Abstract: Electrode assemblies for use in electrochemical cells are provided. The negative electrode assembly includes negative electrode active material and an electrolyte chosen specifically for its useful properties in the negative electrode. Such properties include reductive stability and ability to accommodate expansion and contraction of the negative electrode active material. Similarly, the positive electrode assembly includes positive electrode active material and an electrolyte chosen specifically for its useful properties in the positive electrode. These properties include oxidative stability and the ability to prevent dissolution of transition metals used in the positive electrode active material. A third electrolyte can be used as separator between the negative electrode and the positive electrode. A cell is constructed with a cathode that includes a fluorinated electrolyte which does not penetrate into the solid-state polymer electrolyte separator between it and the lithium-based anode.

Abstract: The present application provides a lithium-ion battery, which comprises: a wound-type cell formed by winding a positive electrode plate, a separator and a negative electrode plate, a width of the separator is greater than widths of the positive electrode plate and the negative electrode plate; an electrolyte; and a packaging film packaging the wound-type cell and accommodating the electrolyte; a wound ending of the wound-type cell is adhered with a single-sided adhesive layer, an adhesive of the single-sided adhesive layer is a flowable curing adhesive, the wound-type cell and the packaging film are adhered together by the curing adhesive which flows and flows out from a periphery of the single-sided adhesive layer. The single-sided adhesive layer can prevent the wound-type cell from loosening or deforming, rupturing of the positive electrode tab and the negative electrode tab and bursting open of a top-seal in the process of dropping or tumbling.

Abstract: In general, techniques are described for filter media monitoring within a filtration system. The filter media monitoring techniques described herein include, for example, direct contact with the filter media, e.g., a sensor may be located inside a boundary defined by a surface of the filter media, or indirect contact with the filter media, e.g., a sensor may be located outside the boundary defined by the surface of the filter media such that the sensor does not make direct physical contact with the filter media being monitored.

Abstract: A separator for a lithium-ion battery includes a substrate, a coating, and a middle layer formed between the substrate and the coating. The middle layer includes a part of the substrate and a part of the coating. The substrate contains a base polymer, a first polymer, and a first inorganic material. The coating contains a second polymer and a second inorganic material. The first polymer and the second polymer independently contain an acid radical in a side chain thereof. The first inorganic material is reactive with the first polymer via a first neutralization reaction, and the second inorganic material is reactive with the second polymer via a second neutralization reaction. A method for preparing a separator for a lithium-ion battery and a lithium-ion battery are also provided.

Abstract: A non-aqueous electrolyte secondary battery includes battery element formed by laminating and winding positive electrode and negative electrode via separator. Positive electrode includes a positive electrode current-collector-exposed portion, in which the positive electrode current collector is exposed over a length dimension of not less than one turn of the winding of battery element in the outermost circumference and an intermediate layer portion of the winding. The negative electrode in a part facing the positive electrode current collector exposed in the intermediate layer portion includes the negative electrode active material layer laminated on the negative electrode current collector. Negative electrode can be provided with a slit at an exposed side with respect to both exposed ends of the positive electrode current-collector-exposed portion.

Abstract: Provided are a polymer electrolyte, a lithium secondary battery using the same, and a manufacturing method thereof, in which a gel polymer electrolyte is formed from a monomer for forming a gel polymer by a rapid polymerization reaction, when using a porous nanofiber web as an electrolyte matrix, and injecting an organic electrolytic solution formed by mixing the gel polymer forming monomer and a polymerization initiator, to induce an addition polymerization reaction, but the porous nanofiber web maintains a web-like shape. The polymer electrolyte includes: a separator made of a porous nanofiber web having a plurality of nanofibers; and a gel polymer portion impregnated in the porous nanofiber web. the gel polymer portion is formed by impregnating an electrolytic solution containing a non-aqueous organic solvent, a lithium salt solute, a gel polymer forming monomer, and a polymerization initiator in the porous nanofiber web and polymerizing the gel polymer forming monomer.

Abstract: A lithium-ion secondary battery with a high capacity retention rate is provided. In addition, a fabricating method of a lithium-ion secondary battery with a high capacity retention rate is provided. The lithium-ion secondary battery includes a positive electrode, a negative electrode, and an electrolyte solution. The negative electrode includes a negative electrode active material layer. The electrolyte solution includes at least one of lithium bis(trifluoromethanesulfonyl)amide (LiTFSA) and lithium bis(fluorosulfonyl)amide (LiFSA). The electrolyte solution includes vinylene carbonate (VC). A coating film including lithium oxide is on a surface of the negative electrode active material layer.

