JPS598276A - Battery - Google Patents

Abstract

PURPOSE:To increase the period maintaining a constant discharge current by increasing by 120-160% theoretical dischrge capacity of a negative electrode spreading in both directions to enlarge its surface area against effective theoretical discharge capacity of a positive electrode in a battery using a light metal such as lithium as a negative electrode. CONSTITUTION:When MnO2, CuO, or FeS2 is used in a positive electrode 18, effective theoretical discharge capacity is calculated based on theoretical discharge capacity in the dischrge reaction which Mn<4+> is discharged to Mn<3+>, Cu<2+> to Cu, or Fe<4+> to Fe. Increase of theoretical discharge capacity of a negative electrode 22 results in increase of utilization of a positive electrode 18 and prevention of decrease of effective reaction area of the negative electrode 22. Decrease of effective reaction area is substantially prevented when theoretical discharge capacity of the negative electrode 22 is increased by 120% or more against effective discharge capacity of the positive electrode 18. Even if theoretical discharge capacity of the negative electrode 22 is increased by 160% or more against effective discharge capacity, decrease of effective reaction area is prevented, but increase of more than 160% is not profitable.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to batteries, particularly those using a light metal such as lithium together with a non-aqueous electrolyte.

This type of battery has a high theoretical energy density by using a light metal such as lithium, potassium, botrium, calcium, magnesium, or aluminium-11 for the negative electrode, and therefore can be constructed as a particularly small battery with a high lightning capacity. suitable for. The battery of this scale is called a light metal battery because it uses a light metal such as lithium, or an aqueous electrolyte battery because it uses a non-aqueous electrolyte solution. Figure 1: An example of a non-aqueous electrolyte battery. According to the fi'I1 diagram, the battery is ゛1!
The photoelectric power station 3 is placed inside the heavy oil reservoir 16, which is formed in the shape of a hotan.
0 is stored in a sealed state. The battery cooler 16 consists of a stopper rod ff1lO, 'C' 41 pieces 12 and sealing gas shoes 1-14. Further, the power generation element 30 includes a positive electrode 18. whose main ingredient is a metal oxide such as manganese dioxide. It consists of a separator 20 impregnated with a non-aqueous electrolyte and a negative electrode 22 made of metal lithium. In the illustrated example, the negative electrode 22 is 1
1'I! Although it is exaggerated and shown thick to make it easier to solve, it is actually expanded to be thinner in the plane direction, expanding the surface area of the plane, and making it possible to conduct a higher current density. . .

Further, FIG. 2 shows an example of a 1U cylindrical non-aqueous electrolyte battery. As shown in the figure, the battery has a spirally wound structure in a cylindrical battery case 16 (a power generation element 30 is housed in a sealed state). The negative electrodes 22 are each formed into a band shape and have a state C in which they are layered with fIi (volume 1111,
It is stored in a sealed state in a battery dozen 1G containing a J1 water electrolyte 24. In this case, positive electrode 18 and negative electrode 4II
22 are positive electrode leads 1 to 26 and negative electrode leads F, respectively.
Negative terminal ff112△ and positive terminal 10△ via A28
In addition, an insulating plate 32 is interposed between the source t1[,, element 30, and the bottom surface of the negative electrode 12Δ. The positive electrode 18t) is expanded and is supported and shaped by a negative electrode current collecting member 34 which also serves as a core made of punched metal (perforated metal plate) or the like.
It is supported and shaped by a positive electrode current collecting member 35 which also serves as a core body.

