Electrochemical cell separator

Patent metadata

Field	Value
Publication number	US-2019393469-A1
Application number	US-201916438979-A
Country	US
Kind code	A1
Filing date	Jun 12, 2019
Priority date	Jun 20, 2018
Publication date	Dec 26, 2019
Grant date	—

Abstract

The discharge performance of a primary, bobbin-style electrochemical cell is improved by incorporating a separator formed from a continuous separator sheet defining a two-layer cylindrical sidewall and a closed bottom end between the included electrochemical cell cathode and anode. A first layer of the cylindrical separator is formed by rolling a first end of a continuous separator sheet into a cylinder having a central axis parallel with a longitudinal axis of the continuous separator sheet, and then rolling a second end of the continuous separator sheet around the exterior of the first cylindrical layer to form a second cylindrical layer. The closed bottom end is formed by a portion of the continuous separator sheet located between the rolled portion of the first end and the rolled portion of the second end.

First claim

That which is claimed:

1 . A method of manufacturing an electrochemical cell, the method comprising:
providing a cylindrical electrochemical cell can having an active material ring disposed proximate an interior surface of the cell can; forming a cylindrical separator comprising a continuous separator sheet defining (a) a closed bottom end and (b) a two-layer cylindrical sidewall; inserting the cylindrical separator end into the interior of the active material ring; disposing a second active material within an interior of the separator; and sealing the electrochemical cell can.

2 . The method of manufacturing an electrochemical cell of claim 1 , wherein forming the cylindrical separator comprises forming a seam for each of the two layers of the cylindrical sidewall, wherein the seams are aligned with a diameter of the cylindrical sidewall.

3 . The method of manufacturing an electrochemical cell of claim 2 , wherein forming the cylindrical separator comprises:
forming a first end of the continuous separator sheet into a first cylindrical layer; and forming a second end of the continuous separator sheet, opposite from the first end, into a second cylindrical layer around an exterior of first cylindrical layer.

4 . The method of manufacturing an electrochemical cell of claim 3 , wherein:
forming the first end of the continuous separator sheet into a first cylindrical layer comprises rolling opposite longitudinal edges of the first end of the continuous separator sheet to meet at a first seam; and forming the second end of the continuous separator sheet into a second cylindrical layer comprises rolling opposite longitudinal edges of the second end of the continuous separator sheet to meet at a second seam.

5 . The method of claim 4 , wherein the first seam and the second seam are aligned on opposite sides of a central axis of the cylindrical separator.

6 . The method of manufacturing an electrochemical cell of claim 1 , further comprising positioning a separator reinforcement layer adjacent the closed bottom end of the cylindrical separator.

7 . The method of manufacturing an electrochemical cell of claim 6 , wherein positioning a separator reinforcement layer adjacent the closed bottom end comprises positioning a reinforcing cup adjacent a bottom exterior surface of the closed bottom end.

8 . An electrochemical cell comprising:
a container; a ring-shaped cathode disposed within the container wherein the cathode includes an exterior surface in contact with the container and an interior surface surrounding a hollow interior; an anode disposed within the hollow interior of the cathode; and a separator positioned between the cathode and the anode, wherein the separator comprises a continuous separator sheet defining (a) a closed bottom end and (b) a two-layer cylindrical sidewall.

9 . The electrochemical cell of claim 8 , wherein the cylindrical separator comprises a seam within each of the two layers of the cylindrical sidewall, wherein the seams are aligned with a diameter of the cylindrical sidewall.

10 . The electrochemical cell of claim 9 , wherein:
a first layer of the cylindrical separator is formed from a first end of the continuous separator sheet; and a second layer of the cylindrical separator is formed from a second end of the continuous separator sheet, rolled around an exterior surface of the first layer of the cylindrical separator sheet.

11 . The electrochemical cell of claim 10 , wherein:
the first end of the continuous separator sheet is rolled into a first cylindrical layer such that opposing longitudinal edges of the first end of the continuous separator sheet meet at a first seam; and the second end of the continuous separator sheet is rolled around the first cylindrical layer such that opposing longitudinal edges of the second end of the continuous separator sheet meet at a second seam.

12 . The electrochemical cell of claim 10 , wherein the first seam is defined by overlapping portions of the first end of the continuous separator sheet and the second seam is defined by overlapping portions of the second end of the continuous separator sheet.

13 . The electrochemical cell of claim 10 , wherein the first seam is defined by abutted edges of the first end of the continuous separator sheet and the second seam is defined by abutted edges of the second end of the continuous separator sheet.

14 . The electrochemical cell of claim 10 , wherein the continuous separator sheet defines lateral slits perpendicular to a longitudinal axis of the continuous separator sheet, wherein the lateral slits separate the first end and the second end of the continuous separator sheet.

15 . The electrochemical cell of claim 14 , wherein the first end is longer than the second end of the continuous separator sheet.

16 . The electrochemical cell of claim 15 , wherein the length of each of the first end and the second end is greater than the height of the ring-shaped cathode.

17 . The electrochemical cell of claim 16 , wherein the length of the first end is longer than the combination of the height of the ring-shaped cathode and a diameter of the hollow interior of the ring-shaped cathode.

18 . The electrochemical cell of claim 8 , further comprising positioning a separator reinforcement layer adjacent the closed bottom end of the cylindrical separator.

19 . The electrochemical cell of claim 18 , wherein the separator reinforcement layer comprises one of a reinforcing cup or a reinforcing pad.

20 . The electrochemical cell of claim 8 , wherein the separator sheet comprises 3 mil separator paper.

Assignees

• Energizer Brands Llc

Inventors

• Kalisz David Walter
• Verikakis Maria G
• Bolyos Christopher S

Classifications

• H01M6/02 Primary

  Details (of electrodes H01M4/00; of non-active parts H01M50/00) · CPC title

• H01M2220/30

  Batteries in portable systems, e.g. mobile phone, laptop · CPC title

• H01M2/145

  Electricity · mapped topic

• H01M2/1686

  Electricity · mapped topic

• H01M2/022

  Electricity · mapped topic