Abstract: A positive electrode for a lithium secondary battery is described which includes a lithium transition metal complex oxide including a lithium nickel based complex oxide and/or a lithium cobalt based complex oxide, active carbon having a specific surface area of from about 900 m2/g to about 1600 m2/g, and a water-based binder.

Abstract: A battery including an electrode assembly is provided. The electrode assembly has first and second current collectors facing region disposed at a winding start end and at a winding terminal end, respectively. A positive electrode current collector exposed portion and a negative electrode current collector exposed portion face each other through the separator in each of the first and second current collector facing regions. At least one of the positive or negative electrode current collector exposed portion has a first insulating member formed thereon in the first current collector facing region at the winding start end and has a second insulating member formed thereon in the second current collector facing region at the winding terminal end. The second insulating member has a melting point lower than that of the first insulating member.

Abstract: An energy storage device includes: a core; and a wound body including, layered and wound around the core: a positive electrode, a negative electrode, and two separators, one of which is interposed between the positive electrode and the negative electrode and each having a first surface and a second surface. The first surface has thermal bonding properties superior to thermal bonding properties of the second surface, and at least one of the two separators is bonded to the core via the first surface thereof.

Abstract: The present invention provides a separator roll (10) and the like including a core suited for reuse. The separator roll (10) includes: a porous separator (12) for use in a battery; and a core (8) around which the separator (12) is wound. The outer circumferential surface (S) of the core (8) has arithmetic mean roughness of not less than 3.7 ?m, the outer circumferential surface (S) being in contact with the separator (12).

Abstract: A non-aqueous electrolyte secondary battery is capable of suppressing a local reaction of a negative electrode active material due to the electrolyte during charging and discharging and improving a capacity retention ratio of a using a carbon material such as artificial graphite particles for the negative electrode active material. The non-aqueous electrolyte secondary battery includes a negative electrode containing a carbon-based negative electrode active material, an electrolyte layer, and a positive electrode containing a positive electrode active material, and having a tap density of the negative electrode active material of 0.96 g/cc or more.

Abstract: The present invention relates to a polymer resin composition including: one or more copolymers selected from the group consisting of an unsaturated nitrile-diene-based rubber-aromatic vinyl graft copolymer, an alkyl methacrylate-diene-based rubber-aromatic vinyl graft copolymer, and an alkyl methacrylate-silicone/alkyl acrylate graft copolymer; a polyester resin; a polycarbonate resin; and a block copolymer including two or more alkylene-based repeating units having 2 to 10 carbon atoms and an aromatic vinyl-based repeating unit, and a molded article thereof. According to the present invention, a polymer resin composition providing an environment-friendly biomass-containing synthetic resin representing improved chemical resistance, and a polymer resin molded article obtained using the same may be provided.

Abstract: A method for producing a domestic appliance plate from a starting mixture. In order to provide a domestic appliance plate having a high resistance to thermal shock, good thermal insulation, and advantageous mechanical properties, at least magnesium silicate hydrate, kaolinite, calcined kaolinite, and aluminum oxide are used for the starting mixture.

Abstract: A method for charging a lithium ion secondary battery including at least a positive electrode, a negative electrode provided with a negative electrode active material layer that includes carbon as a negative electrode active material, an electrolytic solution, and a sheathing material that encloses the positive electrode, the negative electrode and the electrolytic solution; the negative electrode active material layer including carboxymethyl cellulose and the electrolytic solution including an additive that can be decomposed at a predetermined voltage includes: preliminary charging including constant-current charging in which charging is performed at a fixed current value and, following the constant-current charging, constant-voltage charging in which charging is performed at a fixed voltage; degassing in which gas is removed from within the sheathing material after the preliminary charging; and main charging that follows the degassing in which the lithium ion secondary battery is charged.

Abstract: A method for connecting electrodes of the same polarity of an accumulator (1) to a current output terminal (6, 7), the accumulator including two current output terminals (6, 7), a container (2) containing an electrochemical bundle (9) having alternating positive and negative electrodes, the ends of the current collectors of the positive and negative electrodes defining a first (Si) and second (S2) surface respectively. There is a step of additive manufacturing of an internal connecting part (11, 13) electrically connecting the first and/or the second surface to the corresponding current output terminal.

