JPWO2011070816A1 - Non-aqueous electrolyte secondary battery material and non-aqueous electrolyte secondary battery using the same - Google Patents

Abstract

The lithium ion battery 1 includes a lithium ion battery main body 2 having a positive electrode terminal 2A and a negative electrode terminal 2B protruding and having a safety valve as an opening means (not shown), and a casing 3 that accommodates the lithium ion battery main body 2. Become. The casing 3 is filled with an absorbent 4 that is a material for a non-aqueous electrolyte secondary battery. When an abnormality occurs in the operation of the lithium ion battery body 2, even if the lithium ion battery body 2 becomes hot, the safety valve is cleaved, and the electrolyte in the lithium ion battery body 2 is vaporized and ejected, Most of the vaporized electrolyte is quickly absorbed and fixed in the absorbent material 4. Thereby, discharge | release and leakage accompanying the gasification of the electrolyte solution at the time of high temperature by electrical abnormality, and the ejection of the electrolyte solution accompanying the internal pressure rise by the gas generated by electrolysis etc. can be prevented.

Description

  The present invention relates to a material for a non-aqueous electrolyte secondary battery such as a lithium ion battery used in electronic devices and automobiles, and a non-aqueous electrolyte secondary battery using this material, particularly at a high temperature due to an electrical abnormality. Nonaqueous electrolyte secondary battery material capable of preventing discharge and leakage associated with gasification of electrolyte, and injection of electrolyte due to increase in internal pressure due to gas generated by electrolysis, etc. and nonaqueous using this material The present invention relates to an electrolyte secondary battery.

  Lithium ion batteries, which are typical non-aqueous electrolyte secondary batteries, are scheduled to be used in hybrid cars and electric cars in the future, and their attention is increasing.

A typical configuration of this lithium-ion battery uses carbon as a negative electrode, a lithium transition metal oxide such as lithium cobaltate as a positive electrode, and lithium hexafluorophosphate (LiPF) as an electrolytic solution in an organic solvent such as ethylene carbonate or diethyl carbonate. ₆ ) A compound containing a lithium salt is used, but in general, each material of the negative electrode, the positive electrode, and the electrolyte only needs to move lithium ions and be chargeable / dischargeable by charge transfer. The embodiment can be adopted.

As the lithium salt, a LiPF ₆ or other fluorine-based complex salt such as LiBF ₄ or a salt such as LiN (SO ₂ Rf) ₂ .LiC (SO ₂ Rf) ₃ (Rf = CF ₃ or C ₂ F ₅ ) is used. In some cases.

  Usually, in order to give high conductivity and safety to the electrolyte, as the organic solvent, cyclic carbonate-based high dielectric constant / high boiling point solvents such as ethylene carbonate and propylene carbonate, dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate In some cases, a mixture of a low-viscosity solvent such as a lower chain carbonic acid ester or the like may be used, or a lower fatty acid ester may be used in part.

  However, in such a non-aqueous electrolyte secondary battery, when an electrical abnormality occurs, the battery becomes high temperature, and accordingly, the internal electrolyte is gasified to be discharged or leaked. In addition, when the battery is overcharged, the electrolytic solution is decomposed, but part of the decomposed electrolytic solution is gasified to increase the internal pressure in the battery. As a result, the battery swells or the safety valve opens. When the battery swells or the safety valve opens, the function of the battery is lost, and in that case, an internal electrolyte may be ejected (Patent Document 1).

  In order to prevent such an increase in internal pressure due to gas generation, various safety valves have been developed. For example, a structure as shown in Patent Document 2 has been proposed.

JP-A-9-199170 Japanese Patent Laid-Open No. 9-50799

  However, the techniques disclosed in Patent Document 1 and Patent Document 2 are both for discharging the electrolyte solution for the purpose of preventing an increase in internal pressure in the nonaqueous electrolyte secondary battery. There has been no effective means for quickly immobilizing and retaining the discharged electrolyte. When the discharged electrolyte solution adheres to the substrate or other electronic components, there is a problem that an electrical abnormality such as a short circuit or tracking is caused. Also, some electrolytes are flammable, and it is desirable that the electrolyte does not leak to the outside environment.

