Nonaqueous electrolyte secondary cell

• US 6,458,485 B2
• Filed: 03/29/2001
• Issued: 10/01/2002
• Est. Priority Date: 09/21/1998
• Status: Expired due to Fees

• Current Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Inventors: Yanagida, Katsunori, Yanai, Atsushi, Funahashi, Atsuhiro, Nohma, Toshiyuki, Maeda, Takeshi, Nishio, Koji, Yonezu, Ikuo, Ohkita, Kazunari, Chikano, Yoshito
• Primary Examiner(s): Maples, John S.
• Application Number:
  US09/819,643
• Publication Number:
  US 20010018147A1
• Time in Patent Office: 551 Days
• Field of Search: 429/94, 429/211, 429/245, 429/178, 429/324
• US Class Current: 429/211
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/4235 Safety or regulating additives or arrangements in electrodes, separators or electrolyte H01M10/4242 takes precedence
• CPC Class Codes: H01M 2200/106 PTC
• CPC Class Codes: H01M 4/02 Electrodes composed of, or comprising, active material
• CPC Class Codes: H01M 4/64 Carriers or collectors
• CPC Class Codes: H01M 50/538 Connection of several leads or tabs of wound or folded electrode stacks
• CPC Class Codes: H01M 6/10 with wound or folded electrodes
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A nonaqueous electrolyte secondary cell having a rolled-up electrode unit housed in a cell can and comprising a positive electrode and a negative electrode each formed by coating a surface of a striplike current collector with an electrode material. According to a first embodiment, the current collector of at least one of the positive electrode and the negative electrode comprises a plurality of current collector pieces 42 arranged along one direction and a PTC element 5 interconnecting each pair of adjacent current collector pieces 42. Alternatively with a second embodiment, at least one of the positive electrode and the negative electrode comprises a PTC element held between opposed faces of an uncoated portion of the current collector thereof and a base end portion of a current collector tab. The PTC element serves to prevent continuous occurrence of a current in excess of a predetermined value and realizes a high energy density.

Claims

1. A nonaqueous electrolyte secondary cell comprising an electrode unit housed in a cell can for delivering the electric power generated by the electrode unit from an electrode terminal assembly attached to the cell can, the electrode unit comprising a positive electrode and a negative electrode each provided by coating a surface of a striplike current collector with an electrode material to form coated portions and an uncoated portion not coated with the electrode material, a current collector tab having a base end portion connected to the uncoated portion and an outer end portion connected to the electrode terminal assembly, at least one of the positive electrode and the negative electrode being provided with an element having a positive temperature coefficient of resistance and held between opposed faces of the uncoated portion of the current collector thereof and the base end portion of the current collector tab.

2. A nonaqueous electrolyte secondary cell according to claim 1 wherein the element has a thickness in the range of 10 μ

m to 500 μ

m.