JP2007042447A - Lithium/iron disulphide primary cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lithium/iron sulphide primary cell capable of reducing discharge characteristics, suppressing boost of open-circuit voltage at the time of preservation and having high quality. <P>SOLUTION: The lithium/iron sulphide primary cell is equipped with a cathode 2 having iron sulphide (FeS<SB>2</SB>) as a cathode active material, an anode 3 having lithium as an anode active material and electrolyte solution. Chain imide salt (LiN(C<SB>n</SB>F<SB>2n+1</SB>SO<SB>2</SB>)(C<SB>m</SB>F<SB>2m+1</SB>SO<SB>2</SB>)) is contained in the electrolyte solution. With this, drop of discharge characteristics is reduced, and boost of an open-circuit voltage can be suppressed at the time of preservation. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a lithium / iron disulfide primary battery including a positive electrode using iron disulfide as a positive electrode active material, a negative electrode using lithium as a negative electrode active material, and an electrolyte solution of an organic solvent.

  Currently available 1.5V class primary batteries include manganese batteries, alkaline manganese batteries, silver oxide batteries, air batteries, nickel / zinc batteries, and lithium / organic solvents that use organic solvents as electrolytes. There are iron disulfide primary batteries.

  The lithium / iron disulfide primary battery is composed of positive and negative electrode materials that have a very high theoretical capacity of about 894 mAh / g for the positive electrode active material iron disulfide and about 3863 mAh / g for the negative electrode active material lithium. The battery is extremely excellent in terms of battery characteristics such as high capacity and light weight, load characteristics, and low temperature characteristics.

  Furthermore, the lithium / iron disulfide primary battery has an initial open circuit voltage (OCV) of 1.7 to 1.8 V, an average discharge voltage of 1.3 to 1.6 V, and other 1.5 V class primarys. The practical value is also high in terms of compatibility with batteries, for example, manganese batteries, alkaline manganese batteries, silver oxide batteries, air batteries, and nickel / zinc batteries using an aqueous solution as an electrolyte.

  However, this battery system has a problem that the open circuit voltage rises to a potential higher than the practical voltage immediately after manufacture. Therefore, a method of reducing the open circuit voltage to a practical voltage by performing preliminary discharge after manufacture is taken, but the open circuit voltage rises again during long-term storage, and in some cases exceeds 2 V. have.

  When a lithium / iron disulfide primary battery in which the open circuit voltage is increased is used in a device, the protection circuit on the device side is activated, so that the power is not turned on and the device cannot be used. That is, the problem that compatibility with other 1.5V class primary batteries is lost arises.

  One possible cause of the increase in the open circuit voltage is the influence of oxygen adsorbed on the conductive agent. In order to suppress this influence, for example, the following Patent Document 1 describes a method for reducing and removing active species in a conductive agent by using an insaxol derivative added in an electrolytic solution and a reducing agent added in a positive electrode. .

JP 59-181464 A

  Another cause of the increase in the open circuit voltage is considered to be the influence of moisture ingress from outside and the reaction between the battery constituent components accompanying it. In order to suppress this influence, for example, Patent Document 2 described below describes a method of preferentially reacting ingress water with a phenol or hydroquinone derivative added to an electrolytic solution.

JP-A-8-153521

In the method described in Patent Document 1, an isoxazole derivative can react with an active species that contributes to an increase in the open circuit voltage and removes it, thereby suppressing an increase in the open circuit voltage. On the other hand, in this invention, an imide salt is used as the electrolyte salt, thereby suppressing an increase in open circuit voltage during long-term storage. Although the imide salt contained as an electrolyte exists as an N-containing anion in the electrolyte, the anion species forms a stable organic film on the positive electrode active material FeS ₂ in addition to reacting with the adsorption active species. Thus, it is considered that the rise in open circuit voltage is suppressed.

  In addition, in the method using an additive in the methods described in Patent Documents 1 and 2, there is a concern about a decrease in discharge characteristics. On the other hand, in the present invention, unlike the use of additives in the methods described in Patent Documents 1 and 2, adding as a salt is considered to lead to an increase in ionic conductivity, thereby impairing discharge characteristics. Therefore, it is considered that the open circuit voltage rise can be suppressed.

  Accordingly, an object of the present invention is to provide a high-quality lithium / iron disulfide primary battery in which the deterioration of discharge characteristics is small and an increase in open circuit voltage during storage can be suppressed.

