JP2005310424A - Non-aqueous electrolytic solution battery and its battery case material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a non-aqueous electrolytic solution battery which suppresses the deterioration of the battery caused by the corrosion of a battery case in long term storage, in particular, which is improved in the corrosion resistance of the battery case in a high humid environment, and highly reliable. <P>SOLUTION: As a material of the battery case of a non-aqueous electrolytic solution battery, a nickel alloy containing Cr 22-25 wt%, molybdenum 6.5-9.0 wt%, N 0.15-0.25 wt%, and Fe 30-39 wt% and the remainder Ni and other impurities is used. Especially, when the positive electrode material is a 4V class lithium contained transition metal oxide, and the solute of the electrolytic solution is LiPF<SB>4</SB>, LiBF<SB>4</SB>, or a mixture of LiPF<SB>6</SB>and LiBF<SB>4</SB>, a remarkable improvement in corrosion resistance is made. As a suitable gasket material, at least one resin of PPS, PFA or ETFA is used. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a nonaqueous electrolyte battery, and more particularly to a metal material for a battery case.

  In the non-aqueous electrolyte battery, an organic solvent is used as a solvent for the electrolyte solution. Therefore, a battery having a high voltage and a high capacity can be obtained by appropriately selecting the positive electrode active material.

In such a non-aqueous electrolyte battery, the battery case that is in direct contact with the positive electrode directly or indirectly through a lead or the like has a high battery case during continuous charging of the battery or storage under no load. It is easily corroded electrochemically because of its potential. For this reason, a material excellent in corrosion resistance having a higher potential than the positive electrode active material is used. So far, ferritic stainless steel and austenitic stainless steel have been proposed and widely used. (For example, see Patent Document 1 or Patent Document 2)
JP-A-7-94212 Japanese Patent No. 3195475

However, when storing in a humid environment, when moisture enters the inside of the battery, there is a problem that the moisture serves as a catalyst to accelerate the corrosion of the battery case and accelerate the deterioration of the battery. In particular, even when these stainless steels are used as the battery case material of a non-aqueous electrolyte battery in which the open circuit voltage of the positive electrode is 4 V (vs. Li / Li ⁺ ) or more, the battery case is completely dissolved during long-term storage. It was not something that could be prevented. Furthermore, although the corrosion resistance can be improved by increasing the addition amount of chromium and molybdenum, there has been a problem that the material hardness is increased, the workability is deteriorated, and the liquid resistance is impaired in long-term storage.

  Therefore, improving the corrosion resistance without impairing the workability of the battery case is considered an urgent need to increase the reliability of this type of battery as a practical battery.

  The present invention has been made to address the above problems, and can suppress the deterioration of the battery due to the corrosion of the battery case during long-term storage. In particular, the corrosion resistance of the battery case in a humid environment is improved, and the reliability is improved. An object of the present invention is to provide a nonaqueous electrolyte battery having a high level.

  In order to achieve the above object, the present invention provides a battery case material comprising 22 to 25% by weight of chromium, 6.5 to 9.0% by weight of molybdenum, 0.15 to 0.25% by weight of nitrogen and iron. Is 30 to 39% by weight, and the balance is nickel alloy composed of nickel and other impurities.

  Further, the non-aqueous electrolyte battery of the present invention is a battery in which a positive electrode, a negative electrode, a separator, and an electrolytic solution are housed in a battery container composed of a battery case, a sealing plate, and a resin gasket. It contains 22-25% by weight of chromium, 6.5-9.0% by weight of molybdenum, 0.15-0.25% by weight of nitrogen and 30-39% by weight of iron, with the balance being nickel and other impurities. A nickel alloy is used.

This nickel alloy more preferably contains 33 to 37% by weight of nickel.

Further, when LiPF ₆ , LiBF _4, or a mixture of LiPF ₆ and LiBF ₄ is used as the solute of the electrolytic solution, LiN (C ₂ F ₅ SO ₂ ) ₂ or LiN (CF ₃ SO ₂ ) ₂ Compared with the case where is used, the degree of progress of corrosion of the battery case in a humid environment is greatly improved.

  Further, a suitable resin for the gasket includes at least one resin of polyphenylene sulfide, perfluoroalkoxyalkane or ethylene-tetrafluoroethylene copolymer.

