serrations and/or dimples and various parameters that may be used to form such separators to prevent acid stratification and enhance acid mixing of flooded lead acid batteries (sometimes referred to as enhanced flooded batteries).

TABLE 1

The separators disclosed herein preferably provide enhanced electrolyte mixing and/or acid circulation as compared to conventional separators. In certain embodiments, the separator provides less acid stratification as measured by the electrolyte density at the top and bottom of the cell. The density difference may be less than 50%, 45%, 40%, 35%, 30%, 25%, 20%, 15%, 10%, 5%, 2.5%, or 1% after the cell has undergone 30, 60, or 90 start/stop events or cycles. In certain selected embodiments, the density difference may be less than 50%, 45%, 40%, 35%, 30%, 25%, 20%, 15%, 10%, 5%, 2.5%, or 1% after the cell has been held stationary for 24, 48, or 72 hours.

The separators used in various embodiments herein may incorporate one or more additives. This is because the additive may enhance the separator of the stop/start flooded lead acid battery of certain vehicles. One such additive that may be present in the polyolefin is a surfactant, while another such additive may include one or more latex additives. Suitable surfactants include surfactants such as alkyl sulfates; an alkyl aryl sulfonate; alkylphenol-alkylene oxide addition products; a soap; alkyl-naphthalene sulfonates; dialkyl esters of sulfosuccinates; a quaternary amine; block copolymers of ethylene oxide and propylene oxide; and salts of monoalkyl and dialkyl phosphates. The additive may be a nonionic surfactant, such as polyol fatty acid esters, polyethoxylated fatty alcohols, alkyl polysaccharides such as alkyl polyglycosides and mixtures thereof, amine ethoxylates, sorbitan fatty acid ester ethoxylates, organosilicone-based surfactants, ethylene vinyl acetate terpolymers, ethoxylated alkyl aryl phosphate esters, and sucrose esters of fatty acids.

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

R(OR ¹ ) _n (COOM ^x+ _1/x ) _m (I)

Wherein, the first and the second end of the pipe are connected with each other,

r is a non-aromatic hydrocarbon radical having from 10 to 4200 carbon atoms, preferably from 13 to 4200 carbon atoms, which may be interrupted by oxygen atoms,

·R ¹ is H, - (CH) ₂ ) _k COOM ^x+ _1/x Or- (CH) ₂ ) _k —SO ₃ M ^X+ _1/X Preferably H, wherein k is 1 or 2,

m is an alkali or alkaline earth metal ion, H ⁺ Or NH ₄ ⁺ In which not all variables M have H at the same time ⁺ The base group of the compound is a basic group,

n is 0 or 1 and n is,

m is 0 or an integer from 10 to 1400, and

x is 1 or 2 and x is,

the ratio of oxygen atoms to carbon atoms in the compound of formula (I) is in the range 1.5 to 1. However, it is preferred that only one of the variables n and m is unequal to 0.

Non-aromatic hydrocarbyl refers to a group that is free of aromatic groups or that itself represents one. The hydrocarbon group may be interrupted by oxygen atoms, i.e. contain one or more ether groups.

R is preferably a straight or branched chain aliphatic hydrocarbon group which may be interrupted by oxygen atoms. Saturated, uncrosslinked hydrocarbon radicals are very particularly preferred.

The additives used to produce the various porous membranes described herein for the compounds of formula (I) may also provide effective protection against oxidative damage to such separators. In some embodiments, porous membranes are preferred which comprise an additive comprising a compound according to formula (I), wherein R is a hydrocarbon radical having from 10 to 180, preferably from 12 to 75 and very particularly preferably from 14 to 40 carbon atoms, which may be interrupted by from 1 to 60, preferably from 1 to 20 and very particularly preferably from 1 to 8 oxygen atoms, particularly preferably of the formula R ² —[(OC ₂ H ₄ ) _p (OC ₃ H ₆ ) _q ]-a hydrocarbon radical of (a), wherein,

o R ² is an alkyl radical having from 10 to 30 carbon atoms, preferably from 12 to 25, particularly preferably from 14 to 20 carbon atoms,

op is an integer from 0 to 30, preferably from 0 to 10, particularly preferably from 0 to 4, and

oq is an integer from 0 to 30, preferably from 0 to 10, particularly preferably from 0 to 4,

o particularly preferred compounds are those in which the sum of p and q is from 0 to 10, in particular from 0 to 4,

n is 1, and

m is 0.