Abstract: A porous membrane is provided including a compound having a hydrophobic group and a nonionic hydrophilic group, an inorganic powder, and a binder resin.

Abstract: A method of manufacturing a separator for an electrochemical device according to an exemplary embodiment of the present disclosure includes extruding a resin composition including polyolefin and a diluent, stretching the extruded resin composition to obtain a polyolefin film, extracting the diluent from the obtained polyolefin film to obtain a porous polyolefin film, coating a slurry for forming a porous coating layer on at least one surface of the porous polyolefin film, and heat setting the porous polyolefin film coated with the slurry to obtain a composite separator with a porous coating layer.

Abstract: A novel hybrid lithium-ion anode material based on coaxially coated Si shells on vertically aligned carbon nanofiber (CNF) arrays. The unique cup-stacking graphitic microstructure makes the bare vertically aligned CNF array an effective Li+ intercalation medium. Highly reversible Li+ intercalation and extraction were observed at high power rates. More importantly, the highly conductive and mechanically stable CNF core optionally supports a coaxially coated amorphous Si shell which has much higher theoretical specific capacity by forming fully lithiated alloy. Addition of surface effect dominant sites in close proximity to the intercalation medium results in a hybrid device that includes advantages of both batteries and capacitors.

Abstract: The present invention relates to a battery module. The battery module includes a battery cell, a module case in which the battery cell is built, and a flame retardant filled in the module case. Thus, when the battery module is damaged, an insulation film is formed on the damaged portion to prevent fire or explosion from occurring.

Abstract: A wrinkle or misaligned winding caused in a separator roll is inhibited. In a slitting apparatus (6), a conveying direction of a first separator (12a) is changed to a first take-up roller (70U) side by a direction changing roller (68), the first separator is conveyed via a take-up assisting roller (69) which is provided between the direction changing roller and a first touch roller (81U) so as to shorten a roller-to-roller distance to the first touch roller, and the first separator which is being wound is pressed onto a take-up surface by the first touch roller.

Abstract: A lithium secondary battery which has high charge-discharge capacity, can be charged and discharged at high speed, and has little deterioration in battery characteristics due to charge and discharge is provided. A negative electrode includes a current collector and a negative electrode active material layer. The current collector includes a plurality of protrusion portions extending in a substantially perpendicular direction and a base portion connected to the plurality of protrusion portions. The protrusion portions and the base portion are formed using the same material containing titanium. A top surface of the base portion and at least a side surface of the protrusion portion are covered with the negative electrode active material layer. The negative electrode active material layer may be covered with graphene.

Abstract: An embodiment of the present invention relates to a lithium secondary battery comprising a nonaqueous electrolytic solution comprising a phosphate compound represented by the following general formula (1): O?P(O—R1)(O—R2)(O—R3) (1), wherein R1, R2, and R3 are each alkyl group or the like or a group comprising an ether bond represented by —R4—O—R5 (R4 represents alkylene group, and R5 represents alkyl group), and at least one of R1, R2, and R3 is a group comprising an ether bond, and at least one of R1, R2, and R3 contains fluorine, and a positive electrode active material having a charge and discharge region of 4.5 V or more versus lithium.

Abstract: An electrode wound element for a non-aqueous electrolyte rechargeable battery includes a belt-shaped positive electrode; a belt-shaped negative electrode; a belt-shaped porous layer between the belt-shaped positive electrode and the belt-shaped negative electrode; and an adhesive layer formed on the surface of the belt-shaped porous layer, wherein the adhesive layer includes a fluorine resin-containing particulate; a binder supporting the fluorine resin-containing particulate and having a total volume which is that of the fluorine resin-containing particulate; and a heat-resistance filler particle showing a filling ratio of about 40% or greater when being compressed with about 1 MPa.

Abstract: The present invention relates to a separator for an electrochemical cell, preferably a lithium ion battery, comprising a porous layer which comprises at least one block copolymer having three or more polymer blocks and at least one aluminum oxide or hydroxide, a lithium ion battery comprising such a separator, and a method for producing such a separator.

Abstract: The present specification provides a polymer electrolyte membrane, a membrane electrode assembly including the polymer electrolyte membrane, and a fuel cell including the membrane electrode assembly.

