Battery and protecting element therefor

• US 5,939,217 A
• Filed: 10/15/1997
• Issued: 08/17/1999
• Est. Priority Date: 10/29/1996
• Status: Expired due to Term

• Current Assignee: Sony Chemicals Corp. (Dexerials Corporation)
• Original Assignee: Sony Chemicals Corp. (Dexerials Corporation)
• Inventors: Tamura, Hisaya, Iwasaki, Norikazu, Takeichi, Motohide
• Primary Examiner(s): Nuzzolillo, Maria
• Assistant Examiner(s): WILLS, MONIQUE M
• Application Number:
  US08/950,488
• Time in Patent Office: 671 Days
• Field of Search: 429/53, 429/56, 429/61, 429/62, 429/64, 429/82, 429/178, 429/57, 429/58, 429/7
• US Class Current: 429/7
• CPC Class Codes: H01H 2037/768 characterised by the composition of the fusible material
• CPC Class Codes: H01H 37/761 with a fusible element forming part of the switched circuit H01H37/767 takes precedence
• CPC Class Codes: H01M 2200/103 Fuse
• CPC Class Codes: H01M 2200/106 PTC
• CPC Class Codes: H01M 50/3425 in the form of rupturable membranes or weakened parts, e.g. pierced with the aid of a sharp member
• CPC Class Codes: H01M 50/581 in response to temperature
• CPC Class Codes: H01M 50/583 in response to current, e.g. fuses
• CPC Class Codes: H01M 6/10 with wound or folded electrodes

Abstract

A battery having a protecting element which has a simple structure and is easy to be miniaturized to permit installation within the battery cell without altering the structure and the production plan of the battery cell to a considerable extent and which has a function of melting down reliably upon detection of an abnormal state of the temperature or current of the battery. The protecting element 1 is formed from a base board 5 which is composed of an insulator layer 2 interposed between a first and a second conductor layer 3 and 4 and is provided with a through-hole 6 so as to bring about electrical conduction between the first and second conductor layers, wherein one of the conductor layers (3) is subdivided into a plurality of independent conductor layer patches (3a and 3b) separated by a vacant space 7 and the so-separated patches (3a and 3b) are bridged with a low-melting metal layer 8 to provide electrical conduction therebetween to build up a fuse unit 11 sealed by a protection member 10 and a safety valve 15 is formed in the through-hole 6 by covering the through-hole 6 with a lamellar closure member 13, wherein the protecting element 1 is installed in the battery cell integrally with the cathode terminal 16 via a PTC element.

Claims

1. A battery having a protecting element, which comprises

a cathode and an anode for effecting electrode reactions disposed in an electrode reaction part,

a cathode terminal connected to the cathode,

an anode terminal connected to the anode and

a protecting element inserted in the connecting current path from the cathode to the cathode terminal or in the connecting current path from the anode to the anode terminal,

said protecting element comprising

a base board composed of a first and a second conductor layer and an insulator layer interposed between said first and second conductor layers,

a through-hole formed in the base board and a conductive member contained therein to provide electrical conduction between the first and the second conductor layers,

at least one vacant space disposed in at least either one of said conductor layers in such a pattern as to leave a plurality of independent patches of conductor layer which are separated by the vacant space and

one or more layers of a low-melting metal so arranged as to bridge the separated conductor patches to provide electrical conduction therebetween.

2. A battery as claimed in claim 1, wherein the protecting element is inserted in the current path from the cathode to the cathode terminal.

3. A battery as claimed in claim 2, wherein the first conductor layer connects to the cathode terminal and the second conductor layer connects to the cathode.

4. A battery as claimed in claim 1, wherein the protecting element includes a lamellar closure member fixed to the base board so as to cover and close the through-hole.

5. A protecting element for battery, comprising

a base board composed of a first and a second conductor layer and an insulator layer interposed between said first and second conductor layers,

a through-hole formed in the base board and a conductive member contained therein to provide electrical conduction between the first and the second conductor layers,

at least one vacant space disposed in at least either one of said conductor layers in such a pattern as to leave a plurality of independent patches of conductor layer which are separated by the vacant space and

one or more layers of a low-melting metal so arranged as to bridge the separated conductor patches to provide electrical conduction therebetween.

6. A protecting element as claimed in claim 5, wherein it includes a lamellar closure member fixed to the base board so as to cover and close the through-hole.

7. A protecting element as claimed in claim 5, wherein the first conductor layer is made of copper and the second conductor layer is made of aluminum.

8. A protecting element as claimed in claim 5, wherein the low-melting metal layer is covered by flux.

9. A protecting element as claimed in claim 5, wherein the junction portions between the low-melting metal layer and the conductor patches are covered by a protection member.