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

Patent metadata

Field	Value
Publication number	US-2017054123-A1
Application number	US-201615232898-A
Country	US
Kind code	A1
Filing date	Aug 10, 2016
Priority date	Aug 10, 2015
Publication date	Feb 23, 2017
Grant date	—

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:
two or more monoblock VRLA batteries wired in series, wherein a total voltage of the battery string is at least 12 volts; each monoblock battery comprises an alternating sequence of positive and negative electrodes, a separator is disposed between each of the electrodes, the separator comprises a microporous polyolefin layer and at least one layer comprising one or more fibrous materials; and the battery string exhibits improved voltage uniformity and cycle life when compared with a battery string comprising a conventional AGM battery separator.

2 . The battery string according to claim 1 , wherein the microporous polyolefin layer comprises one or more polyolefins and a filler.

3 . The battery string according to claim 1 , wherein the microporous polyolefin layer comprises polyethylene.

4 . The battery string according to claim 1 , wherein the fibrous material comprises glass fibers.

5 . The battery string according to claim 1 , wherein the fibrous material comprises polymeric fibers.

6 . The battery string according to claim 1 , wherein the microporous polyolefin layer is flat.

7 . The battery string according to claim 1 , wherein the microporous polyolefin layer is ribbed, embossed, and/or textured.

8 . The battery string according to claim 1 , wherein the microporous polyolefin layer further comprises a surfactant or an additive.

9 . The battery string according to claim 8 , wherein the surfactant comprises a non-ionic surfactant.

10 . The battery string according to claim 8 , wherein the surfactant or additive suppresses an overcharge potential for one or more of the monoblock batteries and/or decreases grid corrosion occurring for one or more of the monoblock batteries.

11 . The battery string according to claim 1 , wherein the improved cycle life includes cycle life improvement of at least 30% for said battery string when compared with a battery string comprising the conventional AGM battery separator.

12 . The battery string according to claim 1 , wherein the improved voltage uniformity includes voltage uniformity improvement of at least two times the voltage uniformity of a battery string comprising the conventional AGM battery separator.

13 . The battery string according to claim 1 , wherein each monoblock battery is a 6-volt, 8-volt, or 12-volt monoblock battery.

14 . An electric bicycle battery comprising the battery string of claim 1 .

15 . An electric bicycle comprising the electric bicycle battery of claim 14 .

16 . An electric vehicle battery comprising the battery string of claim 1 , wherein the electric vehicle is selected from the group consisting of: an e-bike, a motive power vehicle, an e-car, a golf cart, a fork truck, a pallet jack, and a scissor lift.

17 . A deep cycling uninterrupted power supply (UPS) backup power battery comprising the battery string of claim 1 .

18 . A method of improving a battery string comprising the steps of:
providing a battery string comprising two or more monoblock VRLA batteries wired in series, wherein a total voltage of the battery string is at least 12 volts; providing each monoblock VRLA battery with an alternating sequence of positive and negative electrodes; providing a separator between each of the electrodes, the separator comprises a microporous polyolefin layer and at least one layer comprising one or more fibrous materials; and cycling the battery string through charge and discharge cycles, the battery string exhibits improved voltage uniformity during cycling and improved cycle life when compared with a known battery string comprising a conventional AGM battery separator.

19 . A composite separator for a battery string comprising at least one glass mat and at least one porous polymer membrane comprising a microporous polyolefin layer as shown or described herein.

20 . The separator of claim 19 , wherein the at least one porous polymer membrane comprising the microporous polyolefin layer as shown or described in FIG. 4 herein.

21 . In a battery for a battery string, the improvement comprising the separator of claim 19 .

22 . The battery of claim 21 , wherein the battery is for a battery string in high depth of discharge applications such as electric bicycles, golf carts (or golf cars), uninterrupted power supply (UPS) backup power, and the like.

23 . In a vehicle or power supply, the improvement comprising the battery of claim 21 .

Assignees

• Daramic Llc

Inventors

• Miller Eric H
• Wu Yanxia

Classifications

• H01M10/121 Primary

  Valve regulated lead acid batteries [VRLA] · CPC title

• H01M50/454

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

• H01M50/417

  Polyolefins · CPC title

• H01M50/437

  Glass · CPC title

• H01M10/14

  Assembling a group of electrodes or separators · CPC title