JP6253571B2 - Non-aqueous electrolyte battery - Google Patents

Description

  The present invention relates to a non-aqueous electrolyte battery excellent in heavy load discharge characteristics.

  Non-aqueous electrolyte batteries have been conventionally applied to many uses that perform continuous discharge at a relatively light load, but in recent years, they have also been applied to uses that require heavy load discharge. Accordingly, improvement of heavy load discharge characteristics is also demanded.

  One of the techniques for improving the characteristics of the non-aqueous electrolyte battery is to improve the non-aqueous electrolyte. For example, by using a nitrile solvent with a high dielectric constant and low viscosity as the solvent for the non-aqueous electrolyte, the solubility of the lithium salt in the non-aqueous electrolyte and the movement of lithium ions in the non-aqueous electrolyte Therefore, the use of such a non-aqueous electrolyte can be expected to improve the heavy load discharge characteristics of the non-aqueous electrolyte battery.

  By the way, Li (lithium) metal is often used as a negative electrode active material of a non-aqueous electrolyte battery such as a coin-type lithium battery, but a nitrile solvent has high reactivity with Li metal. Therefore, it is difficult to use only the nitrile solvent as the nonaqueous electrolyte solvent, and it is necessary to use it together with other solvents.

  As another solvent used in combination with the nitrile solvent, ethylene carbonate or propylene carbonate having a high dielectric constant is preferable. However, these solvents have low affinity with polyolefin separators usually used in non-aqueous electrolyte batteries. Therefore, in a battery using a non-aqueous electrolyte prepared by using the above-mentioned solvent together with a nitrile solvent, the non-aqueous electrolyte is difficult to permeate into the separator. The heavy load discharge characteristics cannot be sufficiently ensured.

  For these reasons, when ethylene carbonate, propylene carbonate, or the like is used as a solvent for a non-aqueous electrolyte, it is generally performed to use a low-viscosity chain carbonate or the like together.

  On the other hand, in order to increase the permeability of the non-aqueous electrolyte solvent to the separator, it is also conceivable that the separator is treated to increase the affinity with the non-aqueous electrolyte solvent. For example, Patent Document 1 proposes a technique of using a polyolefin-based non-woven fabric that has been lyophilically surface-modified, that is, hydrophilized, as a non-woven fabric of a separator for a flat alkaline primary battery.

JP 2009-64672 A

  However, moisture is easily adsorbed by the separator subjected to the hydrophilic treatment, and the amount of moisture introduced into the battery increases by using such a separator. The battery described in Patent Document 1 is an alkaline primary battery, and since an alkaline aqueous solution is used as the electrolytic solution, the battery characteristics are not affected even if the amount of moisture adsorbed by the separator is increased. In this case, when the amount of moisture introduced increases, Li as the negative electrode active material is deactivated, so that the battery characteristics are deteriorated.

  For these reasons, when a nitrile solvent is used as a non-aqueous electrolyte solvent for a non-aqueous electrolyte battery, development of a technique for suppressing the occurrence of the above-described problems is required.

  This invention is made | formed in view of the said situation, The objective is to provide the nonaqueous electrolyte battery excellent in the heavy load discharge characteristic.

  The non-aqueous electrolyte battery of the present invention that has achieved the above object has a positive electrode, a negative electrode, a separator, and a non-aqueous electrolyte, and the negative electrode contains a Li-Al alloy, , A porous membrane containing a resin with a wetting index of 30 to 45 mN / m, and has been hydrophilized, and the non-aqueous electrolyte is an organic solvent other than a nitrile solvent and the nitrile solvent. It is a solvent and contains a solvent (A) having a surface tension of 25 to 45 mN / m.

  ADVANTAGE OF THE INVENTION According to this invention, the nonaqueous electrolyte battery excellent in the heavy load discharge characteristic can be provided.

It is a longitudinal section showing typically an example of the nonaqueous electrolyte battery of the present invention.

  The non-aqueous electrolyte battery of the present invention uses a solution obtained by dissolving an electrolyte salt such as a lithium salt in an organic solvent as the non-aqueous electrolyte. As the organic solvent, a nitrile solvent and a solvent other than the nitrile solvent are used.

