JPH0850901A - Battery - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide an electrochemical cell with a discharge life indicator that can extend the voltage duration in the vicinity of discharge life (EOS) [Structure] Active metal negative electrode such as lithium, organic solvent electrolyte and A battery employing a positive electrode made of manganese dioxide and / or carbon monofluoride. Second cathode material βA
gxV2O5, δAgxV2Os, Ag2V4O11,
BiF3 and TiS2 are added to a selected primary cathode material (MnO2 and / or CFX) in a certain ratio to realize a lower voltage decreasing tendency than that of the original primary cathode materials MnO2 and CFX alone, and sustaining voltage near EOS. Extend the voltage duration capacity near time, ie EOS.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a non-aqueous electrolysis used for high rate discharge by employing an active metal negative electrode such as lithium, an organic solvent electrolyte and a positive electrode composed of manganese dioxide and / or monofluorocarbon. Regarding the battery using the liquid, the positive electrode is a discharge life (EOS) indicator, vanadium oxide (V6O13 + y), silver vanadate βAg
xV2O5, δAgxV2O5, Ag2V4O11, bismuth fluoride (BiF3), titanium sulfide (TiS)
2) Containing a predetermined amount of a substance selected from the group consisting of.

[0002]

2. Description of the Related Art General Li / MnO2 or Li / CF
X type battery (electrochemical battery, cell, battery)
Are known and are disclosed in US Pat. Nos. 4,327,166 and 4,259,415. This type of battery uses a negative electrode of lithium, potassium, sodium, calcium, magnesium, aluminum or an alloy thereof (hereinafter referred to as an active metal). Further, such a battery uses a positive electrode of manganese dioxide (MnO2), carbon monofluoride (CFX) or a mixture thereof.
Further, such a battery uses an electrolytic solution of an ionized solute dissolved in an organic solvent. For example, one battery uses 1 mole of LiClO4, 50/50 (vol%) propylene carbonate / diglyme or glyme as electrolyte and has a water content of at most about 50 ppm (in some circumstances at most 100 ppm is acceptable). May be).

These Li / MnO2 or Li / CFX
Batteries of this type are often used in medical devices, are sufficient for use with light discharges, and show a gradually decreasing voltage curve. By the way, the latest generation medical devices have severe power requirements such as high rate discharge conditions. When used under high rate discharge conditions, the gradual discharge tendency is lost, and the service life of the battery is the discharge life (hereinafter simply referred to as EOS).
Ends abruptly with a sharp voltage drop at. This is insufficient as the performance of the battery for the medical device, and means for reporting the battery exhaustion or the start of EOS, that is, the remaining battery life monitoring is required.

For this reason, it is generally known in the battery art to use synthetic electrodes of different potentials to signal battery exhaustion. For example, regarding synthetic positive electrodes, Mr. Doty and F.
U.S. Pat. No. 3,757,793 to Ester
No. 4,619,874 to Hayes and Skarstad, and US Pat. No. 4,259,415 to Tamura et al. Such a positive electrode is referred to as a "synthetic positive electrode" and has the function of indicating the onset of battery energy consumption in the form of a reduced voltage signal from the battery.

[0005]

However, such a discharge life indicator function of the conventional battery is not suitable for severe power conditions such as the above-mentioned voltage characteristics having a high rate discharge condition. There was a desire for improvement in.

The present invention has been made in view of the above problems of the prior art, and it is an object of the present invention to provide an electrochemical cell with a discharge life indicator capable of extending the voltage duration in the vicinity of EOS with respect to the known and the above-mentioned types of cells.

[0007]

In order to achieve the above object, a battery according to the present invention has (a) an active metal negative electrode, (b) a liquid organic solvent electrolyte, and (c) V6O13 + y, βAg.
xV2O5, δAg xV2O5, Ag2V4O11, B
First selected from the group consisting of iF3 and TiS2
It is configured to have a synthetic positive electrode that encloses a substance.

The battery according to the present invention may be configured such that the active metal negative electrode is lithium.

In the battery according to the present invention, the positive electrode mixture is CFx
And V6O13 + y.