  In view of the above problems, the present invention provides a non-aqueous solution that prevents discharge and leakage associated with gasification of an electrolyte at a high temperature due to an electrical abnormality, or ejection of an electrolyte associated with an increase in internal pressure due to gas generated by electrolysis or the like. It aims at providing the material for electrolyte secondary batteries. Further, the present invention provides a non-aqueous electrolyte solution that prevents discharge and leakage associated with gasification of an electrolyte solution at a high temperature due to an electrical abnormality, or injection of an electrolyte solution associated with an increase in internal pressure due to gas generated by electrolysis or the like. An object is to provide a secondary battery.

  In order to solve the above problems, first, the present invention is disposed outside the opening means of a non-aqueous electrolyte secondary battery body provided with opening means for suppressing an increase in internal pressure due to gas generated by electrolysis or the like. A non-aqueous electrolyte secondary battery material comprising: an absorbent that forms a molecular compound with the electrolyte solution of the non-aqueous electrolyte secondary battery. Provided (Invention 1)

  According to the above invention (Invention 1), by disposing an absorbent that forms an electrolyte solution and a molecular compound outside the opening means of the nonaqueous electrolyte secondary battery body, the electrolyte solution at a high temperature due to an electrical abnormality can be obtained. Immediately immobilize the electrolyte leaked from the non-aqueous electrolyte secondary battery body due to discharge and leakage associated with gasification and the ejection of electrolyte from the opening means due to the increase in internal pressure due to gas generated by electrolysis etc. It is possible to effectively suppress the release of the electrolytic solution to the external environment and hold it in a stable state.

  In the said invention (invention 1), it is preferable that the said absorber is an organic type, an inorganic type, or an organic-inorganic composite material (invention 2).

  Secondly, the present invention provides a nonaqueous electrolyte secondary battery body outside the opening means of a nonaqueous electrolyte secondary battery body provided with an opening means for suppressing an increase in internal pressure due to gas generated by electrolysis or the like. A non-aqueous electrolyte secondary battery comprising an absorbent material that absorbs the electrolyte solution is provided (Invention 3).

  According to the above invention (Invention 3), by disposing the electrolyte absorbing material outside the opening means of the non-aqueous electrolyte secondary battery body, the discharge accompanying the gasification of the electrolyte at a high temperature due to an electrical abnormality In addition, it is possible to fix the electrolyte leaked from the non-aqueous electrolyte secondary battery body due to the leakage or the injection of electrolyte from the opening means due to the increase in internal pressure due to gas generated by electrolysis, etc., to the external environment The release of the electrolyte can be effectively suppressed.

  In the said invention (invention 3), it is preferable that the said absorber is arrange | positioned in the casing provided in the outer side of the said open | release means (invention 4).

  According to the said invention (invention 4), the outflow to an external environment can further be reduced by containing the discharge | released electrolyte solution in a casing.

  In the said invention (invention 3 and 4), it is preferable that the said absorber forms a molecular compound with the said electrolyte solution (invention 5).

  According to the said invention (invention 5), since the reaction in which the electrolytic solution forms the molecular compound is rapid, it is possible to quickly fix the electrolytic solution and suitably suppress the release to the external environment.

  In the said invention (invention 3-5), it is preferable that the said absorber is an organic type, an inorganic type, or an organic-inorganic composite type | system | group material (invention 6).

  According to the non-aqueous electrolyte secondary battery of the present invention, the absorbent that absorbs the electrolyte is disposed outside the safety valve that prevents the increase in internal pressure due to the gas generated by high temperature, electrolysis or the like. Even if released, it can be quickly absorbed and retained by the absorbent material, and the outflow to the external environment can be greatly reduced. Such a non-aqueous electrolyte secondary battery of the present invention can be suitably used for various electric devices and electronic devices without polluting the circuit board.

It is the schematic which shows the nonaqueous electrolyte secondary battery which concerns on one Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  First, the material for a non-aqueous electrolyte secondary battery will be described. The material for a non-aqueous electrolyte secondary battery in the present embodiment is composed of an absorbent material that forms a molecular compound with the electrolyte of the non-aqueous electrolyte secondary battery. Here, with a molecular compound, two or more kinds of compounds that can exist stably alone are bonded by a relatively weak interaction other than a covalent bond, such as a hydrogen bond or van der Waals force. Compounds, including hydrates, solvates, addition compounds, inclusion compounds, and the like. Such a molecular compound can be formed by a contact reaction between a compound that forms the molecular compound and an electrolytic solution, and the electrolytic solution can be changed to a solid compound.

