US 12,756,066 B2 · Solvent free separators

Abstract

This disclosure relates to battery separators for use in lead acid batteries. In particular, the disclosure relates to nonporous polymer sheets in which the porosity manifests itself after cavitation and/or biaxial stretching to form a microporous membrane. The disclosure also relates to nonporous polymer sheets in which the porosity manifests itself after dissolution of an acid soluble filler to form a microporous membrane. In addition to meeting all battery performance requirements, these microporous membranes eliminate environmental and health concerns because they do not require the use of an organic solvent during their production.

Claims20

Dependent claims

A biaxially stretched microporous membrane, comprising:

isotactic polypropylene having a melt flow index of 0.5 to 5 g/10 min, the isotactic polypropylene forming 60-80 wt % of the microporous membrane;
an inorganic filler forming 5-25 wt % of the microporous membrane;
a surfactant forming 2-20 wt % of the microporous membrane;
and
a plasticizer or process oil forming 5-20 wt % of the microporous membrane,
wherein the microporous membrane is formed with a stretch ratio of at least 2.0 in either a machine direction, a transverse direction, or both, and
wherein the microporous membrane comprises a porosity of greater than 50%.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application

18/250,491Filed 11 Nov 2021 · us provisional application

Priority

11 Nov 2020

Published

US 2023/0395937 A17 Dec 2023

Granted

6 Oct 2026

Term ends

Not estimatedThe source records don’t support an estimate.

Classification6 codes

H01M 50/446
Separators, membranes or diaphragms characterised by the material: composite material consisting of a mixture of organic and inorganic materials
H01M 50/403
Separators; Membranes; Diaphragms; Spacing elements inside cells: manufacturing processes of separators, membranes or diaphragms
H01M 50/417
Synthetic resins, e.g. thermoplastics or thermosetting resins: polyolefins
H01M 50/463
Separators; Membranes; Diaphragms; Spacing elements inside cells: separators, membranes or diaphragms characterised by their shape

Solvent free separators

Life of this patent

Solvent free separators

Life of this patent

Abstract

Claims20