  In stainless steel, it is known that the inclusion of chromium and molybdenum is very effective for corrosion resistance. This is because chromium or molybdenum reacts with oxygen or moisture in the air to form a passive film of oxide or hydroxide, and this film is formed on the surface of stainless steel to suppress the progress of corrosion. However, when a large amount of chromium and molybdenum is contained, there is a problem that the material hardness increases and the workability deteriorates. On the other hand, as a result of various examinations, it contains 22 to 25% by weight of chromium, 6.5 to 9.0% by weight of molybdenum, 0.15 to 0.25% by weight of nitrogen and 30 to 39% by weight of iron. In addition, it was found that when a nickel alloy consisting of nickel and other impurities is used as the balance, high corrosion resistance can be obtained without impairing workability as compared with conventional ferritic stainless steel and austenitic stainless steel.

  It has been found that the nickel alloy of the present invention can obtain higher corrosion resistance when it contains 33 to 37% by weight of nickel.

In addition, as information terminals such as mobile phones and PDAs become highly functional, demand for nonaqueous electrolyte batteries using LiCoO ₂ , LiNiO _2, LiMn ₂ O ₄ or the like having a high potential as a positive electrode material is increasing. However, when a 4V-class lithium-containing transition metal oxide such as LiCoO ₂ , LiNiO ₂ or LiMn ₂ O ₄ (a material in which the open circuit voltage of the positive electrode is 4 V or more (vs. Li ^/ Li ⁺ )) is used as the positive electrode active material In this case, the potential of the positive electrode is 4 V or more (vs. Li ^/ Li ⁺ ), and stainless steel that has been widely used as a battery case material in the past cannot completely prevent corrosion of the battery case during long-term storage. There was a need for further long-term reliability improvements. Therefore, when the steel material of the present invention is used for a battery case of a non-aqueous electrolyte battery using a 4V-class positive electrode material such as LiCoO ₂ , LiNiO ₂ or LiMn ₂ O _{4, the} pitting potential is higher than that of conventional stainless steel. Therefore, corrosion can be suppressed even at a high potential exceeding 4 V, and improvement in long-term reliability can be achieved.

Further, LiPF ₆ and LiBF ₄ are excellent in electric conductivity, thermal stability and oxidation resistance, and are relatively inexpensive and are often used in non-aqueous electrolyte batteries. However, in a battery using LiPF ₆ or LiBF ₄ as the electrolyte solute, when moisture enters the battery, LiPF ₆ or LiBF ₄ reacts with the intruded moisture and dissociates halogen ions. This halogen ion locally destroys the passive film formed on the surface of the steel to cause local corrosion and accelerate battery deterioration.

Therefore, when a battery using LiPF ₆ or LiBF ₄ as the solute of the electrolyte is used in a humid environment, there is a problem in long-term reliability and the like, and there is a big problem in practical use. Therefore, when the nickel alloy of the present invention is used in a battery case of a non-aqueous electrolyte battery using LiPF ₆ , LiBF ₄ or a mixture of LiPF ₆ and LiBF ₄ in the electrolyte solute, the content of chromium and molybdenum Therefore, the ability to form a passive film is improved, and the formation of a dense film suppresses local corrosion of the steel surface by halogen ions, improving the corrosion resistance of the battery case. Long-term reliability in the environment can be improved.

  It is also preferable to use at least one resin of polyphenylene sulfide, perfluoroalkoxyalkane or ethylene-tetrafluoroethylene copolymer for the gasket. Compared to polypropylene, which has been widely used as a gasket material, the resin has a low water vapor permeability, so that the amount of moisture entering the battery can be reduced.

  According to the present invention, it is possible to provide a highly reliable non-aqueous electrolyte battery with which the battery case is unlikely to corrode, and the corrosion of the battery case in which moisture becomes a catalyst can be suppressed particularly when stored in a humid environment.

  The present invention is applicable to both primary batteries and secondary batteries. The gist of the present invention is a battery case material of a nonaqueous electrolyte battery, and conventionally known materials can be used for members other than these without particular limitation.

  FIG. 1 is a cross-sectional view of a nonaqueous electrolyte battery according to an embodiment of the present invention.

  In FIG. 1, reference numeral 1 denotes a battery case that also serves as a positive electrode terminal. This battery case 1 has 22-25% by weight of chromium (Cr), 6.5-9.0% by weight of molybdenum (Mo), 0.15-0.25% by weight of nitrogen (N) and iron (Fe ) In a content of 30 to 39% by weight, and the balance is nickel (Ni) and other impurities, and is higher than conventional ferritic stainless steel and austenitic stainless steel without sacrificing workability. Corrosion resistance can be obtained.