The battery according to the present invention may further include a conductivity enhancer and a binder in the positive electrode mixture.

The battery according to the present invention may be configured such that the conductivity enhancer is conductive carbon.

The battery according to the present invention may be configured such that the chemical capacity ratio of the first component to the second component of the positive electrode mixture is about 2: 1.

The battery according to the present invention may be configured such that the chemical capacity ratio of the first component to the second component of the positive electrode mixture is about 4: 1.

In order to achieve the above object, the battery according to the present invention comprises (a) a lithium metal negative electrode, (b) a liquid organic solvent electrolyte containing gamma-butyrolactone and LiBF4,
Then, (c) a positive electrode material containing V6O13 + y.

Further, in order to achieve the above object, the battery according to the present invention is composed of (a) an active metal negative electrode, (b) a liquid organic solvent electrolytic solution, and (c) a positive electrode material containing CFx and V6O13 + y. It is a thing.

The battery according to the present invention may have a structure in which the negative electrode is lithium.

The battery according to the present invention comprises CFx and V6O13 +
The chemical capacity ratio of y may be about 2: 1.

Thus, the present invention relates to a battery of the type known and described above, in which the second cathode material βAgxV2O5, δAg.
xV2Os, Ag2V4O11, BiF3, TiS2 are added in a ratio to the selected primary cathode material (MnO2 and / or CFX) to extend the voltage duration near EOS, ie the voltage duration capacity near EOS. These additions are based on the original primary cathode materials MnO2, C
It realizes a lower voltage reduction trend than that of FX alone. Any of the additives, in order to allow the desired binding properties,
That is, in order to provide a dischargeable capacity portion within a specific voltage interval range, the primary cathode material may be mixed in any mixing ratio.

In one preferred form of the invention, the battery comprises a lithium negative electrode, a MnO2 positive electrode and a small amount of compounds (Ag2V4O11, δAgxV2O5 as the active ingredient,
βAgxV2O5 or V6O13 + y, conductive component consisting of carbon or graphite, and binder component such as PTFE)
Consists of The latter two components are used to increase the performance of the battery. Carbon or graphite increases the conductivity and discharge rate of the positive electrode. The binder holds the positive electrode. The battery contains an electrolyte such as an electrolyte having 1M 50/50 diglyme / propylene carbonate in LiClO4 or other organic electrolyte capable of carrying lithium ions.

The cell is preferably hermetically sealed by means of a suitable current collector embedded in the electrode, for example a microporous polyethylene or polypropylene layered nonwoven polypropylene or polyethylene, and preferably a weld. It consists of a suitable metal case, preferably stainless steel. A known corrosion-resistant glass through-connector is used for electrical contact in the sealed portion of the battery.

Another preferred form of the present invention is that a carbon monofluoride (CFX) cathode is used with any of the above mentioned cathode additives having an additive to CFX ratio of 2: 1 in a stoichiometric capacity ratio. Similar to that described above. Other ratios of additive to CFX, such as stoichiometric ratio, may be, for example, 3: 1, 4: 1, 1: 1.

[0022]

Embodiments of the present invention will be described below with reference to the drawings.

The battery of this example is a lithium negative electrode, 1 mol of LiClO 4, 50/50 (vol%) propylene carbonate / diglyme or an electrolyte solution containing glyme, and the following A to E containing 15 to 44 ppm of water. It has such a synthetic positive electrode. A. V6O13 + y + MnO2 B.I. V6O13 + y + CFx C.I. Ag2V4O11 + CFx D.I. Ag2V4O11 + MnO2 E.I. BiF3 + CFx All positive electrodes of A-E above contain 5 wt% PTFE, 3 wt% carbon black and 3 wt% graphite, and their pulsed discharge curves are shown in FIGS.

A comparative discharge curve of only the primary cathode material is shown in FIG.
And 7 are shown. 1 mol of Li in gamma-butyrolactone
Similar results were obtained when similar batteries were made and tested using the electrolyte containing BF4.

The preferred synthetic positive electrode composition has the following stoichiometric ratio: 2: 1 CFx: V2O5 2: 1 CFx: V6O13 + y 4: 1 CFx: V2O5 4: 1 CFx: V6O13 + y (The above ratios are expressed in terms of relative stoichiometric volumes defined by the components.)

