Separator insert for electrochemical cells
First Claim
1. An electrochemical cell comprising:
- (a) an anode comprising an anode active material in contact with an anode current collector;
(b) a cathode comprising an electrode active material in contact with a cathode current collector;
(c) a separator provided between the anode and the cathode operatively associated with each other, the separator preventing internal electrical short circuit conditions;
(d) a separator insert provided to cover an edge and at least one side of at least one of the anode and the cathode, the separator insert extending along the at least one anode and cathode a distance less than one-half the length thereof to prevent the covered portion of the one current collector in contact with the at least one anode and cathode from tearing through the separator and the separator insert; and
(e) an electrolyte activating the operatively associated anode and the cathode.
8 Assignments
0 Petitions
Accused Products
Abstract
A separator insert used in addition to the main separator in an electrochemical cell, is described. A preferred material for the separator insert is a woven or nonwoven fluropolymeric material such as tetrafluoroethylene-ethylene copolymer (PETFE). This polymeric material is chemically inert to the components used in alkali metal cells, is corrosion resistant and does not decompose at normal battery temperatures. Preferably, the separator insert covers at least each side of the cathode means in a spirally wound electrode stack and extends less than one-half the total length thereof. This provides additional protection against internal short circuit conditions due to tearing or puncture of the traditional separator cause by exposed electrode screens.
64 Citations
22 Claims
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1. An electrochemical cell comprising:
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(a) an anode comprising an anode active material in contact with an anode current collector; (b) a cathode comprising an electrode active material in contact with a cathode current collector; (c) a separator provided between the anode and the cathode operatively associated with each other, the separator preventing internal electrical short circuit conditions; (d) a separator insert provided to cover an edge and at least one side of at least one of the anode and the cathode, the separator insert extending along the at least one anode and cathode a distance less than one-half the length thereof to prevent the covered portion of the one current collector in contact with the at least one anode and cathode from tearing through the separator and the separator insert; and (e) an electrolyte activating the operatively associated anode and the cathode. - View Dependent Claims (3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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2. The electrochemical cell wherein the anode and the cathode are operatively associated with each other in a spirally wound configuration and the separator insert covers a leading edge of at least one anode and cathode beginning at a center position of the spirally wound electrode configuration.
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13. In an electrochemical cell comprising:
- an anode having an anode active material in contact with an anode current collector;
a cathode comprising an electrode active material in contact with a cathode current collector;
a separator provided between the anode and the cathode operatively associated with each other in a spirally wound configuration, the separator preventing internal electrical short circuit conditions; and
an electrolyte activating the operatively associated anode and the cathode, the improvement comprising;a separator insert covering a leading edge and at least one side of at least one of the anode and the cathode beginning at a center position of the spirally wound electrode configuration and extending along at least one anode and cathode a distance less than one-half the length thereof to prevent the covered portion of the one current collector in contact with the at least one anode and cathode from tearing through the separator and the separator insert, the separator insert in that manner providing additional protection against internal electrical short circuit conditions. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20, 21, 22)
- an anode having an anode active material in contact with an anode current collector;
Specification