US-12626905-B2 - Method of forming a composition and the composition formed therefrom

US12626905B2US 12626905 B2US12626905 B2US 12626905B2US-12626905-B2

Abstract

In an aspect, a method of making a composition, comprising forming a solvent mixture comprising a polymer and a solvent; precipitating the solvent mixture with a non-solvent to form the composition comprising the filler in a fibrillated polymer matrix, wherein the composition is in the form of a particulate and at least one of the solvent and the non-solvent comprises a filler; and separating the composition from the solvent and the non-solvent to isolate the composition. In another aspect, a porous material wherein the filler particles are mechanically bonded together by the polymer and wherein the polymer is present as filaments adhering to and connecting the filler particles across interstitial spaces between the filler particles. In another aspect, a precipitated polymer solution produced by a phase inversion where the majority of the liquids can be mechanically removed.

Inventors

Trevor Beard

Assignees

TEEBS R&D, LLC

Dates

Publication Date: 20260512
Application Date: 20240108

Claims (7)

1 . A method of making a porous composition, the method comprising: forming a solvent mixture comprising a polymer and a solvent; combining the solvent mixture with a non-solvent to precipitate a composition comprising a plurality of filler particles in a fibrillated polymer matrix, forming a precipitate, wherein the composition is in a form of a particulate, wherein the filler particles are mechanically bonded by one or more polymer fibers to at least one or more other(s) of the filler particles across interstitial spaces within the formed particulate, and where the polymer fibers are caused to deposit in an elongated form within the interstitial space among the filler particles having bonded filament connections to the at least one other particle, wherein at least one of the solvent and the non-solvent comprises the filler particles prior to the precipitating; removing greater than or equal to 95 percent of the solvent and the non-solvent from the composition after said precipitating of the composition and forming the precipitate; and reducing a volume of the interstitial spaces between the filler particles, resulting in a decreasing of the interstitial spaces existing within the plurality of the filler particles and the filler particles being uniformly dispersed in the composition; wherein the composition is porous and has a void content minus any liquid of 40 to 99 volume percent and a content of the filler particles of greater than or equal to 90 volume percent based on the total volume of the composition, where the filler particles are attached to the polymer or are embedded within the composition and wherein the filler particles surface area exposure to a pore is greater than or equal 50 area percent; wherein the composition comprises greater than or equal to 90 weight percent of the filler particles and 1 to 10 weight percent of the fibrillated polymer matrix based on the total weight of the composition minus any liquid; wherein an average diameter of the filler particles is less than or equal to 100 micrometers and the polymer filaments have an average diameter of 5 to 50% of the diameter of the filler particles.
2 . The method of claim 1 , wherein the removing greater than or equal to 95 percent of the solvent and non-solvent from the composition comprises: at least one of draining, screening, or filtering the precipitate, in less than or equal to 15 seconds; and drying the composition.
3 . The method of claim 1 , wherein the composition has at least one of a porosity equal to or above the tap density of the filler particles, the composition is in a form of a layer having a thickness of 0.05 to 10 millimeters, or wherein the composition is in a form that is free standing.
4 . The method of claim 1 , wherein the filler particles are spherical, irregularly shaped, agglomerates, flakes, fibers or whiskers.
5 . The method of claim 1 , wherein a function of the filler particles includes at least one of catalytic/enzymatic effect, filtration/binding property, direct chemical reaction and biological purification.
6 . A porous composition produced by the method of claim 1 .
7 . An article made from the porous composition of claim 6 , wherein the article is a filter, an insulator, a capacitor, an electrode, a battery, or a separator.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application is a Continuation application that claims the benefit of U.S. patent application Ser. No. 16/405,128 filed on May 7, 2019 and which in turn claims the benefit of U.S. Provisional Patent Application Ser. No. 62/667,799 filed May 7, 2018. The related application is incorporated herein in its entirety by reference. BACKGROUND Applications for filled polymer materials, such as battery electrodes, process equipment components, chemical detectors, sensors, filtration systems, and the like, can benefit from direct, intimate, and full surface contact between the media being treated, reacted, tested, or processed and the fillers used to achieve said processes or conversion operations. At the same time, the filled composite materials used in many of these disparate industries and operations must securely attach solid particles or powders to a binder, often a polymer material, while still allowing high surface exposure of the filler so as to achieve a high degree of interaction between the filler particles and an external fluid or media. Achieving this balance of binding the filler particles together while maintaining a high surface exposure with sufficient stand-alone structural integrity is difficult though. Typical filled composite materials have been made by various processes including solution or slurry casting, sintering, extruding, calendering, compression molding, and the like. However, these methods are largely indiscriminate in the placement of the fillers with the binder as the filler materials tend to aggregate before or during formation, resulting in encumbered access to the filler surfaces. Furthermore, these processes often produce filler materials with a thin surface layer of binder that effectively encapsulates the filler, thereby limiting access to the encapsulated filler material. The net result is that filled composite materials made using these processes can suffer from limited access to the surfaces of the filler materials, leading to a reduced performance in many applications. Battery electrodes, for example, contain filler particles (often referred to as the active material) that contact an electrolyte medium to conduct ions. Using conventional processes to form active layers for electrodes can result in a reduced surface exposure of the active material that can limit the flow of ions into and out of the respective particles due to the reduced access of the electrolyte to the active material. Additionally, the reduced surface exposure of the active material due to the presence of the binder on its surface can result in an increase in the electrical resistance of the composite, greatly reducing electron flow through or around the deposited binder, rendering a poor battery electrode. The net effect is that a battery possessing electrodes with such a reduced level of exposed surface area of active materials can have a lower rate capability (reduced power), which in turn can also effectively result in lower specific capacity (lower energy density). Post-processing operations that have been used to compress active layers in electrodes to provide a tighter packing and contact among the conductive filler particles can further compound these issues associated with poor surface exposure of the active material. For example, compression of filled composite active layers made using conventional processes, where the filler surfaces are not well exposed within or on the polymer film in the first place, can cause an additional and significant decrease in accessible surface area to the filler surfaces due to a reduction in the interstitial volume or porosity between filler particles. The decrease in accessible surface area arises as the reduction in the interstitial volume or porosity can reduce the access of the electrolyte medium to the filler materials in the composite of the electrode. Ultimately, the compression of the active layer can exacerbate the already limited access of the electrolyte medium to the active material due to collapse of the pores of the composite and the reduction in the number of pathways for ion flow, each of which can hinder battery performance. Additional drawbacks to using conventional processes to manufacture filled composite materials can include issues with solvent casting and issues with the drying processes. These issues can include a low coating thickness, a slow drying rate of solvent or diluent carrier media, and the need to reclaim or incinerate the solvents, each of which can encumber burdensome manufacturing costs. In addition, these processes can present risks for degrading the functionality of the filled composite material in the final product as a binder rich, filler deprived layer within the filled composite material near a carrier substrate can form. A process for forming a composition is therefore desired that can achieve one or more of a high filler content, a uniform filler distribution, a uniform porosity,