Abstract: A novel hybrid lithium-ion anode material based on coaxially coated Si shells on vertically aligned carbon nanofiber (CNF) arrays. The unique cup-stacking graphitic microstructure makes the bare vertically aligned CNF array an effective Li+ intercalation medium. Highly reversible Li+ intercalation and extraction were observed at high power rates. More importantly, the highly conductive and mechanically stable CNF core optionally supports a coaxially coated amorphous Si shell which has much higher theoretical specific capacity by forming fully lithiated alloy. Addition of surface effect dominant sites in close proximity to the intercalation medium results in a hybrid device that includes advantages of both batteries and capacitors.

Abstract: The invention relates to solid-state electrolytes for use in lithium-air batteries or in lithium-water batteries. It is the object of the invention to provide solid electrolyte for use in lithium-air batteries or lithium-water batteries, with the solid electrolyte having sufficient strength, good conductivity for lithium ions, imperviousness for gas and water resistance and being inexpensive in manufacture. The solid-state electrolyte in accordance with the invention has an open-pore ceramic carrier substrate. In this respect, at least one layer which is conductive for lithium ions, which has an electrical conductivity of at least 10?5 Scm?1 and which is gas-impervious is formed on the surface facing the cathode. In this respect, the carrier substrate has greater mechanical strength and a larger layer thickness than the at least one layer.

Abstract: A method of producing a lithium ion secondary battery includes: selecting a positive electrode active material that has a prescribed specific surface area, and preparing a nonaqueous electrolyte solution that contains a compound with a following formula (1) at a prescribed concentration. In an xy-coordinate plane that gives a relationship between a specific surface area x [m2/g] of the positive electrode active material and a concentration y [mol/kg] of the compound in the nonaqueous electrolyte solution, a combination of the prescribed specific surface area and the prescribed concentration corresponds to a combination of values that lies within a hexagonal inner region formed by connecting 6 points (x, y)=(1.50, 0.050), (2.20, 0.05), (2.60, 0.10), (2.60, 0.16), (0.80, 0.16), and (0.60, 0.10) in this sequence with straight lines.

Abstract: Provided is a method for producing a separator which method less causes a tear in the separator. The method is a method for producing a separator by slitting, in a direction in which a separator original sheet (12b) being porous is conveyed, the separator original sheet (12b) into a plurality of separators (12a), including the steps of: (a) conveying the separator original sheet (12b) in a state where the separator original sheet (12b) is in contact with a roller (77); and (b) slitting the separator original sheet (12b) at a portion where the separator original sheet (12b) is in contact with the roller (77).

Abstract: A novel hybrid lithium-ion anode material based on coaxially coated Si shells on vertically aligned carbon nano fiber (CNF) arrays. The unique cup-stacking graphitic microstructure makes the bare vertically aligned CNF array an effective Li+ intercalation medium. Highly reversible Li+ intercalation and extraction were observed at high power rates. More importantly, the highly conductive and mechanically stable CNF core optionally supports a coaxially coated amorphous Si shell which has much higher theoretical specific capacity by forming fully lithiated alloy. Addition of surface effect dominant sites in close proximity to the intercalation medium results in a hybrid device that includes advantages of both batteries and capacitors.

Abstract: An electrode assembly and a rechargeable battery that can prevent an active material from separating and prevent a short circuit and damage due to a tab that is attached to a current collector are provided. The electrode assembly includes a positive electrode, a negative electrode, and a separator that is disposed between the positive electrode and the negative electrode. The positive electrode has a positive electrode coating portion in which a positive electrode active material layer is formed and a positive electrode uncoated region in which a positive electrode active material layer is not formed, and a positive electrode tab is attached to the positive electrode uncoated region.

Abstract: Disclosed herein is a rechargeable battery capable of maintaining alignment among a positive electrode, a negative electrode, and a separator of an electrode assembly even in the case in which a form thereof is changed or bent. The rechargeable battery includes: an electrode assembly formed by stacking a first electrode, a separator, and a second electrode, and having an alignment groove formed therein; a case having flexibility and accommodating the electrode assembly therein; and an alignment guide protruding from the case and partially coupled to the alignment groove so as to accommodate and guide a change in a length of the electrode assembly depending on bending.