（式中Ｒ１はＣ_nＦ_2n+1を表す、式中Ｒ２はＣ_mＦ_2m+1を表す） In order to solve the above-described problems, the present invention provides:
A positive electrode using iron disulfide as a positive electrode active material;
A negative electrode using lithium as a negative electrode active material;
A lithium / iron disulfide primary battery comprising an electrolyte solution,
The electrolytic solution is a lithium / iron disulfide primary battery characterized by containing a chain imide salt represented by the following chemical formula.

(Wherein R1 represents C _n F _{2n + 1} and R2 represents C _m F _{2m + 1} )

  According to the present invention, there is little deterioration in discharge characteristics, and an increase in open circuit voltage during storage can be suppressed.

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

  FIG. 1 shows a lithium / iron disulfide primary battery according to an embodiment of the present invention. The battery shown in FIG. 1 is a so-called cylindrical type, and has a spiral electrode body inside a substantially hollow cylindrical battery can 1. The spiral electrode body is formed by winding a strip-shaped positive electrode 2 having a positive electrode active material and a strip-shaped negative electrode 3 having a negative electrode active material through a separator 4 having ion permeability many times.

  The battery can 1 is made of, for example, iron plated with nickel, and has one end closed and the other end open. Inside the battery can 1, a pair of insulating plates 5 and 6 are arranged perpendicular to the peripheral surface so as to sandwich the spiral electrode body.

  At the open end of the battery can 1, a battery lid 7, a safety valve 8 and a heat sensitive resistance element (Positive Temperature Coefficient; PTC element) 9 provided inside the battery lid 7 are provided via a sealing gasket 10. It is attached by caulking and the inside of the battery can 1 is sealed.

  The battery lid 7 is made of, for example, the same material as the battery can 1. The safety valve 8 is electrically connected to the battery lid 7 via the heat sensitive resistance element 9, and when the internal pressure of the battery becomes a certain level or more due to internal short circuit or external heating, the safety valve 8 and the spiral lid A so-called current interrupting mechanism for disconnecting the electrical connection with the electrode body is provided.

  When the temperature rises, the heat-sensitive resistance element 9 limits the current by increasing the resistance value and prevents abnormal heat generation due to a large current, and is made of, for example, barium titanate semiconductor ceramics. The sealing gasket 10 is made of, for example, an insulating material, and the surface is coated with, for example, asphalt.

  A positive electrode lead 11 made of aluminum or the like is connected to the positive electrode 2 of the spiral electrode body, and a negative electrode lead 12 made of nickel or the like is connected to the negative electrode 3. The positive electrode lead 11 is electrically connected to the battery lid 7 by being welded to the safety valve 8. The negative electrode lead 12 is welded and electrically connected to the battery can 1.

  Further, the separator 4 between the positive electrode 2 and the negative electrode 3 is impregnated with, for example, a nonaqueous electrolyte as a nonaqueous electrolyte. The separator 4 has a function of preventing physical contact between the positive electrode 2 and the negative electrode 3 by being disposed between the positive electrode 2 and the negative electrode 3. Further, the separator 4 absorbs the non-aqueous electrolyte so as to hold the non-aqueous electrolyte in the holes and allow lithium ions to pass during discharge.

[Positive electrode 2]
The positive electrode 2 is composed of a positive electrode current collector having a strip shape and a positive electrode mixture layer formed on both surfaces of the positive electrode current collector. The positive electrode current collector is a metal foil such as an aluminum (Al) foil, a nickel (Ni) foil, a stainless steel (SUS) foil, or the like.

The positive electrode mixture layer includes, for example, iron disulfide (FeS ₂ ) that is a positive electrode active material, a conductive agent, and a binder. As the positive electrode active material, iron disulfide, which is obtained by pulverizing pyrite that exists mainly in nature, is used, but chemical synthesis, for example, ferrous chloride (FeCl ₂ ) is converted to hydrogen sulfide (H ₂ S). Iron disulfide obtained by firing inside can also be used.

  The conductive agent is not particularly limited as long as an appropriate amount can be mixed with the positive electrode active material to impart conductivity, and for example, carbon powder such as graphite and carbon black can be used. As the binder, a known binder can be used. For example, a fluorine resin such as polyvinyl fluoride (PVF), polyvinylidene fluoride (PVDF), polytetrafluoroethylene, or the like can be used.

[Negative electrode 3]
The negative electrode 3 is made of a metal foil having a strip shape. Examples of the metal foil material that is also the negative electrode active material include lithium metal or lithium alloy obtained by adding an alloy element such as aluminum to lithium.