  Examples of the molecular compound described above include an inclusion compound formed by inclusion of an electrolytic solution with a host compound by a contact reaction between the host compound and the electrolytic solution.

  Among the molecular compounds, the host compound that forms the clathrate compound that clathrates the electrolyte is known to be composed of an organic compound, an inorganic compound, and an organic / inorganic composite compound. Systems, multimolecular systems, polymer hosts and the like are known.

  Examples of the monomolecular host include cyclodextrins, crown ethers, cryptands, cyclophanes, azacyclophanes, calixarenes, cyclotriveratrylenes, spherands, and cyclic oligopeptides.

  Multimolecular hosts include ureas, thioureas, deoxycholic acids, cholic acids, perhydrotriphenylenes, tri-o-thymotides, bianthrils, spirobifluorenes, cyclophosphazenes, mono Alcohols, diols, hydroxybenzophenones, acetylene alcohols, phenols, bisphenols, trisphenols, tetrakisphenols, polyphenols, naphthols, bisnaphthols, diphenylmethanols, carboxylic acid amides, thioamides, Examples include bixanthenes, carboxylic acids, imidazoles, hydroquinones, and organic ammonium salts.

  Furthermore, as a polymer host, chitins, chitosans, polyethylene glycol arm type polymers having 1,1,2,2-tetrakisphenylethane as a core, α, α, α ′, α′-tetrakisphenylxylene And polyethylene glycol arm-type polymers having a core.

  In addition, organophosphorus compounds, organosilicon compounds, and the like can also be used.

  Inorganic host compounds include titanium oxide, graphite, alumina, transition metal dicargogenite, lanthanum fluoride, clay mineral (montmorillonite, etc.), silver salt, silicate, phosphate, zeolite, magnesium oxide, silica, porous glass In particular, inorganic porous materials that are porous are effective, such as silica, calcium silicate, magnesium aluminate metasilicate, alumina, zeolite, magnesium oxide, magnesium silicate, aluminum silicate, etc. The porous material is preferable.

  Furthermore, some organometallic compounds exhibit properties as host compounds. For example, organoaluminum compounds, organotitanium compounds, organoboron compounds, organozinc compounds, organoindium compounds, organogallium compounds, organotellurium compounds, organotins. Examples thereof include compounds, organic zirconium compounds, and organic magnesium compounds. Further, it is possible to use a metal salt of an organic carboxylic acid, an organic metal complex, or the like, but it is not particularly limited as long as it is an organic metal compound.

  These host compounds may be used alone as an absorbent material, or may be used in combination of two or more, and are not particularly limited as long as they can absorb an electrolytic solution. Materials and inorganic porous materials are particularly effective.

  Specifically, as the solvent of the electrolytic solution, cyclic carbonate high dielectric constant / high boiling point solvent such as ethylene carbonate / propylene carbonate, low viscosity solvent dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, etc. In some cases, lower chain carbonates are used and some lower fatty acid esters are used.

  Therefore, it is preferable to use a variety of absorbent materials in which one absorbent material can enclose a plurality of solvents, as an absorbent material as a non-aqueous electrolyte secondary battery material. The material is particularly effective.

  For example, cyclodextrins such as α-cyclodextrin and β-cyclodextrin, calixarenes, urea, deoxycholic acid, cholic acid, 1,1,6,6-tetraphenylhexa-2,4-diyne-1, Acetylene alcohols such as 6-diol, bisphenols such as 1,1-bis (4-hydroxyphenyl) cyclohexane, tetrakisphenols such as 1,1,2,2-tetrakis (4-hydroxyphenyl) ethane, bis- naphthols such as β-naphthol, carboxylic acid amides such as diphenic acid bis (dicyclohexylamide), hydroquinones such as 2,5-di-t-butylhydroquinone, chitin, chitosan, silica, calcium silicate, and metasilicate aluminum Magnesium oxide, alumina, zeolite, magnesium oxide, Magnesium, aluminum silicate, organic metal compounds and the like.