Background information on CFx can be found in T.W., entitled "Fluorinated Graphite and Fluorocarbon Compounds." Nakajima
Mr. and N. It is described in the CRC Press paper (1991) by Watanabe.

An additional feature of the present invention is that V6Ol3 + y as the second positive electrode material is LiB in which the electrolyte is 1 molar.
In the case of gamma-butyrolactone containing F4, it is to suppress corrosion in sealed Li / CFx cells compared to the other examples described above. This represents a particular preferred embodiment of the invention.

In another particular preferred embodiment of the invention, C
Using a positive electrode material with the combination of Fx and V6Ol3 + y, this example produces a higher pulse voltage than either CFx or V6Ol3 + y, as clearly shown by comparison with FIGS. 2 and 7, 8. It is possible.

[0029]

According to the invention, a second positive electrode material βAgxV2O5, δ is provided for a battery of the known and previously described type.
AgxV2O5, Ag2V4O11, BiF3, TiS
The addition of 2 in a ratio to the selected primary cathode material (MnO 2 and / or CFX) extends the voltage duration near EOS, ie the voltage duration capacity near EOS. These additions are based on the original primary cathode material MnO.
2. Realize a lower voltage decrease tendency than that of CFX alone.

[Brief description of drawings]

FIG. 1 is a first graph showing EOS characteristics of a battery according to the present invention.

FIG. 2 is a second graph showing the EOS characteristics of the battery according to the present invention.

FIG. 3 is a third graph showing the EOS characteristics of the battery according to the present invention.

FIG. 4 is a fourth graph showing the EOS characteristics of the battery according to the present invention.

FIG. 5 is a fifth graph showing EOS characteristics of the battery according to the present invention.

FIG. 6 is a graph showing a discharge curve of only a primary cathode material for comparison.

FIG. 7 is another graph showing a discharge curve of only the primary cathode material for comparison.

FIG. 8 is yet another graph showing a discharge curve of only the primary cathode material for comparison.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor John W. Cretts Meyer 55423 Litchfield, Minnesota, USA Oliver Avenue South 7604 (72) Inventor Anne M. Crespi United States Minnesota 55417 Minneapolis, Twelves Avenue South 7604 (72) Inventor William G. Howard United States Minnesota 55113 Roseville, North Fisk Street 2550 (72) Inventor Paul M. Scarstad United States Minnesota 55447 Primos, Garland Lane 2415

Claims (11)

[Claims] 1. A battery comprising the following requirements. (A) Active metal negative electrode, (b) liquid organic solvent electrolyte, and (c) V6O13 + y, βAgxV2O5, δAgxV
A synthetic positive electrode encapsulating a first substance selected from the group consisting of 2O5, Ag2V4O11, BiF3, TiS2. 2. The battery of claim 1, wherein the active metal negative electrode is lithium. 3. The positive electrode mixture is CFx and V6Ol3 + y.
The battery according to claim 1 or 2, comprising: 4. The battery according to claim 1, further comprising a conductivity enhancer and a binder in the positive electrode mixture. 5. The battery according to claim 4, wherein the conductivity enhancer is conductive carbon. 6. The battery according to claim 1, wherein the chemical capacity ratio of the first component to the second component of the positive electrode mixture is about 2: 1. 7. The battery according to claim 1, wherein the chemical capacity ratio of the first component to the second component of the positive electrode mixture is about 4: 1. 8. A battery having the following requirements. (A) a lithium metal negative electrode, (b) a liquid organic solvent electrolyte containing gamma-butyrolactone and LiBF4, and (c) a positive electrode material containing V6O13 + y. 9. A battery comprising the following requirements. A positive electrode material containing (a) an active metal negative electrode, (b) a liquid organic solvent electrolyte, and (c) CFx and V6O13 + y. 10. The battery according to claim 9, wherein the negative electrode is lithium. 11. The battery according to claim 9, wherein the chemical capacity ratio of CFx to V6O13 + y is about 2: 1.