[Electrolyte]
As the electrolytic solution, an electrolytic solution in which an electrolyte is dissolved in an organic solvent is used. Examples of the organic solvent include propylene carbonate, ethylene carbonate, 1,2-dimethoxyethane, γ-butyrolactone, tetrahydrofuran, 2-methyltetrahydrofuran, 1,3-dioxolane, sulfolane, acetonitrile, dimethyl carbonate, dipropyl carbonate, and the like. These may be used alone or in combination of two or more.

As the electrolyte, a chain imide salt represented by the following chemical formula can be used alone. Furthermore, as the electrolyte, a mixed salt obtained by mixing a chain imide salt represented by the following chemical formula and another lithium salt can be used. Specifically, as the electrolyte, for example, those in which R1 and R2 are any of CF ₃ , C ₂ F ₅ , C ₃ F ₇ , and C ₄ F _{9 in} the following chemical formula can be used. In addition, since chemical formula 1 and chemical formula 2 are the same chemical formula, in the following description, they are simply described as chemical formula 1.

（式中Ｒ１はＣ_nＦ_2n+1を表す、式中Ｒ２はＣ_mＦ_2m+1を表す）

(Wherein R1 represents C _n F _{2n + 1} and R2 represents C _m F _{2m + 1} )

Examples of other lithium salts include lithium perchlorate (LiClO ₄ ), lithium hexafluorophosphate (LiPF ₆ ), lithium tetrafluoroborate (LiBF ₄ ), and lithium trifluoromethanesulfonate (LiCF ₃ SO _3). ), Lithium iodide (LiI), or the like can be used.

  In one embodiment, by containing the chain imide salt shown in Chemical Formula 1 as an electrolyte in the electrolytic solution, there is little decrease in discharge characteristics and an increase in open circuit voltage can be suppressed. That is, the chain imide salt shown in Chemical Formula 1 contained as an electrolyte exists as an N-containing anion in the electrolyte, and this N-containing anion forms a stable organic film on iron disulfide that is a positive electrode active material. It is considered that the increase in open circuit voltage can be suppressed by reacting with the active species. Furthermore, adding as a salt may lead to an increase in ionic conductivity, and it is considered that an increase in open circuit voltage can be suppressed without impairing discharge characteristics.

  When the chain imide salt represented by Chemical Formula 1 exceeds 1.5 mol / kg in the electrolytic solution, the effect of suppressing an increase in open circuit voltage is saturated. Therefore, the chain imide salt shown in Chemical formula 1 is in the range of 0.1 mol / kg to 1.5 mol / kg electrolyte from the point of obtaining the effect of suppressing the increase in open circuit voltage according to the amount of addition. It is preferably included.

[Separator]
As the separator, for example, a polyolefin-based microporous film such as polypropylene or polyethylene can be used.

  Next, a method for manufacturing a lithium / iron disulfide primary battery according to an embodiment of the present invention will be described.

  First, for example, a positive electrode active material, a binder, and a conductive agent are mixed to prepare a positive electrode mixture, and this positive electrode mixture is dispersed in a solvent such as N-methyl-2-pyrrolidone (NMP) to form a paste A positive electrode mixture slurry is obtained. The positive electrode mixture slurry is applied onto a positive electrode current collector and dried, and then compression molded by a roller press or the like to form a positive electrode mixture layer. Thereby, the positive electrode 2 is produced.

  Next, the strip-shaped positive electrode 2 obtained as described above, the negative electrode 3 having the strip shape, and the separator 3 having the strip shape are, for example, in the order of the positive electrode 2, the separator 4, the negative electrode 3, and the separator 4. Laminated and wound many times in the longitudinal direction to produce a spiral electrode body.

  Next, the spiral electrode body is accommodated in the battery can 1 in which the insulating plate 5 is inserted in advance at the bottom and nickel plating is applied in advance on the inside. Then, the insulating plate 6 is disposed on the upper surface of the spiral electrode body. Thereafter, in order to collect current of the negative electrode 3, one end of the negative electrode lead 12 made of, for example, nickel is attached to the negative electrode 3 and the other end is welded to the battery can 1.

  As a result, the battery can 1 is electrically connected to the negative electrode 3 and becomes an external negative electrode. In order to collect the positive electrode 2, one end of the positive electrode lead 11 made of, for example, aluminum is attached to the positive electrode 2, and the other end is electrically connected to the battery lid 7 via the safety valve 8. As a result, the battery lid 7 is electrically connected to the positive electrode 2 and becomes an external positive electrode.