Abstract: Provided are separators for use in an electrochemical cell comprising (a) an inorganic oxide and (b) an organic polymer, wherein the inorganic oxide comprises organic substituents. Also provided are electrochemical cells comprising such separators.

Abstract: A battery module includes a plurality of battery cells aligned in one direction, each battery cell of the plurality of battery cells including a terminal portion on a first surface of a respective battery cell, a bus-bar electrically connect between the terminal portions of the plurality of battery cells, and a bus-bar holder positioned on the first surfaces of the plurality of battery cells, the bus-bar holder including support portions configured to support two different surfaces of the bus-bar, respectively.

Abstract: This invention provides a novel battery structure that, in some variations, utilizes a mixed lithium-ion and electron conductor as part of the separator. This layer is non-porous, conducting only lithium ions during operation, and may be structurally free-standing. Alternatively, the layer can be used as a battery electrode in a lithium-ion battery, wherein on the side not exposed to battery electrolyte, a chemical compound is used to regenerate the discharged electrode. This battery structure overcomes critical shortcomings of current lithium-sulfur, lithium-air, and lithium-ion batteries.

Abstract: Provided are a bi-cell for a secondary battery having improved stability which may reduce shrinkage of a separator, and a method of preparing the bi-cell. The bi-cell for a secondary battery having improved stability according to an exemplary embodiment of the present invention is characterized in that a cathode and an anode are alternatingly disposed in a state in which the cathode has one more layer than the anode or the anode has one more layer than the cathode, separators having a bigger size than the cathode and the anode and insulating the cathode and the anode are disposed between the cathode and the anode, and edges of an upper separator and edges of a lower separator, which face to each other having the cathode and the anode disposed therebetween, are attached to each other to form fused portions.

Abstract: The following disclosure relates to a microporous polyolefin composite film having excellent heat resistance and thermal stability, and a method for manufacturing the same. More particularly, the present invention relates to a microporous polyolefin composite film capable of improving stability and reliability of a battery by heat sealing an edge of a microporous film provided with a coating layer that includes a polymer binder and inorganic particles, and a method for manufacturing the same.

Abstract: An electric storage device includes an electrolyte and an electric storage unit including a positive electrode including a positive-electrode collector electrode and a positive-electrode active-material layer disposed on the positive-electrode collector electrode; a negative electrode including a negative-electrode collector electrode and a negative-electrode active-material layer disposed on the negative-electrode collector electrode and facing the positive-electrode active-material layer; a first insulating layer bonded to the positive electrode and the negative electrode to isolate the positive electrode and the negative electrode from each other; and a region that is sealed with the first insulating layer in plan view and that holds the electrolyte between the positive electrode and the negative electrode, wherein an air permeability P of the first insulating layer satisfies the formula 1250 s/100 cc<P<95000 s/100 cc.

Abstract: A method may involve forming a first electrode on a structure, where the first electrode defines an anode of a battery, and where the battery is configured to provide electrical power to a circuit located on the structure. The method may further involve forming a second electrode on the structure, where the second electrode defines a cathode of the battery, and where the second electrode is configured to reduce oxygen. And the method may involve embedding the structure in a polymer.

Abstract: A spirally-wound electrode assembly for a rechargeable lithium battery includes a positive electrode, a negative electrode and a separator between the positive electrode and the negative electrode, wherein the separator includes a porous film and an adhesive layer on at least one side of the porous film, and the adhesive layer includes a fluorine-based polymer-containing particulate and a binder. A rechargeable lithium battery includes the spirally-wound electrode assembly.

Abstract: To provide a method for producing an electrode/separator laminate which, when producing the electrode/separator laminate by subjecting the electrode and separator with adhesive layer to thermocompression bonding, the separator and the electrode can be bonded with adequate adhesion, without detriment to ion conductivity. [Solution] This method for producing an electrode/separator laminate includes a step in which a separator with adhesive layer comprising a porous polyolefin film having an adhesive layer at least on one side, and an electrode which has an electrode active substance layer containing an electrode active substance and an electrode binder, are laminated in such a manner that the adhesive layer and the electrode active substance layer touch one another, and are subsequently subjected to thermocompression.