Formula R ² —[(OC ₂ H ₄ ) _p (OC ₃ H ₆ ) _q ]It is to be understood that the sequences of the radicals in brackets are also included which differ from those shown. For example according to the invention, wherein the groups in brackets are exchanged by (OC) ₂ H ₄ ) And (OC) ₃ H ₆ ) Radical forming compounds are suitable.

R ² Additives which are linear or branched alkyl groups having from 10 to 20, preferably from 14 to 18, carbon atoms have proven particularly advantageous. OC ₂ H ₄ Preferably represents OCH ₂ CH ₂ ，OC ₃ H ₆ Represents OCH (CH) ₃ )CH ₂ And/or OCH ₂ CH(CH ₃ )。

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

Additives of the type m =0 which are insoluble or poorly soluble in water and sulfuric acid have proven particularly advantageous.

Additives containing compounds of the formula (I) are also preferred, in which case

R is an alkane radical having from 20 to 4200, preferably from 50 to 750 and very particularly preferably from 80 to 225 carbon atoms,

m is an alkali or alkaline earth metal ion, H ⁺ Or NH ⁴⁺ Especially alkali metal ions such as Li ⁺ 、Na ⁺ And K ⁺ Or H ⁺ In which not all variables M have H at the same time ⁺ The base group of the compound is a basic group,

n is a number of 0, and,

m is an integer from 10 to 1400, and

x is 1 or 2.

Polyacrylic acids, polymethacrylic acids and acrylic acid-methacrylic acid copolymers in which the acid groups are at least partially (preferably 40%, particularly preferably 80%) neutralized are particularly mentioned here as suitable additives. The percentages refer to the number of acid groups. Very particular preference is given to poly (meth) acrylic acid which is present entirely in salt form. Poly (meth) acrylic acid refers to polyacrylic acid, polymethacrylic acid and acrylic acid-methacrylic acid copolymers. Poly (meth) acrylic acids are preferred, in particular polyacrylic acids having an average molar mass Mw of 1,000 to 100,000g/mol, particularly preferably 1,000 to 15,000g/mol and very particularly preferably 1,000 to 4,000g/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 constant).

Copolymers of (meth) acrylic acid are also suitable, particularly suitable copolymers comprising, in addition to (meth) acrylic acid, ethylene, maleic acid, methyl acrylate, ethyl acrylate, butyl acrylate and/or ethylhexyl acrylate as comonomers. Copolymers containing at least 40% by weight, preferably at least 80% by weight, of (meth) acrylic monomers are preferred, the percentages being based on the acid form of the monomer or polymer.

For the neutralization of polyacrylic acid polymers and copolymers, alkali metal and alkaline earth metal hydroxides such as potassium hydroxide, in particular sodium hydroxide, are particularly suitable.

The porous membrane may be provided in various ways with one or more additives. For example, the additives may be applied to the polyolefin at the completion (i.e., after extraction) or added to the coating mixture used to produce the porous film. According to one possible preferred embodiment, the additive or the solution of the additive may be applied to the surface of the porous membrane or to the surface of the coating. This variant is particularly suitable for the application of non-heat-stable additives and additives soluble in the solvent used for the subsequent extraction. Particularly suitable solvents as additives according to the invention are low molecular weight alcohols, such as methanol and ethanol, and also mixtures of these alcohols with water. The application may occur on the side of the porous membrane facing the negative electrode, the side facing the positive electrode, or both sides. For embodiments in which the coating is present on only one side of the porous membrane, the additive may be applied to the coating, to the uncoated side of the coating or to both sides of the separator.