  Then, an electrolyte prepared by dissolving the chain imide salt shown in Chemical Formula 1 as an electrolyte in an organic solvent alone or mixed with another lithium salt was injected into the battery can 1, and then asphalt was applied. The battery can 1 is caulked through the sealing gasket 10. Thereby, a cylindrical lithium / iron disulfide primary battery with the battery lid 7 fixed thereto is manufactured.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples. However, the present invention is not limited to these examples.

<Example 1>
First, 95% by weight of iron disulfide as a positive electrode active material, 1.0% by weight of carbon powder as a conductive agent, and 4% by weight of polyvinylidene fluoride as a binder are mixed, and N-methyl as a solvent is mixed. A positive electrode mixture slurry was obtained by sufficiently dispersing in 2-pyrrolidone.

  Next, the positive electrode mixture slurry was applied to both sides of the positive electrode current collector, dried at a temperature of 120 ° C. for 2 hours to volatilize N-methyl-2-pyrrolidone, and then compression-molded at a constant pressure to form a belt-like positive electrode 2 was produced. As the positive electrode current collector, a band-shaped aluminum foil having a thickness of 20 μm was used.

  Next, the belt-like positive electrode 2 produced as described above and the lithium metal negative electrode 3 having a thickness of 150 μm are laminated in the order of the positive electrode 2, the separator 4, the negative electrode 3, and the separator 4, and then wound many times. A spiral electrode body having an outer diameter of 9 mm was produced.

  The spiral electrode body obtained as described above was stored in a nickel-plated iron battery can 1. The insulating plate 5 and the insulating plate 6 are arranged on the upper and lower surfaces of the spiral electrode body, the aluminum positive electrode lead 11 is led out from the positive electrode current collector, and the nickel negative electrode lead 12 is connected to the negative electrode. Derived from the current collector and welded to the battery can 1.

Next, with respect to a mixed solvent of 1,3-dioxirane (DOL) and 1,2-dimethoxyethane (DME) in a volume ratio of 2: 1, 1.0 mol / kg of lithium iodide and R1 An electrolytic solution prepared by adding and dissolving 0.05 mol / kg of a chain imide salt in which = CF ₃ and R 2 = CF ₃ was poured into the battery can 1.

  Next, the battery can 1 is caulked through an insulating sealing gasket 10 coated with asphalt to fix the safety valve 8 having a current interrupting mechanism, the heat sensitive resistance element 9 and the battery lid 7 to fix the inside of the battery. Airtightness was maintained. Thus, a cylindrical lithium / iron disulfide primary battery having a diameter of about 10 mm and a height of about 44 mm was produced.

<Example 2 to Example 10>
A lithium / iron disulfide primary battery was prepared in the same manner as in Example 1 except that the addition amount of the chain imide salt in which R1 = CF ₃ and R2 = CF ₃ was changed to the amount shown in Table 1. Produced.

<Example 11 to Example 20>
In the same manner as in Example 1 except that a chain imide salt having R1 = C ₂ F ₅ and R2 = C ₂ F ₅ was added in the addition amount shown in Table 1, Example 11 to Example 1 The lithium / iron disulfide primary battery of Example 20 was fabricated.

<Example 21 to Example 24>
In the chemical formula 1, in the same manner as in Example 1 except that the chain imide salt in which R1 = CF ₃ and R2 = C ₂ F ₅ are added in the amounts shown in Table 1, Examples 21 to 24 A lithium / iron disulfide primary battery was prepared.

<Example 25 to Example 28>
In Example 1, Example 25 to Example were carried out in the same manner as Example 1 except that chain imide salts of R1 = C ₃ F ₇ and R2 = C ₃ F ₇ were added in the amounts shown in Table 1. 28 lithium / iron disulfide primary batteries were prepared.

<Example 29 to Example 32>
In Example 1, Example 29 to Example were carried out in the same manner as Example 1 except that chain imide salts with R1 = C ₄ F ₉ and R2 = C ₄ F ₉ were added in the amounts shown in Table 1. Thirty-two lithium / iron disulfide primary batteries were produced.

<Example 33>
Example 33 was carried out in the same manner as in Example 1 except that LiI was not added and only the chain imide salt in which R1 = CF ₃ and R2 = CF ₃ were added in the amounts shown in Table 1 in Chemical Formula 1. A lithium / iron disulfide primary battery was prepared.