  Examples of nitrile solvents include acetonitrile, propionitrile, butyronitrile, valeronitrile, benzonitrile, acrylonitrile and other mononitriles; malononitrile, succinonitrile, glutaronitrile, adiponitrile, 1,4-dicyanoheptane, 1,5-dicyano Pentane, 1,6-dicyanohexane, 1,7-dicyanoheptane, 2,6-dicyanoheptane, 1,8-dicyanooctane, 2,7-dicyanooctane, 1,9-dicyanononane, 2,8-dicyanononane, 1 , 10-dicyanodecane, 1,6-dicyanodecane, dinitriles such as 2,4-dimethylglutaronitrile; cyclic nitriles such as benzonitrile; alkoxy-substituted nitriles such as methoxyacetonitrile; Only seed It may have, may be used in combination of two or more thereof. Among these, mononitrile is more preferable, and acetonitrile is still more preferable.

  Moreover, the solvent (A) whose surface tension is 25-45 mN / m is used for solvents other than a nitrile solvent. As will be described later, the non-aqueous electrolyte battery of the present invention uses a porous membrane containing a resin having a wetting index of 30 to 45 mN / m as a separator. If it is a solvent (A) which has tension | tensile_strength, the permeability to such a separator is favorable and the improvement effect of the heavy load discharge characteristic of a battery by using a nitrile type solvent can be ensured favorably.

  The surface tension of the solvent (A) as used herein is a value measured by a Wilhelmy method using a commercially available apparatus (for example, “CBVP-Z” manufactured by Kyowa Interface Science Co., Ltd.).

  The solvent (A) preferably has a high dielectric constant, and specifically has a dielectric constant of 30 to 110. Specific examples of the solvent (A) having such a high dielectric constant include ethylene carbonate (EC, surface tension 44 mN / m, dielectric constant at 80 ° C., 89.6), propylene carbonate (PC, surface tension 40.9 mN). / M, dielectric constant at 23 ° C. 69.0), dimethyl sulfoxide (DMSO, surface tension 43.5 mN / m, dielectric constant 46.45), γ-butyrolactone (GBL, surface tension 43.9 mN / m, dielectric) Rate 39.1) and the like, and only one of these may be used, or two or more may be used in combination.

  In addition, since nitrile solvents generally have a low boiling point, when a nonaqueous electrolyte battery using a nonaqueous electrolyte containing this is used in a high temperature environment, the nitrile solvent evaporates and causes swelling of the battery, etc. It may cause a decrease in storage characteristics of the battery. However, since the exemplified solvent (A) has a high boiling point, the combined use with a nitrile solvent suppresses the amount of gas generated due to vaporization of the nonaqueous electrolyte solvent in the nonaqueous electrolyte battery, and the storage characteristics of the battery It is also possible to suppress the occurrence of lowering.

  In addition to the nitrile solvent and the solvent (A), other organic solvents can be used as the organic solvent of the nonaqueous electrolytic solution.

  Other solvents used together with the nitrile solvent and the solvent (A) include those having a surface tension other than 25 to 45 mN / m, such as dimethyl carbonate (DMC), diethyl carbonate (DEC), and dimethoxyethane (DME). Can be used.

  In the total amount of the organic solvent contained in the nonaqueous electrolytic solution, the content of the nitrile solvent is preferably 20% by mass or more from the viewpoint of favorably ensuring the effect of improving the heavy load discharge characteristics of the battery due to its use, It is more preferable that it is 40 mass% or more. On the other hand, by limiting the amount of nitrile solvent in the non-aqueous electrolyte, it is possible to satisfactorily suppress deterioration of battery storage characteristics due to excessive reaction between Li and the non-aqueous electrolyte solvent and vaporization of the nitrile solvent. From the viewpoint, the content of the nitrile solvent in the total amount of the organic solvent contained in the nonaqueous electrolytic solution is preferably 60% by mass or less, and more preferably 45% by mass or less.

