JP4340984B2 - Non-aqueous electrolyte secondary battery - Google Patents

Description

  The present invention relates to a non-aqueous electrolyte secondary battery having high voltage, high capacity, and excellent charge / discharge cycle characteristics.

A non-aqueous electrolyte secondary battery using lithium (lithium secondary battery) is a positive and negative electrode containing a material capable of reversibly occluding and releasing lithium, a non-aqueous electrolyte containing a lithium salt, and appropriately holding these, Consists of isolation members. Since lithium is light and has a very low potential, secondary batteries using lithium or lithium alloy as a negative electrode have excellent characteristics of high voltage and high capacity, but also have the disadvantage of dendrite depositing and being easily short-circuited. It was. Batteries having a carbon material in the negative electrode are far from the high capacity of batteries using lithium metal as the negative electrode, although an improvement in cycle characteristics is observed in that the degree of decrease in capacity is small when charging and discharging are repeated over a long period of time. . On the other hand, when an amorphous oxide or a chalcogen compound is used for the negative electrode material, the amount of lithium occluded dramatically increases, and an excellent secondary battery having an extremely high capacity can be obtained. However, this battery has a problem in that the capacity decreases when charging and discharging are repeated over a long period of time. Attempts to improve charge / discharge characteristics (cycle characteristics) upon repeated charge / discharge over a long period of time have been studied from various viewpoints. Many attempts to improve cycle characteristics by adding a specific compound to the electrolytic solution have been studied. For example, Patent Document 1, Patent Document 2, and Patent Document 3 include adding amines, and Patent Document 4 includes lithium. Although it has been described that a compound having a coordinating group with respect to is added, the effect of improving the cycleability is not sufficient, and further improvement has been desired.
JP-A-6-84523 JP-A-6-84524 JP-A-6-333595 JP-A-5-234618

  An object of the present invention is to improve the cycle performance of a lithium secondary battery, and in particular, to improve the cycle performance of a lithium secondary battery using an amorphous oxide or a chalcogen compound as a negative electrode material. .

An object of the present invention is a method of manufacturing a non-aqueous electrolyte of a lithium secondary battery comprising a compound to prevent oxidative degradation and mixed solvents and the supporting salt, acyclic shaped so that the liquid temperature did not exceed 30 ° C. Following the mixed solvent preparation step of preparing the mixed solvent by adding ethylene carbonate as the cyclic carbonate to any one or more selected from diethyl carbonate, dimethyl carbonate, and methyl ethyl carbonate as the carbonate , LiBF ₄ and / or LiPF ₆ which is a lithium salt as the supporting salt in the mixed solvent is set to a concentration of 0.2 to 3 mol with respect to 1 liter of the non-aqueous electrolyte so that the liquid temperature does not exceed 30 ° C. a supporting salt added step of adding small portions, followed by the supporting salt addition step, a compound of the following general formula (1) as the compound prior to A step of dissolving in added in an amount of 1g or more 50g less in the nonaqueous electrolyte solution 1 kg, was achieved by the method for producing a non-aqueous electrolyte for a lithium secondary battery, which comprises a.

In the general formula (1), R ₁₁ is a substituted or unsubstituted aryl group having 6 to 24 carbon atoms in total , and R ₁₂ and R ₁₃ are substituted or unsubstituted carbon atoms having 1 to 24 carbon atoms that are electron donating groups. Represents an alkyl group. R ₁₁ , R ₁₂ and R ₁₃ may combine with each other to form a ring.

According to the method for producing a non-aqueous electrolyte for a secondary battery of the present invention, a non-aqueous electrolyte secondary battery having a high capacity and little reduction in discharge capacity due to repeated charge and discharge can be obtained.

  Although the preferable aspect of this invention is hung up below, this invention is not limited to these. 1) A nonaqueous electrolyte secondary battery comprising a nonaqueous electrolyte solution containing a positive electrode, a negative electrode, and a lithium salt, wherein the compound contains a compound represented by the following general formula (1): Achieved by secondary battery.