  Examples of the other impurities include carbon (C), silicon (Si), manganese (Mn), phosphorus (P), and sulfur (S). This does not particularly define the amount of the component, and it is sufficient that the amount is small enough not to impede the action of the present invention, and includes impurities that are inevitably mixed.

  Here, when 33 to 37% by weight of Ni is contained, higher corrosion resistance can be obtained. This is because Ni does not contribute to the formation of a surface passive film, but has a function of suppressing the progress of corrosion due to the high corrosion resistance of Ni. However, the inclusion of a large amount of Ni increases the hardness of the steel material, and the workability deteriorates. However, as a result of various studies, if Ni is contained in an amount of 33 to 37% by weight, higher corrosion resistance is obtained without impairing the workability. I found out that

  A sealing plate 2 also serves as a negative electrode terminal, and stainless steel is usually used. In addition, when the nickel alloy of the present invention is used for this sealing plate, a non-aqueous electrolyte battery having higher corrosion resistance can be obtained.

  3 is a gasket that insulates the case from the sealing plate. Since at least one resin of polyphenylene sulfide, perfluoroalkoxyalkane, or ethylene-tetrafluoroethylene copolymer has a low water vapor permeability, In storage, the amount of moisture permeating into the battery can be reduced, and the corrosion of the battery case in which moisture becomes a catalyst can be suppressed, which is preferable.

4 is a positive electrode, and examples of the positive electrode active material include materials that form an intercalation compound with lithium ions, such as metal oxides such as V ₂ O ₅ , Nb ₂ O ₂ , and MnO ₂ , and LiCoO ₂ , LiNiO _2. Or 4V grade lithium-containing transition metal oxides such as LiMn ₂ O ₄ are suitable,
It is also preferable that magnesium or aluminum is added to these oxides.

Here, when a 4V-class lithium-containing transition metal oxide such as LiCoO ₂ , LiNiO ₂ or LiMn ₂ O ₄ is used as the positive electrode active material, Cr is 22 to 25 wt% and Mo is 6.5 to 9.0. When a nickel alloy containing 0.1% to 0.25% by weight of N and 0.1% to 0.25% by weight of Fe and 30 to 39% by weight of Fe and the balance being Ni and other impurities is used as a battery case material, conventional ferritic stainless steel, Compared with austenitic stainless steel, since it has a noble potential higher than that of the positive electrode active material, a significant improvement in corrosion resistance can be seen.

  Reference numeral 5 denotes a negative electrode, and examples of the negative electrode active material include a material capable of electrochemically inserting and extracting lithium ions and lithium metal. As a substance capable of electrochemically inserting and extracting lithium ions, for example, a base metal oxide, a carbon material such as graphite or coke, or a lithium-aluminum alloy, compared to a positive electrode active material such as lithium titanate, Examples include lithium alloys such as lithium-lead alloys and lithium-tin alloys.

  6 is a separator usually made of a nonwoven fabric made of polypropylene, and 7 is a positive electrode current collector. Although not shown, an electrolytic solution composed of an organic solvent and a lithium salt is enclosed.

  Hereinafter, embodiments of the present invention will be described more specifically with reference to the drawings and tables.

(Experiment 1)
A nonaqueous electrolyte battery having the structure of FIG. 1 was prepared. The battery case 1 was made of the materials shown in (Table 1) described later. The sealing plate 2 was made of stainless steel SUS316 according to JIS standards. A polypropylene gasket was used as the gasket 3 for insulating the case and the sealing plate. The positive electrode 4 is obtained by mixing LiCoO ₂ which is a 4V class active material with carbon black as a conductive agent and fluororesin powder as a binder, and forming into a pellet shape with a diameter of 10 mm and a thickness of 0.5 mm at 250 ° C. What was dried for 24 hours was used.

  The negative electrode 5 is obtained by adding styrene butadiene rubber as a binder to graphitized mesophase pitch carbon fiber powder, diluting and mixing with ion-exchanged water, and forming into a pellet shape having a diameter of 11 mm and a thickness of 0.5 mm, at 150 ° C. What was dried for 24 hours was used.