  Further, in the total amount of the organic solvent contained in the non-aqueous electrolyte, the content of the solvent (A) is the storage characteristics of the battery due to excessive reaction between Li and the non-aqueous electrolyte solvent or vaporization of the nitrile solvent. From the viewpoint of satisfactorily suppressing the decrease in the amount, it is preferably 5% by mass or more, more preferably 20% by mass or more. On the other hand, if the amount of the solvent (A) in the non-aqueous electrolyte is too large, for example, the amount of the nitrile solvent decreases, and the effect of improving the heavy load discharge characteristics of the battery may be reduced. Therefore, the content of the solvent (A) in the total amount of the organic solvent contained in the nonaqueous electrolytic solution is preferably 60% by mass or less, and more preferably 55% by mass or less.

  Further, when a solvent other than the nitrile solvent and the solvent (A) is used as the organic solvent of the nonaqueous electrolytic solution, the nitrile solvent and the solvent (A) in the total amount of the organic solvent contained in the nonaqueous electrolytic solution. The content is preferably used in a range that satisfies the above-mentioned preferred values.

Examples of the lithium salt dissolved in the nonaqueous electrolyte solution, for _{example, LiBF 4, LiPF 6, LiAsF} 6, LiSbF 6, LiClO 4, LiC n F 2n + 1 SO 3 (n ≧ 1) [LiCF 3 SO 3, LiC 4 F 9 SO ₃ etc.], lithium imide salt [LiN (CF ₃ SO ₂ ) ₂ , LiN (C ₂ F ₅ SO ₂ ) ₂ etc.], LiC (CF ₃ SO ₂ ) ₃ , LiCF ₃ CO ₂ , LiB ₁₀ Cl ₁₀ , Examples include lithium lower fatty acid carboxylate, LiAlCl ₄ , LiCl, LiBr, LiI, chloroborane lithium, lithium tetraphenylborate and the like, and at least one of them is used.

  Although the density | concentration of the lithium salt in a non-aqueous electrolyte is not specifically limited, 0.2-2 mol / l is preferable and 0.3-1.5 mol / l is more preferable.

  In addition, the non-aqueous electrolyte may be used as a non-aqueous electrolyte battery after being gelled (gel-like electrolyte) with a polymer or the like.

  It is preferable that vinylene carbonate (VC) is added to the non-aqueous electrolyte. By using the non-aqueous electrolyte to which VC is added, a film is formed on the surface of the negative electrode, and this film suppresses the deactivation of Li due to moisture, so that the heavy load discharge characteristics of the battery are further improved.

  The content of VC in the non-aqueous electrolyte used in the battery is preferably 2% by mass or more, and more preferably 10% by mass or more, from the viewpoint of ensuring the above-described effects due to its use. However, if the amount of VC in the non-aqueous electrolyte is too large, the film formed on the negative electrode surface becomes too thick, which may cause an increase in internal resistance. Therefore, the content of VC in the nonaqueous electrolytic solution used for the battery is preferably 7% by mass or less, and more preferably 5% by mass or less.

  The non-aqueous electrolyte battery of the present invention uses a separator obtained by subjecting a porous film containing a resin having a wetting index of 30 to 45 mN / m to a hydrophilic treatment. The porous membrane containing the resin having the wetting index is generally used as a separator of a non-aqueous electrolyte battery, but the non-aqueous electrolyte containing the solvent (A) together with the nitrile solvent is The affinity with such a separator is low, and it is difficult to penetrate into the voids of this separator. Therefore, in the non-aqueous electrolyte battery of the present invention, the porous membrane is subjected to a hydrophilization treatment and the non-aqueous electrolyte having improved permeability to the voids is used as a separator.

  The wetting index of the resin (base material) referred to in this specification is (mN / m) and is measured by a method in accordance with Japanese Industrial Standard (JIS) K-6768.

  Examples of the resin whose wetting index satisfies the above value include polyolefins such as polyethylene (PE), polypropylene (PP), and ethylene-propylene copolymer.

  For the porous film containing a resin having a wetness index satisfying the above value, a microporous film or a nonwoven fabric produced by various known production methods using the resin as a raw material can be used.

  Examples of the hydrophilic treatment of the porous membrane include a treatment in which a liquid (such as an aqueous solution) containing various known surfactants (nonionic surfactant) is applied to the porous membrane and dried; an ultraviolet treatment; Various known hydrophilization treatments such as corona discharge treatment;

  The thickness of the separator is preferably 30 to 400 μm.