In the general formula (1), R ₁₁ represents an aryl group, and R ₁₂ and R ₁₃ represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aralkyl group, an aryl group, or a heterocyclic residue. R ₁₁ , R ₁₂ and R ₁₃ may be bonded to each other to form a ring.
2) The nonaqueous electrolyte secondary battery according to item 1, wherein the compound represented by the general formula (1) is a compound represented by the following general formula (2) or (3).

In the general formulas (2) and (3), R ₂₁ is a divalent to hexavalent residue obtained by removing any 2 to 6 hydrogen atoms from an aromatic hydrocarbon, and R ₃₁ and R ₃₂ are the general formula (1) for R ₁₁ in the above _{formula, R 22, R 23, R} 33 and R ₃₄ has the same meaning as R ₁₂ in general formula (1). n represents an integer of 2 to 6 corresponding to the valence of R ₂₁ . R ₂₂ and R ₂₃ may combine with each other to form a ring. Further, two CH (R ₂₂ ) R ₂₃ substituting R ₂₁ may be bonded to each other to form a ring. R ₃₁ , R ₃₂ , R ₃₃ and R ₃₄ may combine with each other to form a ring. R ₃₁ and R ₃₂ may be condensed to form a polynuclear aromatic ring.
3) The nonaqueous electrolyte secondary battery according to Item 1, wherein the compound represented by the general formula (1) is contained in the electrolyte.
4) The amount of the compound represented by the general formula (1) contained in the electrolytic solution is 1 g or more and 50 g or less per kg of the electrolytic solution. battery.
5) From the paragraph 1, wherein the negative electrode is a negative electrode mainly containing an amorphous chalcogen compound or oxide containing three or more kinds of atoms selected from periodic table 1, 2, 13, 14, and 15 group atoms. The nonaqueous electrolyte secondary battery according to any one of 4.
6) The nonaqueous electrolyte secondary battery according to item 5, wherein the negative electrode contains a compound represented by the general formula (4).
General formula (4) SnM ³ _p M ⁵ _q M ⁷ _r
In the formula, M ³ is at least one element selected from Si, Ge, Pb, P, B, and Al, and M ⁵ is at least selected from Li, Na, K, Rb, Cs, Mg, Ca, Sr, and Ba. M ⁷ represents at least one element selected from O and S. p and q each represent a numerical value of 0.1 or more and 2 or less, and r represents a numerical value of 1 or more and 6 or less.
7) The nonaqueous electrolyte secondary battery according to item 6, wherein M ⁷ in the general formula (4) according to item 6 is oxygen.

  When a lithium secondary battery is charged, the potential of the positive electrode is increased by releasing lithium ions and electrons, and the potential of the negative electrode is decreased by storing lithium ions and electrons, and electric energy is stored. At the time of discharge, electric energy is released by the reverse reaction. Ideally, the series of electrochemical reactions should be reversible, but in reality, irreversible chemical changes inside the battery are unavoidable due to repeated charge and discharge, and therefore battery performance deteriorates, such as capacity reduction. The main reason for the deterioration of the battery performance is that the electrolyte solvent is oxidatively decomposed on the positive electrode, and the decomposed product is gradually deposited on the positive electrode to inhibit a desirable electrochemical reaction inside the battery. I guessed to do it. This is because a positive electrode containing a lithium-containing transition metal oxide as an active material becomes oxidative with increasing potential and is likely to generate a strong oxidant such as active oxygen. As a result of adding various compounds for the purpose of preventing oxidative decomposition of the electrolyte solvent and examining the effects thereof, the present inventors have found that the compound of the general formula (1) is extremely effective, and have made the present invention.