  Further, the nonwoven fabric made of polypropylene was used for the separator 6. As the positive electrode current collector 7, a conductive carbon paint was applied to the inner surface of the case 1 and then the case was dried at 150 ° C. for 6 hours in order to remove moisture from the coating film. In addition, as an electrolytic solution, a solute shown in (Table 2) and (Table 3) described later in a solvent in which ethylene carbonate and methyl ethyl carbonate are mixed at a volume ratio of 1: 3 at a ratio of 1 mol / l. The dissolved one was used.

  Each finished battery has a diameter of 16 mm and a thickness of 1.6 mm. These batteries were first charged (protective resistance 50Ω) for 24 hours at a constant voltage of 4.2 V after assembling. These discharge capacities were measured for those stored for 40 days immediately after the initial charge and in a state where a constant voltage of 4.2 V was applied in a high-temperature and high-humidity environment at 60 ° C. and 90% to determine the remaining capacity ratio (%). . The discharge capacity is a constant resistance discharge of 2 kΩ up to 3.0 V, and the capacity at this time is calculated.

Further, as a positive electrode, a carbon black as a conductive agent and a fluorine resin powder as a binder are mixed with Li _0.3 MnO ₂ as a 3.0 V class active material or V ₂ O ₅ as a 3.5 V class active material, and a diameter of 10 mm. The experiment was conducted except that a metal lithium punched to a diameter of 10 mm and a thickness of 0.2 mm was pressure-bonded to the inner surface of the sealing plate after being molded into a pellet having a thickness of 0.5 mm and dried at 250 ° C. for 24 hours. A battery was assembled in the same manner as in 1.

For these batteries, batteries using Li _0.3 MnO ₂ as the active material were discharged at 3.0 mA for 3 hours, and then charged at a constant voltage of 3.1 V for 24 hours (protection resistance 50Ω). These discharge capacities were measured for those stored for 40 days under the condition of applying a constant voltage of 3.1 V immediately after the initial charge and in a high-temperature and high-humidity environment at 60 ° C. and 90% to determine the remaining capacity ratio (%). .

  The discharge capacity is a constant resistance discharge of 2 kΩ up to 2.0 V, and the capacity at this time is calculated.

Further, a battery using V ₂ O ₅ as an active material was discharged at 3.0 mA for 3 hours, and then charged at a constant voltage of 3.6 V for 24 hours (protection resistance 50Ω). These discharge capacities were measured for each of those stored for 40 days immediately after the initial charge and in a state where a constant voltage of 3.6 V was applied in a high-temperature and high-humidity environment at 60 ° C. and 90% to determine the remaining capacity ratio (%). .

  The discharge capacity is obtained by performing a constant resistance discharge of 2 kΩ up to 2.5 V and calculating the capacity at this time.

  In addition, after the test, the battery was disassembled, and the location of corrosion inside the battery case was observed using a digital microscope. Furthermore, the corrosion depth was measured using a surface roughness meter.

  Table 1 shows the composition of the battery case used in this experiment expressed as a percentage by weight.

  Example 1 contains 22.2 wt% Cr, 6.8 wt% Mo, 0.15 wt% N, 37.5 wt% Fe, 32.8 wt% Ni, the balance being other impurities A nickel alloy consisting of

  Example 2 contains 24.3% by weight of Cr, 6.5% by weight of Mo, 0.18% by weight of N, 39.0% by weight of Fe and 29.9% by weight of Ni, with the remainder being other impurities. A nickel alloy consisting of

  Example 3 contains 24.2% by weight of Cr, 7.2% by weight of Mo, 0.20% by weight of N, 36.8% by weight of Fe and 31.4% by weight of Ni, with the remainder being other impurities. A nickel alloy consisting of

  Example 4 contains 24.8% by weight of Cr, 8.2% by weight of Mo, 0.23% by weight of N, 37.7% by weight of Fe and 28.9% by weight of Ni, with the remainder being other impurities. A nickel alloy consisting of

  Example 5 contains 23.3% by weight of Cr, 7.5% by weight of Mo, 0.22% by weight of N, 33.4% by weight of Fe and 35.5% by weight of Ni, with the remainder being other impurities. A nickel alloy consisting of

  Example 6 contains 22.1% by weight of Cr, 6.3% by weight of Mo, 0.19% by weight of N, 38.0% by weight of Fe and 33.3% by weight of Ni, with the remainder being other impurities A nickel alloy consisting of

Example 7 contains 24.9% by weight of Cr, 8.5% by weight of Mo, 0.16% by weight of N, 30.0% by weight of Fe and 36.3% by weight of Ni, with the remainder being other impurities. A nickel alloy consisting of

  Further, SUS316 stainless steel in JIS standard as Comparative Example 1, SUS304 stainless steel in JIS Standard as Comparative Example 2, SUS444 stainless steel in JIS Standard as Comparative Example 3, SUS447J1 in JIS Standard as Comparative Example 4 Stainless steel was used as Comparative Example 5 as SUS317J4L stainless steel in JIS standards.