  Next, a non-aqueous electrolyte secondary battery using the non-aqueous electrolyte secondary battery material as described above will be described.

  FIG. 1 is a schematic view showing a lithium ion battery as a nonaqueous electrolyte secondary battery according to this embodiment. In FIG. 1, a lithium ion battery 1 accommodates a lithium ion battery main body 2 having a positive electrode terminal 2A and a negative electrode terminal 2B projecting and having a safety valve (not shown) as an opening means, and the lithium ion battery main body 2. A non-aqueous electrolyte secondary battery material inside the casing 3, that is, outside the safety valve of the lithium ion battery main body 2. The absorbent material 4 is filled. Moreover, the casing 3 is sealed with the sealing material 5, and the positive electrode terminal 2A and the negative electrode terminal 2B are electrically connected to the connection electrode terminal 6A and the connection electrode terminal 6B, respectively. In addition, the lithium ion battery main body 2 in this embodiment exhibits the function to supply electric power, and is normally used alone as a lithium ion battery.

  The operation of the above configuration will be described. By connecting the connection electrode terminal 6A and the connection electrode terminal 6B of the lithium ion battery 1 to various electric devices and the like, power is supplied from the lithium ion battery main body 2. At this time, when an abnormality occurs in the operation of the lithium ion battery main body 2, the lithium ion battery main body 2 becomes high temperature, and the internal pressure of the lithium ion battery main body 2 increases accordingly. When a predetermined internal pressure is exceeded, the safety valve is opened, the internal pressure of the lithium ion battery main body 2 is released, and the electrolytic solution vaporized in the lithium ion battery main body 2 is ejected. At this time, most of the evaporated electrolytic solution is quickly absorbed and fixed in the absorbent material 4.

  Thereby, leakage of the electrolyte from the lithium ion battery 1 can be prevented. In particular, in the present embodiment, the lithium ion battery main body 2 that normally functions as a lithium ion battery alone is disposed in the casing 3, so that the discharged electrolyte solution is sealed in the casing 3 to the external environment. Can be further reduced.

  Although the present invention has been described above with reference to the accompanying drawings, the present invention is not limited to the above-described embodiment, and various modifications can be made. For example, the structure of the casing 3 can be variously formed if the absorbent material 4 is disposed outside the safety valve.

  EXAMPLES Hereinafter, although an Example etc. demonstrate this invention further in detail, this invention is not limited to the following Example etc. at all.

[Example 1]
In a 50 mL beaker, 0.2 g of propylene carbonate as an electrolytic solution and 1 g of 1,1-bis (4-hydroxyphenyl) cyclohexane (host compound 1) were put in contact as they were, and left for 10 minutes. As a result of measuring physical properties of the obtained substance, an inclusion compound in which the host compound 1 and propylene carbonate were 1: 1 (molar ratio) was obtained.

[Example 2]
In a 50 mL beaker, 0.2 g of propylene carbonate and 1 g of 1,1,2,2-tetrakis (4-hydroxyphenyl) ethane (host compound 2) were contacted as they were as an electrolyte, and left for 10 minutes. As a result of measuring physical properties of the obtained substance, an inclusion compound in which the host compound 2 and propylene carbonate were 1: 4 (molar ratio) was obtained.

Example 3
In a 50 mL beaker, 0.2 g of propylene carbonate and 1 g of β-cyclodextrin (host compound 3) were brought into contact as electrolytes and allowed to stand for 10 minutes. As a result of measuring physical properties of the obtained substance, an inclusion compound in which the host compound 3 and propylene carbonate were 1: 1 (molar ratio) was obtained.

Example 4
In a 50 mL beaker, 0.2 g of propylene carbonate and 1 g of bis-β-naphthol (host compound 4) were brought into contact as electrolytes and allowed to stand for 10 minutes. As a result of measuring the physical properties of the obtained substance, an inclusion compound in which the host compound 4 and propylene carbonate were 1: 1 (molar ratio) was obtained.

Example 5
In the prototype lithium ion secondary battery shown in FIG. 1 described above, 0.5 g of the aforementioned 1,1-bis (4-hydroxyphenyl) cyclohexane (host compound 1) is contained outside the safety valve, and an electrolyte containing propylene carbonate A repetitive test of charging / discharging of a lithium ion battery using the battery was performed. After the test, the lithium ion battery was disassembled and the physical properties of the host compound 1 were measured. As a result, it was confirmed that the host compound 1 included propylene carbonate.