Hereinafter, the compound of the general formula (1) will be described in detail. In the general formula (1), R ₁₁ represents a substituted or unsubstituted aryl group having 6 to 24 carbon atoms (for example, a phenyl group, a naphthyl group, an anthryl group, etc.). R ₁₂ and R ₁₃ are a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 24 carbon atoms (such as a methyl group, an ethyl group, a butyl group, a dodecyl group, a cyclohexyl group), a substituted or unsubstituted carbon group having 2 to 24 carbon atoms, Unsubstituted alkenyl group (vinyl group, allyl group, 1-decene-10-yl group, cyclopentadienyl group, etc.), substituted or unsubstituted alkynyl group having 2 to 24 carbon atoms (ethynyl group, propargyl group, 1-ethynylcyclohexyl group, etc.), substituted or unsubstituted aralkyl group having 7 to 24 carbon atoms (benzyl group, diphenylmethyl group, naphthylmethyl group, etc.), substituted or unsubstituted aryl group having 6 to 24 carbon atoms in total (Phenyl group, naphthyl group, anthryl group, etc.) or a substituted or unsubstituted heterocyclic residue having 3 to 24 carbon atoms (pyridyl group, Noryl group, an imidazolyl group, indazolyl group, furyl group, thienyl group, thiadiazolyl group, benzoxazolyl group, benzothiazolyl group, benzimidazolyl group, a 2-like thiazolinyl). Of these, an alkyl group, an alkenyl group, an aralkyl group, and an aryl group are preferable.

The substituent is not particularly limited, but an electron donating group is preferable. An electron donating group refers to a group having a Hammett sigma value of less than zero. Hammett's sigma value is widely recognized in organic chemistry, and many references are known, for example, Naoki Inamoto's “Hammett's Law” (Maruzen). Among the electron donating groups, an alkyl group is particularly preferable. R ₁₁ , R ₁₂ and R ₁₃ may combine with each other to form a ring.

  Among the compounds represented by the general formula (1), particularly preferred compounds are represented by the following general formula (2) or (3).

In the general formulas (2) and (3), R ₂₁ represents a divalent to hexavalent residue obtained by removing any 2 to 6 hydrogen atoms from an aromatic hydrocarbon (for example, benzene, naphthalene, anthracene, phenanthrene, etc.). To express. Of these, divalent to tetravalent residues derived from benzene and naphthalene are preferred. R ₃₁ and R ₃₂ are the same as R _{11 in the} general formula (1), and a phenyl group is preferable. R ₂₂ , R ₂₃ , R ₃₃ and R ₃₄ have the same meaning as R _{12 in the} general formula (1). n represents an integer of 2 to 6 corresponding to the valence of R ₂₁ . R ₂₂ and R ₂₃ may combine with each other to form a ring. Further, two CH (R ₂₂ ) R ₂₃ substituting R ₂₁ may be bonded to each other to form a ring. R ₃₁ , R ₃₂ , R ₃₃ and R ₃₄ may combine with each other to form a ring. R ₃₁ and R ₃₂ may be condensed to form a polynuclear aromatic ring (for example, naphthalene ring).

  The reason why the compound of the general formula (1) has improved cycleability is not speculated, but considering that the hydrogen atom on the carbon adjacent to the aryl group is easily extracted as a radical, It seems that the compound of the general formula (1) preferentially reacts with active oxygen generated at the positive electrode to prevent decomposition of the electrolyte solvent.

  Next, although the specific example of a compound represented by General formula (1) is shown, this invention is not limited to these.

  Most of the compounds represented by the general formula (1) are available as reagents. Representative reagent manufacturers or agents include Wako Pure Chemical Industries, Ltd., Tokyo Chemical Industry Co., Ltd., Sigma-Aldrich Japan Co., Ltd. and the like.

  Next, the addition method and addition amount of the compound represented by the general formula (1) will be described. The compound represented by the general formula (1) may be added to any of the positive electrode, the negative electrode, and the electrolyte, but is preferably added to the electrolytic solution in view of the presumed mechanism of action. The addition amount can be arbitrarily selected, but a typical value is 1 g to 50 g per kg of the electrolyte. Preferably, it is 5 to 20 g in 1 kg of the electrolyte.

  Hereinafter, the manufacturing method of the nonaqueous electrolyte secondary battery of the present invention will be described. In the nonaqueous electrolyte secondary battery of the present invention, a positive and negative electrode sheet wound with a separator (winding group) is inserted into a battery can, the can and the electrode are electrically connected, and the electrolyte is injected. Create after sealing. Moreover, various members (a sealing plate, a lead plate, a gasket, an exterior material, etc.) are used as needed.