  For the negative electrode according to the nonaqueous electrolyte battery of the present invention, a negative electrode active material containing a Li (lithium) -Al (aluminum) alloy is used.

  Examples of the negative electrode containing a Li—Al alloy as a negative electrode active material include a Li metal foil containing a Li—Al alloy. Li metal foil containing a Li-Al alloy is, for example, in a nonaqueous electrolyte battery assembled using a negative electrode having a laminate in which an Al metal foil is bonded to the surface of a Li metal foil. It is formed by alloying a part of Li related to the Li metal foil and Al related to the Al metal foil under the coexistence.

  Li is generally used for the negative electrode active material of the non-aqueous electrolyte battery, but as described above, since a relatively large amount of moisture is adsorbed to the hydrophilically treated separator, The amount of moisture taken into the inside increases. Since the negative electrode active material Li is deactivated by the presence of such moisture, battery characteristics are impaired when a hydrophilic separator is used.

  However, since the Li—Al alloy produced in the negative electrode in the battery as described above is pulverized, the specific surface area of the production surface of the Li—Al alloy in the negative electrode increases. Therefore, the amount of moisture in the battery is increased by using a separator that has been subjected to a hydrophilic treatment, and even if the negative electrode active material is partially deactivated by this moisture, sufficient active sites necessary for the discharge reaction of the battery remain. Therefore, it is possible to satisfactorily ensure the effect of improving heavy load discharge characteristics by using a nitrile solvent.

  The negative electrode is formed by, for example, forming an Li-Al alloy in the battery by attaching an Al metal foil to one side of the Li metal foil without using a current collector and assembling the battery using this. Can be manufactured.

  In addition, when using a current collector for the negative electrode, for example, a laminate in which an Al metal foil is pasted on one side of a Li metal foil is pasted on one or both sides of the current collector on the Li metal foil side. Can be manufactured by forming a Li-Al alloy in the battery.

  In the negative electrode, from the viewpoint of ensuring the above-mentioned effect better by sufficiently increasing the specific surface area of the Li-Al alloy formation site related to the negative electrode, the content of Al with respect to the total amount of Li and Al is: The amount is preferably 1 mol% or more, and more preferably 3 mol% or more. However, if the amount of Al in the negative electrode is too large, the capacity may decrease. Therefore, in the negative electrode, the content of Al with respect to the total amount of Li and Al is preferably 10 mol% or less, and more preferably 5 mol% or less.

  The thickness of the Li metal foil for constituting the negative electrode is preferably 0.1 to 0.3 mm, and the thickness of the Al metal foil is preferably 6 to 20 μm.

  In the case of using a current collector for the negative electrode, examples of the current collector include those made of copper, nickel, iron, and stainless steel. Examples of the current collector include plain woven wire mesh, expanded metal, and lath mesh. Punching metal, metal foam, foil (plate) and the like can be exemplified. The thickness of the current collector is preferably 0.005 to 0.1 mm, for example. It is also desirable to apply a paste-like conductive material such as carbon paste or silver paste to the surface of such a current collector.

  The positive electrode according to the non-aqueous electrolyte battery of the present invention includes, for example, a molded body in which a mixture (positive electrode mixture) containing a positive electrode active material, a conductive additive, a binder, and the like is formed into a pellet or the like, or the positive electrode mixture. A layer having a layer made of an agent (positive electrode mixture layer) on one side or both sides of a current collector can be used.

  Examples of the positive electrode active material related to the positive electrode mixture include manganese dioxide and graphite fluoride.

  Moreover, as a conductive support agent which concerns on a positive electrode mixture, for example, scaly graphite, acetylene black, ketjen black, carbon black etc. are mentioned, only 1 type may be used among these, and 2 or more types may be used. You may use together.

  Furthermore, examples of the binder related to the positive electrode mixture include fluororesins such as polyvinylidene fluoride, polytetrafluoroethylene, and a polymer of propylene hexafluoride, and only one of these may be used. Two or more kinds may be used in combination.

  In the case of a molded body of a positive electrode mixture, for example, the positive electrode can be manufactured by pressure-molding a positive electrode mixture prepared by mixing a positive electrode active material, a conductive additive and a binder into a predetermined shape. it can.