The additive may be present at a level of at least 0.5g/m ² 、1.0g/m ² 、1.5g/m ² 、2.0g/m ² 、2.5g/m ² 、3.0g/m ² 、3.5g/m ² 、4.0g/m ² 、4.5g/m ² 、5.0g/m ² 、5.5g/m ² 、6.0g/m ² 、6.5g/m ² 、7.0g/m ² 、7.5g/m ² 、8.0g/m ² 、8.5g/m ² 、9.0g/m ² 、9.5g/m ² Or 10.0g/m ² The density of (a) exists. The additive may be present in an amount of from 0.5 to 10g/m ² 、1.0-10.0g/m ² 、1.5-10.0g/m ² 、2.0-10.0g/m ² 、2.5-10.0g/m ² 、3.0-10.0g/m ² 、3.5-10.0g/m ² 、4.0-10.0g/m ² 、4.5-10.0g/m ² 、5.0-10.0g/m ² 、5.5-10.0g/m ² 、6.0-10.0g/m ² 、6.5-10.0g/m ² 、7.0-10.0g/m ² 、7.5-10.0g/m ² 、5.0-10.5g/m ² 、5.0-11.0g/m ² 、5.0-12.0g/m ² Or 5.0-15.0g/m ² The density range of (a) is present on the separator.

Application can also be carried out by dipping the polyolefin layer into the additive or additive solution and subsequently selectively removing the solvent, for example by drying. In this way, the application of the additive may be combined with extraction, which is for example common during the production of microporous polyolefin separator layers.

The separators, methods, batteries, and battery systems described herein can provide improved electrolyte circulation and less acid stratification mixing over time. This is particularly important for deep cycle and/or enhanced rich lead acid batteries, where acid stratification can significantly reduce battery performance. Various flooded lead acid batteries, enhanced flooded lead acid batteries, and applications thereof may benefit from the improved separators, methods, batteries, and systems described herein. Various start/stop vehicles, including, but not limited to, various electric vehicles, automobiles, hybrid vehicles, forklifts, golf carts, neighborhood electric vehicles, and the like, particularly vehicles and/or batteries that are not fully charged or that do not reach a 100% state of charge (or are overcharged) to exist in a partially charged state, may benefit from the improved separators, batteries, battery systems, and methods described herein.

The use of the enhanced pregnant separators (also referred to as acid mixing separators) described herein for enhanced pregnant batteries, particularly batteries in motion, surprisingly and unexpectedly provides enhanced pregnant batteries that significantly improve acid mixing and/or acid circulation, thereby significantly reducing or completely preventing acid stratification within the enhanced pregnant batteries. This is important because the flow and circulation of acid along the entire separator means that the entire cell is being used, rather than some smaller portion of the cell. That is, using the enhanced separator, battery, system and method of the present invention, electrolyte (e.g., sulfuric acid) flows freely to and along all or substantially all portions of the separator, and thus to and along all portions of the positive and negative active materials on the electrodes. Conversely, the entire portion of the separator, and thus the positive and negative active materials on either side of the separator, is completely free of acid and is therefore not fully utilized to power the device/vehicle in which the battery is used, due to acid stratification (see, by way of example only, photographs in the bottom row of fig. 1-4, where a red indicator has been added to the acid, making the acid clearly visible and present in the lower half of the test cells versus clear liquid, i.e., water, clearly visible and present in the upper half of those test cells). Thus, the improved separators, batteries, systems, and methods described herein greatly reduce acid stratification in flooded lead acid batteries (e.g., enhanced flooded batteries).

The reason for the fear of acid stratification is the non-uniformity of the current density generated on the surfaces of the positive and negative plates or electrodes. The curve shown in FIG. 12 indicates H ₂ SO ₄ Conductivity versus concentration.

