Abstract: Granules containing mixtures of silica powder and cross-linked rubber powder are used in the manufacture of battery separators or vehicle tires. A granule contains silica and rubber powders in proportional amounts that form a silica powder carrier within which rubber powder particles are distributed. Incorporating silica-rubber granules in the manufacturing process of polyethylene separators offers a way to limit water loss in and improve the cycle life of a deep cycle lead-acid battery. Incorporating silica-rubber granules in the manufacturing process of vehicle tires affords advantages including easier material handling, reduced production of dust, and reduction in the number of ingredients measured and added to the formulation.

Abstract: Proton-conducting gel electrolytes with acid immobilized within a covalently cross-linked polymer network and composites containing the gel electrolytes provide low ionic resistance, minimize acid stratification, and prevent dendrite growth. The gel electrolytes can be formed from monomers dissolved in concentrated sulfuric acid and subsequently covalently cross-linked between the battery electrodes, or the covalently cross-linked gel electrolytes can be formed in water and subsequently exchanged into sulfuric acid. The mechanical properties of these gels can often be enhanced with the addition of silica powder, silica fiber, or other additives. In some cases, the covalently cross-linked gel electrolytes are formed in the presence of a conventional silica-filled polyethylene separator or within a low density fiber mat to provide mechanical reinforcement and controlled spacing between the battery electrodes.

Abstract: Preferred embodiments of a freestanding, heat resistant microporous polymer film (10) constructed for use in an energy storage device (70, 100) implements one or more of the following approaches to exhibit excellent high temperature mechanical and dimensional stability: incorporation into a porous polyolefin film of sufficiently high loading levels of inorganic or ceramic filler material (16) to maintain porosity (18) and achieve low thermal shrinkage; use of crosslinkable polyethylene to contribute to crosslinking the polymer matrix (14) in a highly inorganic material-filled polyolefin film; and heat treating or annealing of biaxially oriented, highly inorganic material-filled polyolefin film above the melting point temperature of the polymer matrix to reduce residual stress while maintaining high porosity. The freestanding, heat resistant microporous polymer film embodiments exhibit extremely low resistance, as evidenced by MacMullin numbers of less than 4.5.

Abstract: A flexible microporous polymer sheet having first and second opposite major surfaces comprises a polymer matrix binding a filler component that exhibits high oil absorption capacity in its initial state before the start of material processing. The polymer matrix includes a polyolefin component and has three-dimensional interconnecting and interpenetrating pore and polymer networks through which the bound filler component is distributed from the first major surface to the second major surface. The polyolefin and filler components are included in amounts that result in a microporous polymer sheet having between about 75% and about 90% porosity and containing less than about 10 wt. % polyolefin component. Preferred polyolefin and filler components include ultrahigh molecular weight polyethylene and high oil absorption precipitated silica, respectively.

Abstract: Proton-conducting gel electrolytes with acid immobilized within a covalently cross-linked polymer network and composites containing the gel electrolytes provide low ionic resistance, minimize acid stratification, and prevent dendrite growth. The gel electrolytes can be formed from monomers dissolved in concentrated sulfuric acid and subsequently covalently cross-linked between the battery electrodes, or the covalently cross-linked gel electrolytes can be formed in water and subsequently exchanged into sulfuric acid. The mechanical properties of these gels can often be enhanced with the addition of silica powder, silica fiber, or other additives. In some cases, the covalently cross-linked gel electrolytes are formed in the presence of a conventional silica-filled polyethylene separator or within a low density fiber mat to provide mechanical reinforcement and controlled spacing between the battery electrodes.

Abstract: Granules containing mixtures of silica powder and cross-linked rubber powder are used in the manufacture of battery separators or vehicle tires. A granule contains silica and rubber powders in proportional amounts that form a silica powder carrier within which rubber powder particles are distributed. Incorporating silica-rubber granules in the manufacturing process of polyethylene separators offers a way to limit water loss in and improve the cycle life of a deep cycle lead-acid battery. Incorporating silica-rubber granules in the manufacturing process of vehicle tires affords advantages including easier material handling, reduced production of dust, and reduction in the number of ingredients measured and added to the formulation.

Abstract: A microporous silica-filled polyolefin separator (80) has a material composition that includes a fraction of cured rubber powder exhibiting low or no porosity. The cured rubber powder is a material derived from one or both of passenger and truck tires. The cured rubber powders exhibit the properties of increasing hydrogen evolution overpotential on the negative lead electrode and of decreasing the effect of antimony deposited on the negative electrode of the lead-acid battery. Incorporation of these cured rubber powders into the formulation of a microporous silica-filled polyethylene separator results in improved electrochemical properties in deep-cycle lead-acid batteries.

Abstract: A flexible microporous polymer sheet having first and second opposite major surfaces comprises a polymer matrix binding a filler component that exhibits high oil absorption capacity in its initial state before the start of material processing. The polymer matrix includes a polyolefin component and has three-dimensional interconnecting and interpenetrating pore and polymer networks through which the bound filler component is distributed from the first major surface to the second major surface. The polyolefin and filler components are included in amounts that result in a microporous polymer sheet having between about 75% and about 90% porosity and containing less than about 10 wt. % polyolefin component. Preferred polyolefin and filler components include ultrahigh molecular weight polyethylene and high oil absorption precipitated silica, respectively.

Abstract: A method of making a rubber-containing polyolefin separator entails preparing a pre-mixture (18) that includes polyolefin material (1), silica (2), and processing oil (5) and delivering the pre-mixture to a multi-zone extruder (12) having a sheet die (34). The pre-mixture becomes partly gelled as it advances in the extruder. Rubber powder (6) added at a medial zone (Z4) of the extruder combines with the pre-mixture advancing in the extruder to form a gelled rubber-containing extrudate as it exits the sheet die. The extrudate is processed by extracting a portion of the processing oil to form a separator sheet with dispersed rubber powder in the form of domains of larger average size. The larger rubber domains exhibit a smaller average ratio of surface area to volume and thereby results in slower release by diffusion of the beneficial substance from the rubber domains to the battery electrolyte.

Abstract: A microporous polyethylene battery separator material (212), for use in a flooded-cell type lead-acid battery, benefits from increased porosity, enhanced wettability, and exceptionally low electrical resistance when an electrolyte-soluble pore former is employed in the manufacturing process. The pore former (210) is soluble in electrolytic fluid and therefore dissolves in-situ in sulfuric acid during battery assembly. The dissolution of the pore former leaves behind additional, larger voids (220) in the separator material and thereby enhances ionic diffusion and improves battery performance.

Abstract: A microporous silica-filled polyolefin separator (80) has a material composition that includes a fraction of cured rubber powder exhibiting low or no porosity. The cured rubber powder is a material derived from one or both of passenger and truck tires. The cured rubber powders exhibit the properties of increasing hydrogen evolution overpotential on the negative lead electrode and of decreasing the effect of antimony deposited on the negative electrode of the lead-acid battery. Incorporation of these cured rubber powders into the formulation of a microporous silica-filled polyethylene separator results in improved electrochemical properties in deep-cycle lead-acid batteries.

Abstract: A microporous polyethylene battery separator material (212), for use in a flooded-cell type lead-acid battery, benefits from increased porosity, enhanced wettability, and exceptionally low electrical resistance when an electrolyte-soluble pore former is employed in the manufacturing process. The pore former (210) is soluble in electrolytic fluid and therefore dissolves in-situ in sulfuric acid during battery assembly. The dissolution of the pore former leaves behind additional, larger voids (220) in the separator material and thereby enhances ionic diffusion and improves battery performance.