  In the case of a positive electrode having a positive electrode mixture layer and a current collector, for example, a positive electrode active material, a conductive aid, a binder, and the like are mixed with water or an organic solvent such as N-methyl-2-pyrrolidone (NMP). To prepare a positive electrode mixture-containing composition (slurry, paste, etc.) (the binder may be dissolved in a solvent), which is coated on a current collector and dried, and if necessary, a calendering treatment It can manufacture through the process of performing press processing, such as.

  However, a positive electrode is not limited to what was manufactured by said each method, The person manufactured by the other method may be sufficient.

  As a composition in the positive electrode mixture relating to the positive electrode, the amount of the positive electrode active material is preferably 80 to 90% by mass, the content of the conductive auxiliary agent is preferably 1.5 to 10% by mass, and the binder The content of is preferably 0.3 to 8% by mass.

  In the case of a molded body of a positive electrode mixture, the thickness is preferably 0.15 to 1 mm. On the other hand, in the case of a positive electrode having a positive electrode mixture layer and a current collector, the thickness of the positive electrode mixture layer (thickness per one side of the current collector) is preferably 30 to 150 μm.

  In the case where a current collector is used for the positive electrode, examples of the current collector include those made of stainless steel such as SUS316, SUS430, and SUS444. Examples of the current collector include plain weave wire mesh, expanded metal, lath. Examples thereof include a net, punching metal, metal foam, and foil (plate). The thickness of the current collector is preferably, for example, 0.05 to 0.2 mm. It is also desirable to apply a paste-like conductive material such as carbon paste or silver paste to the surface of such a current collector.

  In the nonaqueous electrolyte battery of the present invention, the negative electrode (negative electrode having a current collector) and the positive electrode (positive electrode having a current collector) are laminated with a separator (laminated electrode body) or A wound body (wound electrode body) obtained by winding the laminated body in a spiral shape, and a flat wound body (flat wound electrode body) obtained by forming the wound body so as to have a flat cross section. ) Can be used. In the case of a flat nonaqueous electrolyte battery, which will be described later, a positive electrode made of a positive electrode mixture and a negative electrode not having a current collector are accommodated in a flat battery case with a separator interposed therebetween. Can be used.

  The form of the non-aqueous electrolyte battery of the present invention is not particularly limited, and a battery case that seals the outer can and the sealing plate via a gasket or welds and seals the outer can and the sealing plate. Flat shape (including coin shape, button shape); Laminate shape having an exterior body made of a metal laminate film; Caulking and sealing between a bottomed cylindrical exterior can and a sealing plate via a gasket Any shape such as a cylindrical shape [cylindrical shape, rectangular shape (square cylindrical shape)] having a battery case for welding and sealing a plate can be used.

  In FIG. 1, the longitudinal cross-sectional view which represents typically an example of the nonaqueous electrolyte battery of this invention is shown. The non-aqueous electrolyte battery 1 shown in FIG. 1 is an example of a flat battery such as a coin type. In the non-aqueous electrolyte battery 1, the positive electrode 2 is accommodated inside an outer can 5 made of stainless steel or the like, and the negative electrode 3 is disposed thereon via a separator 4. The negative electrode 3 is pressure-bonded to the inner surface of the sealing plate 6. Further, a non-aqueous electrolyte (not shown) is injected into the battery 1.

  In the non-aqueous electrolyte battery 1, the outer can 5 also serves as a positive electrode terminal, and the sealing plate 6 also serves as a negative electrode terminal. The sealing plate 6 is fitted to the opening of the outer can 5 via a resin insulating gasket 7, and the opening end of the outer can 5 is tightened inward, whereby the insulating gasket 7 is By contacting the sealing plate 6, the opening of the outer can 5 is sealed, and the inside of the battery has a sealed structure. That is, the non-aqueous electrolyte battery 1 is formed of an outer can 5, a sealing plate 6, and an insulating gasket 7 interposed therebetween, and a positive electrode (for example, forming a positive electrode mixture) in a sealed battery case. The electrode body which laminated | stacked the positive electrode 2 which consists of a body, the separator 4, and the negative electrode 3, and the nonaqueous electrolyte solution are accommodated.