As mentioned above, in this type of battery, by making the negative electrode 22 as thin as possible to increase the surface area! + The current density is set to 1!7. Therefore, in expanding the surface area by expanding the negative electrode 22 thinly in this way, J.
Theoretically, there is an opportunity to make effective use of the high energy density to create a compact battery with high discharge performance for the first time. By the way, the theoretical discharge capacity of the negative electrode of a conventional battery of this type (83L) is about 10 to 110% of the effective theoretical discharge sound tf4. If the positive electrode 18
What C1 pole 22 reacts ideally! I can do it Lf
, the theoretical discharge sound 10 of the negative electrode 22 stops [100%-(' with respect to the effective theoretical discharge sound tl'1 of i18). Attempts have been made to make the theoretical capacities of the positive and negative electrodes very different.
The effective theoretical discharge capacity of No. 18 is to be reduced by about 20%. This increases the utilization rate of the negative electrode 22.
In addition, since the negative electrode 22 is consumed first, the end of discharge becomes clearer. However, it depends on the uninventive people who have learned it. The zero pole in this type of battery has a discharge characteristic that allows the wear and tear to proceed uniformly as the discharge progresses, so that the end of the discharge can be clearly seen. It turns out that this is actually quite difficult, since the negative electrode 22, which has 4J in this second battery, is
j, J, Uni, C In order to obtain as high a current density as possible by 1q, it is necessary to expand the surface area by expanding the surface area by expanding the negative electrode 2 as thinly as possible.
When the power generating element 30 is constructed by placing the negative electrode 22 face-to-face with the positive electrode 18 via the separator 20, as shown in FIG. It was confirmed that as the discharge progressed, defects were formed partially, and as the discharge progressed further, the defects were expanded and consumed.

In other words, the thickness does not decrease uniformly as a whole as the discharge progresses, but each effective reaction area decreases as the discharge progresses.

For this reason, negative I! 1i, the theoretical IIi capacity standard of 22 is 1[
By reducing the deviation of pole 18, in reality, only the discharge characteristics shown in curve A in the graph of 4th M can be obtained. T!
i′? In reality, it was extremely difficult. The consumption of the negative electrode 22 is not uniform over the entire surface 111
The reason for this is the close contact with the iE electrode 18, the wetness of the negative electrode 22 itself, or the thickness of the lever lever 20, which is largely due to the difference in d3, but all of these variations can be suppressed. This is impossible in reality. It is certain that reducing the effective theoretical discharge capacity J of 1lE4118 from the immediate theoretical discharge capacity l of 22 to the effective theoretical discharge capacity J of 11E4118 will increase the utilization rate of 22 It may be effective for
The usage rate of ile 14!18 will definitely drop.

This (Z c, the high 1 energy density of this divine battery is
The electrochemical theory of the material of the negative electrode 22, 1Nel''
1゛- It depends a lot on the height of the density, so the negative electrode 2
Reducing the theoretical discharge capacity of 2 - C 11 and increasing the effective theoretical discharge capacity of 18 poles A) means increasing the capacity of the power generation element 30 - C and increasing the discharge sound ω. It's too close to 4r.

This is because the theoretical discharge sound fi per volume is even larger at the negative electrode in a battery of this scale.

On the other hand, the theoretical discharge capacity of negative i22 is increased to about 110% with respect to the effective theoretical discharge sound φ of one pole. Although it is possible to avoid the effect of increasing the rate, it is impossible to prevent the negative electrode 22 from decreasing its effective reaction area due to non-uniform reaction as the discharge progresses. As shown in the curve in the graph of Figure 4, the discharge characteristics of the discharge current do not appear in the light M [1], and the discharge current slowly decreases in the middle to late () of /J51 lightning. What about the IJ characteristics?

This invention was made in view of the above-mentioned conventional problems. The effective reaction area of the negative electrode can be increased without sacrificing the characteristic of large C discharge capacity! By holding the current until the end of the current, it is possible to secure a longer period than before for which a constant discharge current can be maintained, while at the same time making it possible to clearly distinguish the end of the current from the positive electrode. J
The object of the present invention is to provide a battery that can greatly increase the usable discharge capacity that can be actually used effectively, while comprehensively improving the utilization rate of the negative electrode and the negative electrode.

In order to achieve the above object (this invention), the negative electrode as described in 11. A battery d3 consisting of a photovoltaic cell d3 with an element oriented to the photoelectrode '1' which is oriented in the direction of 1F (the theoretical discharge capacity of the negative electrode is 120.
～・It is characterized by setting it to 160%.

As mentioned above, preferred embodiments of the present invention will be described based on the drawings. About the moon
The same reference numerals will be used for the same or corresponding parts in C.