Abstract: A non-aqueous electrolyte secondary battery includes a positive electrode composite material layer containing first positive electrode active material particles containing a lithium nickel composite oxide, second positive electrode active material particles containing lithium iron phosphate, and a conductive material. A ratio of the second positive electrode active material particles in a total mass of the first positive electrode active material particles and the second positive electrode active material particles is not lower than 5 mass % and not higher than 20 mass %. A standard deviation ? representing distribution of an iron element satisfies a condition of 0.28???0.52 when distribution of the iron element is determined by conducting area analysis with an electron probe microanalyzer in a cross-section of the positive electrode composite material layer.

Abstract: A good-quality slit separator having a small amount of fuzziness at a slit part thereof is to be obtained. The present invention includes: a step (S101) of conveying an original sheet (S); and a step (S102) of slitting the original sheet (S) by causing a slitting blade (72) to cut into the original sheet (S) such that a d tangent plane angle (?3) in a tangent plane, on which a slitting position is in contact with the original sheet (S), is in a range of not less than 3° to not more than 35°.

Abstract: An electrode assembly according to an embodiment of the present invention includes a first electrode plate having a fist electrode tab at an end of one side thereof, a second electrode plate having a second electrode tab, which is formed in a same direction as a longitudinal direction of the first electrode tab and is formed at a position not overlapping the first electrode tab, and a protrusion which is formed at a position overlapping the first electrode tab, and a separator insulating the first electrode plate and the second electrode plate. Therefore, the electrode assembly according to the embodiment of the present invention and the secondary battery including the same may improve the stability of the secondary battery by preventing lithium ion accumulation in a separator.

Abstract: This invention provides a lithium secondary battery comprising a positive electrode, a negative electrode, and a non-aqueous electrolyte. On the negative electrode surface, there is present a cyclic siloxane and/or a reaction product thereof. The cyclic siloxane is a cyclic siloxane having at least one side chain comprising a dimethylsiloxy group (a siloxy side chain-containing cyclic siloxane).

Abstract: An objective of the invention is to provide a method for producing an all-solid-state battery with fewer steps for minimizing warping than in the prior art, and an all-solid-state battery with lower warping. This is achieved by a method comprising the steps of: (A) disposing a first electrode active material layer on both sides of a first collector to form a first electrode layer, (B) disposing a solid electrolyte layer on each of the first electrode active material layers, (C) disposing a second electrode active material layer and a second collector on the solid electrolyte layers, in such a manner that the second electrode active material layers contact with the solid electrolyte layers, (D) pressing a stack formed in steps (A) to (C), to form a battery unit, (E) repeating steps (A) to (D) to form a plurality of battery units, and (F) stacking the plurality of battery units.

Abstract: A reactive separator is provided for a metal-ion battery. The reactive separator is made up of a reactive layer that is chemically reactive to alkali or alkaline earth metals, and has a first side and a second side. A first non-reactive layer, chemically non-reactive with alkali or alkaline earth metals, is adjacent to the reactive layer first side. A second non-reactive layer, also chemically non-reactive with alkali or alkaline earth metals, is adjacent to the reactive layer second side. More explicitly, the first and second non-reactive layers are defined as having less than 5 percent by weight (wt %) of materials able to participate in electrochemical reactions with alkali or alkaline earth metals. The reactive layer may be formed as a porous membrane embedded with reactive components, where the porous membrane is carbon or a porous polymer. Alternatively, the reactive layer is formed as a polymer gel embedded with reactive components.

Abstract: A rechargeable lithium battery includes an electrode assembly including a positive electrode, a first separator, a negative electrode, and a second separator that are sequentially stacked. The first separator includes a first substrate including a first side facing the positive electrode and a second side facing the negative electrode. The second separator includes a second substrate including a third side facing the negative electrode and a fourth side facing the positive electrode. At least one of the first side to the fourth side includes an organic layer including an organic material, and at least one of the second side or the third side includes an inorganic layer including an inorganic material.

Abstract: A porous polymer battery separator includes variable porosity along its length and can increase the uniformity of the current density within electrochemical battery cells that may normally experience higher current density and higher temperatures near their terminal ends than they do near their opposite ends. By disposing a variable porosity separator between the electrodes of an electrochemical cell such that its terminal end has a lower porosity than its opposite end, the transport of ions through the separator can be more restricted in normally high current regions and less restricted in normally low current regions, thereby increasing the overall uniformity of current density within the cell. The separators may be produced by a dry-stretching process or by a wet process. These processes may include forming a polymer-containing film, producing a uniform distribution of pore sites within the film, and reforming the polymer-containing film to a uniform thickness.