  In addition, when the negative electrode 3 contains a Li-Al alloy, as described above, the Li-Al alloy is a laminate in which an Al metal foil is bonded to a Li metal foil, and the Al metal foil side is the separator 4 side. In the battery case arranged in the above, Al in the Al metal foil and Li in the Li metal foil may be alloyed in the presence of the non-aqueous electrolyte.

  The nonaqueous electrolyte battery of the present invention can take the form of a primary battery or a form of a secondary battery, and has excellent heavy load continuous discharge characteristics. In addition to being suitable for applications such as power supplies for alarm devices, power supplies for communication devices, power supplies for small motors, etc., it should also be applied to the same applications as those for which conventionally known nonaqueous electrolyte batteries are used. Can do.

  Hereinafter, the present invention will be described in detail based on examples. However, the following examples do not limit the present invention.

Example 1
<Preparation of positive electrode>
295 mg of a positive electrode mixture prepared by mixing manganese dioxide as a positive electrode active material, carbon black as a conductive auxiliary agent, and polytetrafluoroethylene as a binder in a mass ratio of 93: 3: 4 is pressure-molded, It was set as the circular molded object (positive electrode) by planar view. This positive electrode had a thickness of 0.64 mm and a diameter of 16.0 mm.

<Production of negative electrode>
A Li metal foil having a thickness of 0.24 mm is punched into a circle having a diameter of 15.8 mm, and a circular Al metal foil having a diameter of 11 mm (thickness 6 μm) is pasted on one surface thereof to form a negative electrode (a negative electrode for battery assembly). Got. In this negative electrode, the content of Al in the total amount of Li and Al was 5% by mass.

<Hydrophilic treatment of separator>
A non-woven fabric made of PP having a thickness of 0.30 mm (PP wetting index of 32 mN / m) was coated with an aqueous solution of a polyethylene glycol-type nonionic surfactant having a concentration of 1% by mass, and dried to effect hydrophilic treatment. .

<Preparation of non-aqueous electrolyte>
A non-aqueous electrolyte was prepared by dissolving lithium perchlorate at a concentration of 0.5M in a mixed solvent of acetonitrile and EC in a volume ratio of 42:53, and further dissolving VC in an amount of 6% by mass. .

<Battery assembly>
Using the positive electrode, the negative electrode, the separator, and the non-aqueous electrolyte 128.4 mg, the non-aqueous electrolyte battery (diameter 20.0 mm, thickness 1.53 mm) having the structure shown in FIG. ) Was assembled.

Comparative Example 1
A non-aqueous electrolyte battery was produced in the same manner as in Example 1 except that the same PP nonwoven fabric used for the separator in Example 1 was used as the separator without being subjected to hydrophilic treatment.

Comparative Example 2
A nonaqueous electrolyte battery in the same manner as in Comparative Example 1 except that a Li metal foil having a thickness of 0.24 mm was punched into a circle having a diameter of 15.8 mm and used as a negative electrode for battery assembly without attaching an Al metal foil. Was made.

Comparative Example 3
Lithium perchlorate was dissolved at a concentration of 0.5M in a mixed solvent of acetonitrile and EC in a volume ratio of 18:77, and VC was further dissolved in an amount of 5% by mass to prepare a nonaqueous electrolyte.

  And, using the above non-aqueous electrolyte and punching a Li metal foil with a thickness of 0.24 mm into a circle with a diameter of 15.8 mm, and using it as a negative electrode for battery assembly without attaching an Al metal foil, A nonaqueous electrolyte battery was produced in the same manner as in Example 1.

Comparative Example 4
A nonaqueous electrolyte battery in the same manner as in Example 1, except that a Li metal foil having a thickness of 0.24 mm was punched into a circle having a diameter of 15.8 mm and used as a negative electrode for battery assembly without attaching an Al metal foil. Was made.

  The non-aqueous electrolyte batteries of Examples and Comparative Examples were subjected to the following heavy load discharge characteristic evaluation and high temperature storage characteristic evaluation.