The positive (negative) electrode sheet can be prepared by applying a positive (negative) electrode mixture onto a current collector, drying, and compressing. The mixture is prepared by mixing a positive electrode (or negative electrode) material and a conductive agent, kneading and mixing a binder (suspension or emulsion of resin powder) and a dispersion medium, followed by a mixer, It can be carried out by dispersing with a stirring mixer or disperser such as a homogenizer, dissolver, planetary mixer, paint shaker or sand mill. As the dispersion medium, water or an organic solvent is used, but water is preferable. In addition, additives such as a dispersant, a filler, an ionic conductive agent, and a pressure enhancer may be added as appropriate. Application can be performed by various methods, for example, reverse roll method, direct roll method, blade method, knife method, extrusion method, curtain method, gravure method, bar method, dipping method and squeeze method. I can do it. A blade method, a knife method and an extrusion method are preferred. The application is preferably performed at a speed of 0.1 to 100 m / min. Under the present circumstances, the surface state of a favorable coating layer can be obtained by selecting the said application | coating method according to the liquid physical property of a mixture paste, and drying property. The thickness, length and width of the coating layer are determined by the size of the battery. The thickness of a typical coating layer is 10 to 1000 μm in a compressed state after drying. The electrode sheet after application is dried and dehydrated by the action of hot air, vacuum, infrared rays, far infrared rays, electron beams and low-humidity air. These methods can be used alone or in combination. The drying temperature is preferably in the range of 80 to 350 ° C, particularly preferably in the range of 100 to 250 ° C. The content after drying is preferably 2000 ppm or less, and more preferably 500 ppm or less. For the compression of the electrode sheet, a generally employed pressing method can be used, and a die pressing method and a calendar pressing method are particularly preferable. The press pressure is not particularly limited, but is preferably 10 kg / cm ^{2 to 3} t / cm ² . The press speed of the calendar press method is preferably 0.1 to 50 m / min. The pressing temperature is preferably room temperature to 200 ° C.

The positive electrode material used in the present invention is a lithium-containing transition metal oxide. Preferably, it is an oxide mainly containing lithium and at least one transition metal element selected from Ti, V, Cr, Mn, Fe, Co, Ni, Mo and W, and the molar ratio of lithium to transition metal is 0. .3 to 2.2 compounds. More preferably, it is an oxide mainly containing lithium and at least one transition metal element selected from V, Cr, Mn, Fe, Co, and Ni, and the molar ratio of lithium to transition metal is 0.3 to 2 .2 compound. In addition, Al, Ga, In, Ge, Sn, Pb, Sb, Bi, Si, P, B, or the like may be contained within a range of less than 30 mole percent with respect to the transition metal present mainly. Further preferred lithium-containing transition metal oxides are Li _x CoO ₂ , Li _x NiO ₂ , Li _x MnO ₂ , Li _x Co _a Ni _1-a O ₂ , Li _x Co _b V _1-b O _z , Li _x Co. _b Fe _1-b O ₂ , Li _x Mn ₂ O ₄ , Li _x Mn _c Co _{2 —C} O ₄ , Li _x Mn _c Ni _{2 —c} O ₄ , Li _x Mn _c V _{2 —c} O ₄ , Li _{x Mn c Fe 2-c O 4} ( wherein x = 0.7~1.2, a = 0.1~0.9, b = 0.8~0.98, c = 1.6~1.96 Z = 2.01-2.3). The most preferred lithium-containing transition metal _{oxides, Li x CoO 2, Li x} NiO 2, Li x MnO 2, Li x Co a Ni 1-a O 2, Li x Mn 2 O 4, Li x Co b V 1 _-b O _z (x = 0.7 to 1.2, a = 0.1 to 0.9, b = 0.9 to 0.98, z = 2.01 to 2.3). In addition, the value of x is a value before the start of charging / discharging, and increases / decreases by charging / discharging.