<Example 34>
In the same manner as in Example 1 except that LiI was not added and only the chain imide salt in which R1 = C ₂ F ₅ and R2 = C ₂ F ₅ were added in the amounts shown in Table 1 in Chemical Formula 1 A lithium / iron disulfide primary battery of Example 34 was produced.

<Example 35>
In the same manner as in Example 1 except that LiI was not added and only the chain imide salt in which R1 = CF ₃ and R2 = C ₂ F ₅ were added in the amounts shown in Table 1 in Chemical Formula 1 The lithium / iron disulfide primary battery of Example 35 was produced.

<Example 36>
In the same manner as in Example 1 except that LiI was not added and only the chain imide salt in which R1 = C ₃ F ₇ and R 2 = C ₃ F ₇ were added in the amounts shown in Table 1 in Chemical Formula 1 A lithium / iron disulfide primary battery of Example 36 was produced.

<Example 37>
In the same manner as in Example 1 except that LiI was not added and only the chain imide salt in which R1 = C ₄ F ₉ and R2 = C ₄ F ₉ were added in the amounts shown in Table 1 in Chemical Formula 1 Then, a lithium / iron disulfide primary battery of Example 37 was produced.

<Comparative Example 1>
A lithium / iron disulfide primary battery of Comparative Example 1 was produced in the same manner as in Example 1 except that no chain imide salt was added and only LiI was added in the amount shown in Table 1.

Next, LiSO ₃ CF ₃ was converted to LiSO ₃ CF ₃ in order to confirm the effect of suppressing an increase in open circuit voltage when a mixed salt obtained by mixing the chain imide salt shown in Chemical Formula 1 and LiSO ₃ CF ₄ is included in the electrolyte. The lithium / iron disulfide primary batteries of Examples 38 to 45 and Comparative Example 2 to which the chain imide salt shown in 1 was additionally added were prepared.

<Example 38>
Except that LiSO ₃ CF ₄ was replaced by 1 mol / kg instead of LiI and an electrolytic solution in which a chain imide salt 0.05 mol / kg in which R1 = CF ₃ and R2 = CF ₃ were added in Chemical Formula 1 was prepared The lithium / iron disulfide primary battery of Example 38 was made in the same manner as Example 1.

<Example 39 to Example 41>
In the chemical formula 1, in the same manner as in Example 38, except that the chain imide salt in which R1 = CF ₃ and R2 = CF ₃ were added in the amounts shown in Table 2, the lithium / ion of Examples 39 to 45 was used. An iron disulfide primary battery was produced.

<Example 42 to Example 45>
In Example 1, Example 42 to Example were carried out in the same manner as Example 38, except that chain imide salts with R1 = C ₂ F ₅ and R2 = C ₂ F ₅ were added in the amounts shown in Table 2. Forty-five lithium / iron disulfide primary batteries were fabricated.

<Comparative example 2>
A lithium / iron disulfide primary battery of Comparative Example 2 was produced in the same manner as in Example 1 except that no chain imide salt was added and only LiSO ₃ CF ₄ was added in the amount shown in Table 2.

Next, in order to confirm the effect of suppressing an increase in open circuit voltage when a mixed salt obtained by mixing a chain imide salt and LiClO ₄ is included in the electrolyte, a chain imide salt represented by Chemical Formula 1 is added to LiClO _4. The lithium / iron disulfide primary batteries of Example 46 to Example 53 and Comparative Example 3 which were additionally added were produced.

<Example 46>
Example 1 except that LiClO ₄ 1 mol / kg instead of LiI and a chain imide salt 0.05 mol / kg in which R1 = CF ₃ and R2 = CF ₃ in Chemical Formula 1 were added were prepared In the same manner as in Example 1, a lithium / iron disulfide primary battery of Example 46 was produced.

<Example 47 to Example 49>
In the same manner as in Example 46 except that the chain imide salt in which R1 = CF ₃ and R2 = CF ₃ are added in the amounts shown in Table 3, the lithium / lithium of Examples 47 to 49 is used. An iron disulfide primary battery was produced.

<Example 50 to Example 53>
In the chemical formula 1, Example 50 to Example were carried out in the same manner as in Example 46, except that chain imide salts with R1 = C ₂ F ₅ and R2 = C ₂ F ₅ were added in the amounts shown in Table 2. 53 lithium / iron disulfide primary batteries were prepared.

<Comparative Example 3>
A lithium / iron disulfide primary battery of Comparative Example 3 was produced in the same manner as in Example 1 except that no chain imide salt was added and only LiClO ₄ was added in the amount shown in Table 3.