<Heavy load discharge characteristics evaluation>
For each of the nonaqueous electrolyte batteries of Examples and Comparative Examples, the closed circuit voltage (CCV) 0.3 seconds after the start of discharge was measured under the condition of 100Ω.

<High temperature storage characteristics evaluation>
About the non-aqueous electrolyte battery of Example and Comparative Example (battery not subjected to other evaluation), it was stored in a constant temperature bath at 60 ° C. for 10 days, taken out and allowed to cool, and then a current value of 20 mA at 20 ° C. Then, continuous discharge was performed until the battery voltage reached 2.0 V, and the discharge capacity (capacity after storage) was determined.

  Table 1 shows the configurations of the nonaqueous electrolytic batteries of Examples and Comparative Examples, and Table 2 shows the evaluation results.

  The “non-aqueous electrolyte permeability” of the separator shown in Table 1 indicates that the same non-aqueous electrolyte solution used in each battery can penetrate well with respect to the same separator used in each battery. The result of evaluating whether or not, “○” means that the permeability of the non-aqueous electrolyte was good, “×” means that the non-aqueous electrolyte did not penetrate well doing.

  “−” In each evaluation result column shown in Table 2 means that each evaluation could not be performed because the non-aqueous electrolyte did not penetrate well into the separator.

  As shown in Table 1 and Table 2, a negative electrode containing a Li—Al alloy, a separator prepared by hydrophilizing a nonwoven fabric composed of a resin having a predetermined wetting index, and non-water containing a specific solvent The non-aqueous electrolyte battery of Example 1 using the electrolytic solution had a high voltage at the time of heavy load discharge characteristics evaluation, and had good heavy load discharge characteristics. In addition, the nonaqueous electrolyte battery of Example 1 had a large heavy load discharge capacity after high-temperature storage and excellent high-temperature storage characteristics.

  In contrast, the batteries of Comparative Examples 1 and 2 using a separator that had not been subjected to a hydrophilic treatment could not be evaluated because the non-aqueous electrolyte did not penetrate well into the separator. In addition, the battery of Comparative Example 3 that uses only Li for the negative electrode and does not contain a nitrile solvent, and the battery of Comparative Example 4 that uses only Li for the negative electrode are subjected to heavy load discharge characteristics evaluation. The voltage was low and the heavy load discharge characteristics were inferior.

DESCRIPTION OF SYMBOLS 1 Nonaqueous electrolyte battery 2 Positive electrode 3 Negative electrode 4 Separator 5 Exterior can 6 Sealing plate 7 Insulation gasket

Claims (8)

A non-aqueous electrolyte battery having a positive electrode, a negative electrode, a separator and a non-aqueous electrolyte,
The negative electrode contains a Li-Al alloy,
The separator is a porous film containing a resin having a wetting index of 30 to 45 mN / m, and has been hydrophilized.
The non-aqueous electrolyte contains, as an organic solvent, a nitrile solvent and a solvent (A) that is a solvent other than the nitrile solvent and has a surface tension of 25 to 45 mN / m ,
A non-aqueous electrolyte battery comprising mononitrile as the nitrile solvent .   The nonaqueous electrolyte battery according to claim 1, wherein the resin contained in the separator is a polyolefin.   The non-aqueous electrolyte battery according to claim 1, wherein the non-aqueous electrolyte contains a solvent having a dielectric constant of 30 to 110 as the solvent (A).   The non-aqueous electrolyte battery according to claim 1, wherein the non-aqueous electrolyte contains ethylene carbonate or propylene carbonate as the solvent (A). The nonaqueous electrolyte battery according to any one of claims 1 to 4 , wherein the content of the mononitrile is 20% by mass or more in the total amount of the organic solvent contained in the nonaqueous electrolyte. The secondary battery as mononitrile, acetonitrile, propionitrile, butyronitrile, valeronitrile, non-aqueous electrolyte battery according to any one of claims 1 to 5 containing a benzonitrile or acrylonitrile.   The nonaqueous electrolyte battery according to any one of claims 1 to 6, wherein in the negative electrode, the content of Al with respect to the total amount of Li and Al is 1 mol% or more.   The non-aqueous electrolyte battery according to claim 1, wherein the non-aqueous electrolyte contains vinylene carbonate.

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