  The negative electrode material of the present invention is mainly an amorphous chalcogen compound or oxide containing three or more atoms selected from Group 1, 2, 13, 14, and 15 atoms of the periodic table. The term “amorphous” as used herein refers to an X-ray diffraction method using CuKα rays that has a broad scattering band having a peak at a 2θ value of 20 ° to 40 °, and has a crystalline diffraction line. Good. Preferably, the strongest intensity of the crystalline diffraction lines seen at 2θ values of 40 ° or more and 70 ° or less is 500 of diffraction line intensities at the apexes of broad scattering bands seen at 2θ values of 20 ° or more and 40 ° or less. It is preferably not more than twice, more preferably not more than 100 times, particularly preferably not more than 5 times, and most preferably not having a crystalline diffraction line.

A preferable negative electrode material used in the present invention is represented by the following general formula (0).
General formula (0) M ¹ M ² _p M ⁴ _q M ⁶ _r
In the formula, M ¹ and M ² are at least one selected from Si, Ge, Sn, Pb, P, B, Al, and Sb, preferably Si, Ge, Sn, P, B, and Al, Particularly preferred are Si, Sn, P, B, and Al. M ⁴ is at least one selected from Li, Na, K, Rb, Cs, Mg, Ca, Sr, and Ba, preferably K, Cs, Mg, and Ca, and particularly preferably Cs and Mg. M ⁶ is at least one selected from O, S, and Te, preferably O and S, and particularly preferably O. p and q are each 0.001-10, Preferably it is 0.01-5, Most preferably, it is 0.1-2. r is 1-50, Preferably it is 1-26, Most preferably, it is 1-6. The valences of M ¹ and M ² are not particularly limited, and may be a single valence or a mixture of valences. The M ^1, M ^2, the ratio of M ⁴ can be continuously changed in a range M ² and M ⁴ are from 0.001 to 10 molar equivalents relative to M ^1, the amount of M ⁶ accordingly (typically The value of r in equation (3) also changes continuously.

Among the compounds listed above, amorphous oxides or sulfides mainly composed of Sn represented by the following general formula (4) are preferable.
General formula (4) SnM ³ _p M ⁵ _q M ⁷ _r
In the formula, M ³ is at least one selected from Si, Ge, Pb, P, B and Al, preferably Si, Ge, P, B and Al, particularly preferably Si, P, B and Al. is there. M ⁵ is at least one selected from Li, Na, K, Rb, Cs, Mg, Ca, Sr, and Ba, preferably Cs and Mg, and particularly preferably Mg. M ⁷ is at least one selected from O and S, and O is preferable. p and q are each 0.01-5, Preferably it is 0.1-2. r is 1-20, Preferably it is 1-6. As a matter of course, a combination of preferable ones in each condition is most preferable.

In the present invention, particularly excellent effects can be obtained with a compound in which the valence of Sn is bivalent. The valence of Sn can be determined by a chemical titration operation. For example, it can be analyzed by the method described on page 165 of Physics and Chemistry of Glasses Vol. 8 No. 4 (1967). It can also be determined from a night shift by Sn solid nuclear magnetic resonance (NMR) measurement. For example, in wide measurement, metal Sn (zero-valent Sn) has an extremely low magnetic field peak around 7000 ppm with respect to Sn (CH ₃ ) ₄ , whereas SnO (= 2 valence) has a peak near 100 ppm, SnO ₂ (= 4 valences) appears around -600 ppm. Thus, when it has the same ligand, since a night shift largely depends on the valence of Sn which is a central metal, it becomes possible to determine the valence at the peak position obtained by ₁₁₉ Sn-NMR measurement.

  A small amount of impurity elements may be intentionally mixed in the negative electrode material of the present invention. Examples of impurity elements include transition metals (Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, and lanthanoids. Group metals, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg) and periodic table group 17 elements (F, Cl). Further, dopants of various compounds (for example, Sb, In, and Nb compounds) that increase electron conductivity may be included.