In some preferred embodiments of the invention, the serrations present on one or more surfaces of the separator are unevenly distributed. Additionally, in some preferred embodiments, the dimples present on one or more surfaces of the separator are not uniformly distributed. For example, the serrations and pits themselves may not be uniformly sized (e.g., may be randomly sized), and the spacing between the serrations and/or pits may be random and/or non-uniform. For example, the various serrations and/or dimples used herein may be present on one or both surfaces of the separator in an ordered or disordered array. In addition, the various ribs used herein, such as the serrated ribs, may be non-linear. For example, some of the serrated ribs may be in a wavy form or a non-linear form.

In various embodiments, when the separator is positioned within an enhanced flooded battery, the enhancement of the separator parallel to the direction of motion of the battery travel, embodies the effects of an enhanced flooded separator for an enhanced flooded battery described herein. This effect can be seen by comparing the ideal results of fig. 6 with the non-ideal results of fig. 13. In the photograph of fig. 13, acid stratification was still observed even with separators having reinforced acid mix profiles. This is because the battery cell in fig. 13 is placed so that the reinforcement on the separator and the electrodes is perpendicular to the direction of movement of the battery traveling in the vehicle. Placing the battery in a vehicle, with the electrodes and separator parallel to the start and stop inertia, will allow better mixing of the acid than a perpendicular placement. When vertical, the electrodes and separators prevent acid turbulence and mixing, rather than promoting it.

The various reinforcing spacers described herein, such as spacers having serrations for improved acid mixing and acid circulation, may have different spacing and/or different forms. By way of example only, fig. 15A-15D illustrate examples of serrated ribs that may be effective in the present invention. Such forms and others (uniform and non-uniform, and ordered and disordered) may allow for improved CCA (cold start amperage) within flooded lead acid batteries, as well as other key improvements in battery electrical performance. In the zig-zag form as shown in fig. 15A-15D (by way of example only), the surface area is reduced by about 53% compared to a separator with solid ribs (control), allowing the ribs to contact less PAM (positive electrode active material) resulting in improved CCA performance. In versions similar to those shown in fig. 15A-15D, rib mass can be reduced by 33% compared to solid rib profiles (control), allowing for more acid availability and improved performance. In addition, maintaining PAM (positive active material) compression with a balance of rib mass and open pores is important for acid mixing and availability.

Furthermore, the arrangement and design of the protrusions (such as dimples, serrations, etc.) is preferably optimized for compression to not facilitate PAM shedding and is preferably supported on the gate frame so as not to push particles into intimate contact with the positive gate frame or current collector.

The battery of the present invention can save cost and requires less lead to achieve excellent performance due to the increased utilization of PAM. Thus, the cost of the battery can be reduced, which is required by the automobile manufacturer, and the weight of the battery can be reduced, which is also required by the automobile manufacturer.

In some cases, the reinforced baffle used in the present invention may have an optimized profile having a rib surface area that is 10-90% of the surface area of the conventional rib, preferably 30-70% of the surface area of the conventional rib, and more preferably, in some cases, 40-60% of the surface area of the conventional rib, as compared to the rib surface area of a conventional rib profile, such as a solid vertical rib profile. All of which depend on the rib geometry, the rib spacing, and the ultimate goal of improving acid mixing and preventing acid stratification, all of which have been optimized.

Examples

Fig. 8 and 9 show battery experiments performed in the battery cell container. The battery test cell shown in these photographs has a white casing and a set of lead electrodes with the following general attributes:

TABLE 2

In other examples shown below, a commercially available set 31 of plates/set Ca/Ca expanded the battery test data. In this table, the separator marked "new" has a saw-toothed profile as shown in the envelope of fig. 14, while the result marked "control" has solid ribs perpendicular along the separator. These results demonstrate unexpected and/or surprising findings regarding the battery performance improvement of start/stop enhanced flooded lead acid batteries using enhanced separators according to the present invention. It is noted that the results are still improved in the table below even when the battery in the vehicle is not moving significantly, but is only in general motion, moving from one place to another in the factory for testing. Thus, in conjunction with energy from the motion of the vehicle and/or from various start/stop events, battery performance results may be more significantly improved.

