EP0251198A2
Expired / Lapsed
EP
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Apparatus for diagnosing abnormal state of sodium (Na) - sulfur (S) cell
Assignee: Hitachi Ltd
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Filing: 1987-06-25
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Granted: —
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Expires: 2007-06-25
Abstract
Abstract Disclosed is a method and apparatus which can detect progress of degradation of a sodium-sulfur cell (9) and predict possibility of final breakdown of the cell (9) in a very near future before such a final breakdown of the cell (9) actually occurs. The method and apparatus for diagnosing the presence or absence of an abnormal state in the sodium-sulfur cell (9), containing a porous electrical conductive material impregnated with molten sulfur or sodium polysulfide as its positive electrode reactant and containing sodium as its negative electrode reactant, comprises observing the operating voltage of the cell (9) during char ging and discharging so as to detect occurrence of a minute ripple in the operating voltage, and, when the amplitude of the ripple and the frequency of occurrence of the ripple increases as a result of repeated cycles of charging and discharging, deciding that degradation of the cell (9) has progressed to an extent that final breakdown of the cell (9) will occur in a very near future.
Inventors
- 👤 Yasumasa Ishida
- 👤 Hiroyuki Kawamoto
- 👤 Motoi Nobakaneichi Ichijo 301 Wada
- 👤 Hisamitu Hatoh
- 👤 Yoshiteru Miyatake
- 👤 Sadao Mori
- 👤 Eiji Takahashi
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 14:13
CPC Classifications
H; H01; H01M; H01M10/00; H01M10/42; H01M10/48; G; G01; G01R; G01R31/00; G01R31/36; G01R31/378; Y; Y02; Y02E; Y02E60/00; Y02E60/10
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
142 words
A method for diagnosing the presence or absence of an abnormal state in a sodium-sulfur (Na/S) cell (9) containing at least one of a porous electrical conductive material impregnated with molten sulfur and a porous electrical conductive material impregnated with molten sulfur or sodium polysulfide as its positive electrode reactant (8) and containing sodium as its negative electrode reactant (7), said method comprising observing the operating voltage of said sodium-sulfur cell (9) during charging and discharging so as to detect occurence of a minute ripple in the operating voltage, and, when the amplitude of said ripple and the frequency of occurrence of said ripple increases as a result of repeated cycles of charging and discharging, deciding that degradation of said sodium-sulfur cell (9) has progressed to an extent that final breakdown of said cell (9) will occur in a very near future.
Claim 2
Independent Claim
142 words
A method for diagnosing the presence or absence of an abnormal state in a sodium-sulfur (Na/S) cell (9) containing at least one of a porous electrical conductive material impregnated with molten sulfur and a porous electrical conductive material impregnated with molten sulfur or sodium polysulfide as its positive electrode reactant (8) and containing sodium as its negative electrode reactant (7), said method comprising observing the operating voltage of said sodium-sulfur cell (9) during charging and discharging so as to detect occurence of a minute ripple in the operating voltage, and, when the amplitude of said ripple and the frequency of occurrence of said ripple increases as a result of repeated cycles of charging and discharging, deciding that degradation of said sodium-sulfur cell (9) has progressed to an extent that final breakdown of said cell (9) will occur in a very near future.
Claim 3
Independent Claim
196 words
An apparatus for diagnosing the presence or absence of an abnormal state in a sodium-sulfur [Na/S) cell (9) containing at least one of a porous electrical conductive material impregnated with molten sulfur and a porous electrical conductive material impregnated with sodium polysulfide as its positive electrode reactant (8) and containing sodium as its negative electrode reactant (7), said apparatus comprising: a plurality of modules (26), each said module (26) being constituted by connecting a plurality of submodules (22) in series with each other, each said submodule (22) being constituted by connecting a plurality of said sodium-sulfur celles (9) in parallel with each other; a volt-meter (31) connected across each of said modules (26); a pulse detector (32) connected to said volt-meters (31) connected to said modules (26) respectively, for detecting a voltage ripple having a level exceeding a predetermined pulse peak value from an output of each of said voltmeters (31); an alarm generator (33) connected to said pulse detector (32) for generating an alarm when said ripple is detected; and a switch (34) connected to said pulse detector (32) and opened to stop charging and discharging said sodium-sulfur cells (9) when said ripple is detected.
Claim 4
Independent Claim
196 words
An apparatus for diagnosing the presence or absence of an abnormal state in a sodium-sulfur [Na/S) cell (9) containing at least one of a porous electrical conductive material impregnated with molten sulfur and a porous electrical conductive material impregnated with sodium polysulfide as its positive electrode reactant (8) and containing sodium as its negative electrode reactant (7), said apparatus comprising: a plurality of modules (26), each said module (26) being constituted by connecting a plurality of submodules (22) in series with each other, each said submodule (22) being constituted by connecting a plurality of said sodium-sulfur celles (9) in parallel with each other; a volt-meter (31) connected across each of said modules (26); a pulse detector (32) connected to said volt-meters (31) connected to said modules (26) respectively, for detecting a voltage ripple having a level exceeding a predetermined pulse peak value from an output of each of said voltmeters (31); an alarm generator (33) connected to said pulse detector (32) for generating an alarm when said ripple is detected; and a switch (34) connected to said pulse detector (32) and opened to stop charging and discharging said sodium-sulfur cells (9) when said ripple is detected.
Claim 5
Dependent Claim
22 words
An apparatus according to Claim 2, wherein said switch (34) is automatically opened to stop charging and discharging said sodium-sulfur cells (9).
References Cited (Backward Citations)
No citation records indexed.
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