The battery used in this defense example is shown in Figure 1, 13.
and are shown in Figure 2, respectively. The basic structure of JJ, Uni, and Zo is the same as the conventional one described above. However, that [1
The 1IIj theoretical discharge capacity C1 of the pole 22 is the effective I(1
1 argument 7 [(for one pair 120-, 160% ni'
J-,) 'C Iru. According to the knowledge of the present inventors, for example, a negative electrode (~22
In a battery using
In addition to this, it has been found that the decrease in the effective reaction area of the negative electrode 22, which has not been solved in the past, can be reliably prevented.

Furthermore, the reduction in the effective reaction area is due to the fact that the theoretical discharge capacity of the negative electrode 22 (i is 20% smaller than the effective theoretical discharge capacity of the positive electrode 18).
It was disgusting that the number of people suddenly appeared even though the number of people was expected to increase. Further, even if the theoretical discharge capacity of the negative electrode 22 is set to 160% or more of the effective M capacitance of the positive electrode 1, it is possible to reliably prevent a decrease in the effective reaction area in the vicinity; It was also confirmed that there was no profit from increasing the amount too much.

This invention has been made based on the above knowledge, and the effective discharge capacity on the iE electrode side is calculated as follows. 1, that is, the positive electrode 18 is Mnot, GuQ
If either of Fe32 or Fe32 is used as the main agent, M
114-1 is Mn31. CIJ2+ is CU, I”84+
is calculated based on the theoretical discharge capacity when it becomes "e".

Therefore, in a battery in which the theoretical discharge capacity of the negative electrode 22 is determined as described above, the utilization rate of the positive electrode 18 can be improved by increasing the discharge capacity. 11 (The effect of the reaction surface of 22 is 1.'J and the constant discharge current is maintained.) The overall utilization rate of the negative electrode 22 is increased, and the discharge capacity M is increased as a result. , the end of discharge clearly appears, and the end of discharge is just at the very end of the cycle.The best way to use the battery is to accurately determine when to replace the battery. 1. Furthermore, the conventional negative electrode 2 is often used, but the amount used is such that the theoretical molding volume of the negative electrode 22 is 11 ru. Since the effective discharge capacity of 18 is in the range of 4r to 120/16 (1%), the use of the negative electrode 22 in this J range is such that the 11 electrode 22 itself has a high energy density. Therefore, compared to the idle volume of the power generating element 30, it is almost negligible and is very small.
In fact, in order to increase the discharge capacity, the positive electrode's discharge capacity is 1 liter more than that of the 0 pole. b than before
The volume of the power generating element is small.

The battery according to this invention has one of the characteristics of a battery using a negative electrode such as lithium, which has a theoretically high energy density J mark.
It is possible to maintain the effective reaction area of the negative electrode until the final stage of discharge without causing any loss, thereby improving the overall utilization rate of the negative electrode and positive electrode, improving the discharge performance, and further discharging. Final state t] becomes clear and the battery can be used efficiently to the end.

[Brief explanation of the drawing]

FIG. 1 and FIG. 2 are sectional views each showing an example of the configuration of a battery according to the present invention. FIG. 3 is a graph showing the reduction in the effective reaction area of the negative electrode of the IJ in a conventional battery, and FIG. 4 is a graph comparing the discharge characteristic curves of the battery according to the present invention and the conventional battery. 10... ・・・ ・・・ i]i #season can 10
Δ...Positive terminal 12...Negative terminal 12△...0 pole can 14...110 To sword 1 to 1.・・・
...Battery Guno 18...1 "Pole 20...Leverator 22...F1 pole 24... ...Non-aqueous type Wf 8'j. 30......Generation Susume Seiko'1 Applicant Fuji Electrochemical Co., Ltd. Representative Bentoshi ~ Color Kano Shaft cylinder 1 Figure 2 Figure 3 Figure 4 Ginma-

Claims (1)

[Claims] A battery having a power generation element consisting of a negative electrode formed by spreading a light metal such as lithium thinly in a planar direction to increase its surface area, and a positive electrode facing the negative electrode through a separator containing a non-aqueous electrolyte. A battery characterized in that the theoretical discharge capacity of the negative electrode is 120 to 160% of the effective theoretical discharge capacity of the positive electrode.