TABLE 3

Mean improvement of new vs. control	48	33.5	0.101
				% improvement	3.5％	3.6％	0.8％
Improvement in standard deviation	(1.17)	(5.99)	(0.00)
				Note	Higher discharge performance with improved quality	Improved cold start standard deviation

The importance of the Midtronic CCA test is that it is not a global standard test, but rather a handheld device that uses an algorithm to quickly and easily calculate battery performance. The increase in surface area of the positive grid exposed to the acid allows for improved conductance and improved electrode performance using an acid mixed separator. Although not an industry standard, its simplicity and ease of use are considered by purchasing decisions throughout the world today. Improving the performance of the algorithmic tester is critical to customer satisfaction, and the improvement of the acid mixing barrier contributes to this result, as shown in table 3 #.

The combinations and methods of the following claims are not to be limited in scope by the specific combinations and methods described herein, which are intended as illustrations of some aspects of the claims. Any combination and method that is functionally equivalent is intended to fall within the scope of the claims. Various modifications in addition to the combinations and methods shown and described herein are intended to fall within the scope of the appended claims. Moreover, although only certain representative compositions and method steps disclosed herein have been specifically described, other combinations of the compositions and method steps, even if not specifically recited, are intended to fall within the scope of the appended claims. Thus, steps, elements, components, or combinations of components may or may not be specifically mentioned herein, but other combinations comprising steps, elements, components, and combinations of components are intended to be included even if not specifically stated.

The term "comprising" and variants thereof, as used herein, are used synonymously with the term "comprising" and variants thereof, and are open, non-limiting terms. Although the terms "comprising" and "including" have been used herein to describe various embodiments, the terms "consisting essentially of and" consisting of may be used in place of "comprising" and "including" to provide more specific embodiments of the invention. Except where noted, all numbers expressing geometries, dimensions, and so forth used in the specification and claims are to be understood at the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, as interpreted in accordance with the number of significant digits and ordinary rounding techniques.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The publications cited herein and the materials cited therein are specifically incorporated by reference.

Claims

1. A flooded lead acid battery comprising a microporous polyolefin battery separator, wherein,

the separator comprises rows of serrated ribs, interrupted ribs, dimples or combinations thereof, wherein the row spacing is 0.1-20mm; the battery is in motion; and the motion provides energy for enhanced or improved acid mixing.

2. A flooded lead acid battery comprising a microporous polyolefin battery separator, wherein the separator comprises serrated ribs,

the serrations are used to improve acid mixing and acid circulation, having different pitches and/or different patterns; the surface area is reduced by about 53% compared to a separator with solid ribs without serrations (control), allowing the ribs to have less contact with the positive active material, resulting in improved CCA performance; alternatively, the rib mass is reduced by 33%, allowing for more acid availability and improved performance.

3. A flooded lead acid battery comprising a microporous polyolefin battery separator, wherein the separator comprises serrated ribs,

the average top length of the sawtooth ribs is 0.05-1mm, or the average bottom length is 0.05-1mm; or

The serrations have an average base-to-aspect ratio from 1000.

4. A flooded lead acid battery comprising a microporous polyolefin battery separator, wherein the separator comprises serrated ribs, interrupted ribs, dimples, or a combination thereof;

the ribs of the separator have a surface area of 10-90% of the surface area of conventional, continuous, solid, vertical ribs.

5. A flooded lead acid battery comprising a microporous polyolefin battery separator, wherein the separator comprises serrated ribs, interrupted ribs, dimples, or a combination thereof;

the partition plate comprises a plurality of rows of concave pits, and the row spacing of the concave pits is 0.001-10mm; the pits have an average pit length of 0.05mm to 1mm; and/or the dimples may have an average dimple width of 0.01mm to 1mm.

