Separators, batteries, battery strings with improved performance, and related methods

Patent metadata

Field	Value
Publication number	US-12113178-B2
Application number	US-201615232898-A
Country	US
Kind code	B2
Filing date	Aug 10, 2016
Priority date	Aug 10, 2015
Publication date	Oct 8, 2024
Grant date	Oct 8, 2024

Abstract

Improved battery separators are disclosed herein for use in various lead acid batteries, and in particular lead acid battery strings. The improved separators, batteries, battery strings, methods, and vehicles disclosed herein provide substantially increased battery life, substantially reduced battery fail rate, and substantially higher voltage uniformity among the various batteries in a battery string. The improved battery strings may be advantageously employed in high depth of discharge applications such as electric bicycles, golf carts (or golf cars), uninterrupted power supply (UPS) backup power battery strings, and the like.

First claim

What is claimed is:

1. A battery string comprising:
four or more monoblock valve regulated lead-acid (VRLA) batteries wired in series, wherein a total voltage of the battery string is 48 volts or greater;

each VRLA monoblock battery comprises
an alternating sequence of positive and negative electrodes, and
a separator disposed between each of the positive and negative electrodes, the separator consists of a microporous polyolefin layer including a surfactant sandwiched between a first absorptive glass mat and a second absorptive glass mat, wherein the first absorptive glass mat has a thickness from 1.0 to 3.3 mm and the second absorptive glass mat has a thickness of 0.6 mm, wherein the microporous polyolefin layer is a polyethylene layer with a ribbed or embossed backweb, a backweb thickness of the microporous polyolefin layer not including the thickness of the ribs or embossments is from 0.05 mm to 0.25 mm, and the microporous polyolefin layer with the ribbed or embossed backweb of the separator has a bi-modal pore size distribution consisting of a first region of pores consisting of larger pores having a size of 1 to 6 microns and a second region of pores consisting of smaller pores having a size of less than 0.9 micron, wherein 90% of the pores are smaller pores.

2. A battery string consisting of:
four or more monoblock valve regulated lead-acid (VRLA) batteries wired in series, wherein a total voltage of the battery string is 48 volts or greater;

each VRLA monoblock battery consists of
an alternating sequence of positive and negative electrodes, and
a separator disposed between each of the positive and negative electrodes, the separator consists of a microporous polyolefin layer including a surfactant sandwiched between a first absorptive glass mat and a second absorptive glass mat, wherein the first absorptive glass mat has a thickness from 1.0 to 3.3 mm and the second absorptive glass mat has a thickness of 0.6 mm,

wherein the microporous polyolefin layer is a polyethylene layer with a ribbed or embossed backweb, a backweb thickness of the microporous polyolefin layer not including the thickness of the ribs or embossments is from 0.05 mm to 0.25 mm, the microporous polyolefin layer with the ribbed or embossed backweb of the separator has a bi-modal pore size distribution consisting of a first region of pores consisting of larger pores having a size of 1 to 6 microns and a second region of pores consisting of smaller pores having a size of less than 0.9 micron, wherein 90% of the pores are smaller pores.

3. The battery string according to claim 1 , wherein the first absorptive glass mat and the second absorptive glass mat each comprise polymeric fibers.

4. An electric vehicle comprising a battery comprising the battery string of claim 1 .

Assignees

• Daramic Llc

Inventors

• Miller Eric H
• Wu Yanxia

Classifications

• H01M50/454

  comprising a non-fibrous layer and a fibrous layer superimposed on one another · CPC title

• H01M50/437

  Glass · CPC title

• H01M50/417

  Polyolefins · CPC title

• H01M50/463

  Separators, membranes or diaphragms characterised by their shape · CPC title

• H01M50/44

  Fibrous material · CPC title