  (Table 2) and (Table 3) show materials, positive electrode active materials, solutes, residual capacity ratios, corrosion rates, and corrosion depths used for the battery cases of the test batteries. The remaining capacity ratio was determined by measuring 10 batteries and calculating the average value. The corrosion rate is represented by “×” for general corrosion, “Δ” for partial corrosion, and “◯” for no corrosion. The corrosion depth was determined by measuring 10 batteries, and taking the average value.

  As can be seen from the results of (Table 2) and (Table 3), the batteries (A1 to A32) using the battery case made of the nickel alloy of Examples 1 to 7 are made of the stainless steel of Comparative Examples 1 to 5 as the battery case. As compared with the batteries (B1 to B24) used in the above, the decrease in the remaining capacity ratio was reduced. From this, it can be seen that the use of the nickel alloy of the present invention for a battery case can suppress the deterioration of the positive electrode reaching a high potential in a high temperature and high humidity environment.

  In addition, as a result of disassembling and investigating after the test, the batteries B1 to B20 were corroded on the inner surface of the case, and this was caused by the decrease in capacity.

  Further, in the batteries (A1 to A4, A8 to A11, A15 to A18, A22 to A25, A29, and A31) using the battery case made of the nickel alloy of Examples 1 to 4, a battery in which partial corrosion occurs. (A2, A4, A9, A10, A16 and A23) can be seen, but batteries (A5 to A7, A12 to A14, A19 to A21, A26) using battery cases made of nickel alloys of Examples 5 to 7 ~ A28, A30, A32) all showed no corrosion. From this, it can be seen that the nickel alloys of Examples 5 to 7 exhibit higher corrosion resistance.

Also, batteries using LiCoO ₂ with positive electrode potential of 4 V or more (A1 to A7, B1 to B5) and batteries using Li _0.3 MnO ₂ or V ₂ O ₅ of 4 V or less (A29 to When A32, B21 to B24) are compared, in the battery using LiCoO ₂ as the positive electrode, the nickel alloy of Examples 1 to 7 is used for the battery case, which is much larger than the case of using the stainless steel of Comparative Examples 1 to 5. It can be seen that the decrease in the remaining capacity ratio is reduced. Furthermore, looking at the corrosion rate and the corrosion depth, when the nickel alloy of Examples 1 to 7 is used for the positive electrode case in the battery using LiCoO ₂ as the positive electrode, compared to the case of using the stainless steel of Comparative Examples 1 to 5, It can be seen that the corrosion is greatly suppressed.

Similar results were obtained when LiNiO ₂ or LiMn ₂ O ₄ which is the same 4V-class lithium-containing transition metal oxide as LiCoO ₂ was used as the positive electrode active material.

Further, in each solute, the difference between the remaining capacity ratio when using the nickel alloys of Examples 1 to 7 and the remaining capacity ratio when using the stainless steels of Comparative Examples 1 to 5 (for example, the solute is LiPF ₆ ). In this case, when comparing the remaining capacity ratios of the batteries A1 to A7 and the remaining capacity ratios of the batteries B1 to B5, LiN (C ₂ F ₅ SO ₂ ) ₂ or LiN (CF ₃ SO ₂ ) ₂ is used. It can be seen that the residual capacity rate is significantly recovered when LiPF ₆ or LiBF ₄ is used as the solute. In addition, when LiPF ₆ or LiBF ₄ is used as the solute, the residual capacity ratio is higher than that when LiN (C ₂ F ₅ SO ₂ ) ₂ or LiN (CF ₃ SO ₂ ) ₂ is used, which is excellent. The characteristics are shown. In particular, when the nickel alloys of Examples 5 to 7 are used, the remaining capacity ratio of 90% or more is maintained. This is due to the fact that LiPF ₆ or LiBF ₄ has better oxidation resistance than LiN (C ₂ F ₅ SO ₂ ) ₂ or LiN (CF ₃ SO ₂ ) _2. It is effective to use LiPF ₆ or LiBF ₄ as a solute for a battery having a voltage of 4 V or more. When the nickel alloy of Examples 1 to 7 is used for a positive electrode case, corrosion under a humid environment is suppressed, and a high remaining capacity ratio is obtained. You can see that The same result is obtained even when a solute in which LiPF ₆ and LiBF ₄ are mixed is used.