6. The flooded lead acid battery of one of claims 1 to 5,

the microporous polyolefin battery separator comprises polyethylene, preferably the separator is made of Ultra High Molecular Weight Polyethylene (UHMWPE) mixed with a processing oil and silica;

the battery separator further comprises a filler, preferably a dry finely divided silica; or the filler is selected from the group consisting of silica, mica, montmorillonite, kaolinite, asbestos, talc, diatomaceous earth, vermiculite, natural and synthetic zeolites, cement, calcium silicate, clay, aluminum silicate, sodium aluminum silicate, aluminopolysilicate, alumina silica gel, glass particles, carbon black, activated carbon, carbon fiber, charcoal, graphite, titanium oxide, iron oxide, copper oxide, zinc oxide, lead oxide, tungsten, antimony oxide, zirconium oxide, magnesium oxide, aluminum oxide, molybdenum disulfide, zinc sulfide, barium sulfate, strontium sulfate, calcium carbonate, magnesium carbonate, and various combinations thereof;

the battery separator further comprises a surfactant or additive, preferably a surfactant comprising an alkyl sulfate; an alkyl aryl sulfonate; alkylphenol-alkylene oxide addition products; a soap; alkyl-naphthalene sulfonates; dialkyl esters of sulfosuccinates; a quaternary amine; block copolymers of ethylene oxide and propylene oxide; and salts of monoalkyl and dialkyl phosphates; preferred additives include one or more latex additives; preferred such additives are nonionic surfactants including polyol fatty acid esters, polyethoxylated fatty alcohols, alkyl polysaccharides such as alkyl polyglycosides and mixtures thereof, amine ethoxylates, sorbitan fatty acid ester ethoxylates, organosilicone-based surfactants, ethylene vinyl acetate terpolymers, ethoxylated alkyl aryl phosphate esters, and sucrose esters of fatty acids;

the separator comprises rows of serrated ribs, interrupted ribs, dimples or combinations thereof, wherein the rows are spaced 0.1-20mm apart; and/or

The battery is in motion; and the motion provides energy for enhanced or improved acid mixing.

7. The flooded lead acid battery of any one of claims 1 to 5,

the flooded lead acid battery is a start/stop flooded lead acid battery;

the flooded lead acid battery is an enhanced flooded lead acid battery;

the flooded lead-acid battery does not generate acid stratification when in use;

the flooded lead acid battery has improved uniformity and performance compared to previously available flooded lead acid batteries; and/or

The performance of the flooded lead acid battery can reach or exceed that of at least a VRLA-AGM battery.

8. A method of reducing acid stratification in a battery comprising the steps of:

providing an alternating sequence of positive and negative electrodes;

providing a separator between each electrode; and

immersing an electrode in a liquid electrolyte, wherein a difference in electrolyte density between a top and a bottom of the flooded lead acid battery is less than 50% after the flooded lead acid battery has undergone 30, 60, or 90 start/stop cycles.

9. A method of testing a battery to reduce acid stratification by introducing acceleration and deceleration motions to promote acid mixing in the presence of an acid mixing separator, wherein the difference in electrolyte density between the top and bottom of a flooded lead acid battery is less than 50% after the flooded lead acid battery has undergone 30, 60, or 90 start/stop cycles.

10. A reduced weight battery separator that reduces acid displacement allowing more available electrolyte between the electrodes, wherein the difference in electrolyte density between the top and bottom of a flooded lead acid battery is less than 50% after the flooded lead acid battery has undergone 30, 60, or 90 start/stop cycles.

11. A battery separator that improves battery conductance to allow for improved state of health and/or improved communication with an electronic device in a battery monitoring system or battery management system disposed in a vehicle or handheld monitoring device, wherein the difference in electrolyte density between the top and bottom of the flooded lead acid battery is less than 50% after the flooded lead acid battery has undergone 30, 60, or 90 start/stop cycles.