Measurement of open circuit voltage The lithium / iron disulfide primary batteries of Examples 1 to 53 and Comparative Examples 1 to 3 prepared were predischarged about 10% of the battery capacity, and then room temperature (20 ° C.). Was stored for 1000 hours, and the open circuit voltage of the battery after the storage was measured. Tables 1, 2 and 3 show the measurement results.

Evaluation 1
As shown in Table 1, the open circuit voltages of the batteries of Examples 1 to 37 are lower than those of Comparative Example 1. Therefore, it was found that the increase in the open circuit voltage during storage can be suppressed by including the chain imide salt shown in Chemical Formula 1 in the electrolytic solution. In addition, since the suppression effect is saturated at an addition amount of 1.5 mol / kg, the addition amount of the chain imide salt is within a range where the suppression effect of an increase in open circuit voltage according to the addition amount can be obtained. Therefore, it was found that 0.1 mol / kg to 1.5 mol / kg is preferable.

  The batteries of Examples 1 to 32 use LiI as an electrolyte and an electrolyte prepared by dissolving the chain imide salt shown in Chemical Formula 1 in an organic solvent, and increase in open circuit voltage. Is suppressed. Furthermore, the batteries of Examples 33 to 37 use only a chain imide salt as an electrolyte salt, and an increase in open circuit voltage is suppressed.

  Accordingly, a lithium / iron disulfide primary battery using an electrolytic solution containing only the chain imide salt shown in Chemical Formula 1 and a lithium / iron disulfide using an electrolytic solution containing the chain imide salt and another salt It was found that the primary battery can suppress an increase in open circuit voltage during storage.

Evaluation 2
As shown in Table 2, the open circuit voltages of the batteries of Examples 38 to 45 are lower than those of Comparative Example 2. Therefore, it was found that the lithium / iron disulfide primary battery using the electrolytic solution containing the chain imide salt shown in Chemical Formula 1 and LiSO ₃ CF ₃ can suppress an increase in open circuit voltage during storage. That is, it was found that the lithium / iron disulfide primary battery using the electrolytic solution containing the chain imide salt shown in Chemical Formula 1 and another electrolyte salt can suppress an increase in open circuit voltage during storage.

Evaluation 3
As shown in Table 3, the open circuit voltages of the batteries of Examples 46 to 53 are lower than those of Comparative Example 2. Therefore, it was found that the lithium / iron disulfide primary battery using the electrolytic solution containing the chain imide salt shown in Chemical Formula 1 and LiClO ₄ can suppress an increase in open circuit voltage during storage. That is, it was found that an electrolytic solution using an electrolytic solution containing the chain imide salt shown in Chemical Formula 1 and another electrolyte salt can suppress an increase in open circuit voltage during storage.

  The present invention is not limited to the above-described embodiments of the present invention, and various modifications and applications are possible without departing from the spirit of the present invention.

  For example, in the examples, AAA type lithium / iron disulfide primary batteries were used, but this invention uses dicopper oxide, iron sulfide, iron composite oxide, bismuth trioxide, etc. as the positive electrode active material. As the negative electrode, in addition to lithium, alkali metals such as sodium and those metals are also applicable. In addition to the cylindrical shape, the battery shape is applicable to a button shape, a coin shape, a square shape, and the like.

1 is a cross-sectional side view showing a structure of a lithium / iron disulfide primary battery according to an embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Battery can 2 ... Positive electrode 3 ... Negative electrode 4 ... Separator 5 ... Insulating plate 6 ... Insulating plate 7 ... Battery cover 8 ... Safety valve 9 ... Hot feeling Resistance element 10 ... Sealing gasket 11 ... Positive electrode lead 12 ... Negative electrode lead

Claims (3)

A positive electrode using iron disulfide as a positive electrode active material;
A negative electrode using lithium as a negative electrode active material;
A lithium / iron disulfide primary battery comprising an electrolyte solution,
The lithium / iron disulfide primary battery, wherein the electrolytic solution contains a chain imide salt represented by the following chemical formula.

(Wherein R1 represents C _n F _{2n + 1} and R2 represents C _m F _{2m + 1} ) In claim 1,
The lithium / iron disulfide primary battery in which R1 and R2 in Chemical Formula 1 are selected from CF ₃ , C ₂ F ₅ , C ₃ F ₇ , and C ₄ F ₉ . In claim 1,
The lithium / iron disulfide primary battery, wherein the chain imide salt is contained in the electrolytic solution in an amount of 0.1 mol / kg to 1.5 mol / kg.

Images