Further, in each solute, the difference between the corrosion depth when the nickel alloys of Examples 1 to 7 are used and the corrosion depth when the stainless steels of Comparative Examples 1 to 5 are used (for example, when the solute is LiPF ₆ ). Is the difference between the corrosion depth of the batteries A2 and A4 and the corrosion depth of B1 to B5), compared to the case of using LiN (C ₂ F ₅ SO ₂ ) ₂ or LiN (CF ₃ SO ₂ ) ₂ It can also be seen that corrosion is greatly suppressed when LiPF ₆ or LiBF ₄ is used as the solute.

Similar results were obtained even when a mixed solute of LiPF ₆ and LiBF ₄ was used.
(Experiment 2)
The battery case 1 contains 23.3 wt% Cr, 7.5 wt% Mo, 0.22 wt% N, 33.4 wt% Fe, and 35.5 wt% Ni. The balance is made of nickel alloy consisting of the impurities, the sealing plate 2 is made of stainless steel SUS316 according to JIS standards, the resin gasket is made of polyphenylene sulfide (PPS), and the battery is made of A33, perfluoroalkoxyalkane (PFA). Experiment 1 except that the battery was A34, the battery made of ethylene-tetrafluoroethylene copolymer (ETFE) was A35, and the battery using polypropylene (PP) widely used as a gasket material was A36.
The battery was assembled and charged in the same manner as described above.

As in Experiment 1, the discharge capacities of these batteries were measured for those stored for 100 days immediately after initial charge and under a high temperature and humidity environment of 60 ° C. and 90% with a constant voltage of 4.2 V applied. The remaining capacity ratio (%) was determined. Discharge capacity is 3.0k for constant resistance discharge of 2kΩ
This is performed up to V, and the capacity at this time is calculated.

  Table 4 shows the gasket material, solute, and remaining capacity rate used for each test battery. The remaining capacity ratio was determined by measuring 10 batteries and calculating the average value.

From these results, when using at least one resin of PPS, PFA or ETFA as a resin gasket, compared with the case of using polypropylene, which has been widely used as a gasket material, it has a higher potential in a high temperature and humidity environment. It can be seen that the deterioration of the positive electrode that has reached can be suppressed. The same result can be obtained even when LiNiO ₂ or LiMn ₂ O ₄ is used as the positive electrode active material, or when LiBF ₄ or a mixture of LiPF ₆ and LiBF ₄ is used as the solute.

  The non-aqueous electrolyte battery of the present invention is useful as a main power source or backup power source for electronic devices and the like.

Sectional drawing of the battery in the Example of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Battery case 2 Sealing plate 3 Gasket 4 Positive electrode 5 Negative electrode 6 Separator 7 Positive electrode collector

Claims (6)

It contains 22-25% by weight of chromium, 6.5-9.0% by weight of molybdenum, 0.15-0.25% by weight of nitrogen and 30-39% by weight of iron, with the balance being nickel and other impurities. A battery case material for a non-aqueous electrolyte battery using a nickel alloy.   A non-aqueous electrolyte battery in which a positive electrode, a negative electrode, a separator, and an electrolytic solution are housed in a battery container including a battery case, a sealing plate, and a resin gasket, and 22 to 25% by weight of chromium as a material of the battery case, A nickel alloy containing 6.5 to 9.0% by weight of molybdenum, 0.15 to 0.25% by weight of nitrogen and 30 to 39% by weight of iron, with the balance being nickel and other impurities is used. Non-aqueous electrolyte battery.   The non-aqueous electrolyte battery according to claim 2, wherein the nickel alloy contains 33 to 37 wt% of the nickel.   4. The nonaqueous electrolyte battery according to claim 2, wherein the positive electrode material comprises a transition metal oxide containing 4 V class lithium having an open circuit voltage of 4 V or more when metallic lithium is used as a counter electrode. 5. The nonaqueous electrolyte battery according to claim ₄ , wherein a solute of the electrolyte is LiPF ₆ and / or LiBF ₄ . The non-aqueous electrolyte battery according to claim 5, wherein the gasket is made of at least one resin of polyphenylene sulfide, perfluoroalkoxyalkane, or ethylene-tetrafluoroethylene copolymer.

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