  Thereby, it turned out that the electrolyte solution discharge | released from a lithium ion battery can be fix | immobilized by the host compound 1. FIG.

Example 6
In Example 5, the results of examination in the same manner except that 0.5 g of 1,1,2,2-tetrakis (4-hydroxyphenyl) ethane (host compound 2) was incorporated instead of the host compound 1. It was confirmed that the host compound 2 included propylene carbonate.

  Thus, it was found that the electrolyte released from the lithium ion battery can be immobilized by the host compound 2.

Example 7
In Example 5, examination was conducted in the same manner except that 0.5 g of β-cyclodextrin (host compound 3) was included instead of the host compound 1, and as a result, the host compound 3 included propylene carbonate. It was confirmed.

  Thus, it was found that the electrolyte released from the lithium ion battery can be immobilized by the host compound 3.

Example 8
In Example 53, examination was conducted in the same manner except that 0.5 g of bis-β-naphthol (host compound 4) was included instead of host compound 1, and as a result, host compound 4 contained propylene carbonate. It was confirmed that

  Thus, it was found that the electrolyte released from the lithium ion battery can be immobilized by the host compound 4.

Example 9
In Example 5, examination was conducted in the same manner except that 0.5 g of porous silica was contained as a host compound instead of the host compound 1. As a result, it was confirmed that the porous silica contained propylene carbonate. It was.

  Thereby, it turned out that the electrolyte solution discharge | released from a lithium ion battery can be fix | immobilized by porous silica.

Example 10
In Example 5, examination was conducted in the same manner except that 0.5 g of porous magnesium metasilicate aluminate was incorporated as a host compound instead of the host compound 1. As a result, porous magnesium aluminate metasilicate was propylene carbonate. It was confirmed that it contains.

  Thereby, it turned out that the electrolyte solution discharge | released from a lithium ion battery can be fix | immobilized by porous magnesium aluminate metasilicate.

Example 11
In Example 5, examination was conducted in the same manner except that 0.5 g of porous alumina was present as the host compound instead of the host compound 1. As a result, it was confirmed that the porous alumina contained propylene carbonate. It was.

  Thereby, it turned out that the electrolyte solution discharge | released from a lithium ion battery can be fix | immobilized by porous alumina.

Example 12
In Example 5, examination was conducted in the same manner except that 0.5 g of porous magnesium oxide was contained as a host compound instead of the host compound 1, and as a result, the porous magnesium oxide contained propylene carbonate. Was confirmed.

  Thereby, it turned out that the electrolyte solution discharge | released from a lithium ion battery can be fix | immobilized by porous magnesium oxide.

1 ... Lithium ion battery (non-aqueous electrolyte secondary battery)
2. Lithium ion battery body (non-aqueous electrolyte secondary battery body)
3 ... Casing 4 ... Absorbing material (material for non-aqueous electrolyte secondary battery)

Claims (6)

  A material for a non-aqueous electrolyte secondary battery disposed outside the opening means of a non-aqueous electrolyte secondary battery body provided with an opening means for suppressing an increase in internal pressure due to gas generated by electrolysis or the like, A material for a non-aqueous electrolyte secondary battery, comprising an absorbent that forms a molecular compound with the electrolyte solution of the non-aqueous electrolyte secondary battery.   The material for a non-aqueous electrolyte secondary battery according to claim 1, wherein the absorbent is an organic, inorganic, or organic / inorganic composite material.   An absorbing material that absorbs the electrolytic solution is disposed outside the opening means of the non-aqueous electrolyte secondary battery body that includes an opening means that suppresses an increase in internal pressure due to gas generated by electrolysis or the like. Non-aqueous electrolyte secondary battery.   The non-aqueous electrolyte secondary battery according to claim 3, wherein the absorbent material is disposed in a casing provided outside the opening means.   The non-aqueous electrolyte secondary battery according to claim 3 or 4, wherein the absorbent material forms a molecular compound with the electrolytic solution.   The non-aqueous electrolyte secondary battery according to claim 3, wherein the absorbent material is an organic material, an inorganic material, or an organic / inorganic composite material.

Images