Although the example of the negative electrode material of this invention is shown below, this invention is not limited to these. SnAl _0.4 B _0.5 P _0.5 K _0.1 O _3.65 , SnAl _0.4 B _0.5 P _0.5 Na _0.2 O _3.7 , SnAl _0.4 B _0.3 P _0.5 Rb _0.2 O _3.4 , SnAl _0.4 B _0.5 P _0.5 Cs _0.1 O _3.65 , SnAl _0.4 B _0.5 P _0.5 K _0.1 Ge _0.05 O _3.85 , SnAl _0.4 B _0.5 P _0.5 K _0.1 Mg _0.1 Ge _0.02 O _3.83 , SnAl _0.4 B _0.4 P _0.4 O _3.2 , SnAl _0.3 B _0.5 P _0.2 O _2.7 , SnAl _0.3 B _0.5 P _0.2 O _2.7 , SnAl _0.4 B _0.5 P _0.3 Ba _0.08 Mg _0.08 O _3.26 , SnAl _0.4 B _0.4 P _0.4 Ba _0.08 O _3.28 , SnAl _0.4 B _0.5 P _0.5 O _3.6 , SnAl _0.4 B _0.5 P _0.5 Mg _0.1 O _3.7 .

SnAl _0.5 B _0.4 P _0.5 Mg _0.1 F _0.2 O _3.65 , SnB _0.5 P _0.5 Li _0.1 Mg _0.1 F _0.2 O _3.05 , SnB _0.5 P _0.5 K _0.1 Mg _0.1 F _0.2 O _3.05 , SnB _0.5 P _0.5 K _0.05 Mg _0.05 F _0.1 O _3.03 , SnB _0.5 P _0.5 K _0.05 Mg _0.1 F _0.2 O _3.03 , SnAl _0.4 B _0.5 P _0.5 Cs _0.1 Mg _0.1 F _0.2 O _3.65 , SnB _0.5 P _0.5 Cs _0.05 Mg _0.05 F _0.1 O _3.03 , SnB _0.5 P _0.5 Mg _0.1 F _{0.1 O 3.05, SnB 0.5 P 0.5} Mg 0.1 F 0.2 O 3, SnB 0.5 P 0.5 Mg 0.1 F 0.06 O 3.07, SnB 0.5 P 0.5 Mg 0.1 F 0.14 O 3.03, SnPBa 0.08 O 3.58, SnPK 0.1 O 3.55, SnPK 0.05 Mg _{0.05 O 3.58, SnPCs 0.1 O 3.55} , SnPBa 0.08 F 0.08 O 3.54, SnPK 0.1 Mg 0.1 F 0.2 O 3.55, SnPK 0.05 Mg 0.05 F 0.1 O 3.53, SnPCs 0.1 Mg 0.1 F 0.2 O 3.55, Sn _{Cs 0.05 Mg 0.05 F 0.1 O 3.53} .

Sn _1.1 Al _0.4 B _0.2 P _0.6 Ba _0.08 F _0.08 O _3.54 , Sn _1.1 Al _0.4 B _0.2 P _0.6 Li _0.1 K _0.1 Ba _0.1 F _0.1 O _3.65 , Sn _1.1 Al _0.4 B _0.4 P _0.4 Ba _0.08 O _3.34 , Sn _1.1 Al _0.4 PCs _0.05 O _4.23 , Sn _1.1 Al _0.4 PK _0.05 O _4.23 , Sn _1.2 Al _0.5 B _0.3 P _0.4 Cs _0.2 O _3.5 , Sn _1.2 Al _0.4 B _0.2 P _0.6 Ba _0.08 O _3.68 , Sn _1.2 Al _0.4 B _0.2 P _0.6 Ba _0.08 F _0.08 O _3.64 , Sn _1.2 Al _0.4 B _0.2 P _0.6 Mg _0.04 Ba _0.04 O _3.68 , Sn _1.2 Al _0.4 B _0.3 P _0.5 Ba _0.08 O _3.58 , Sn _1.3 Al _0.3 B _0.3 P _0.4 Na _0.2 O _3.3 , Sn _1.3 Al _0.2 B _0.4 P _0.4 Ca _0.2 O _3.4 , Sn _1.3 Al _0.4 B _0.4 P _0.4 Ba _0.2 O _3.6 , Sn _1.4 Al _0.4 PK _0.2 O _4.6 , Sn _1.4 Al _0.2 Ba _0.1 PK _0.2 O _4.45 , Sn _1.4 Al _0.2 Ba _0.2 PK _0.2 O _4.6 , Sn _1.4 Al _{0. 4} Ba _0.2 PK _0.2 Ba _0.1 F _0.2 O _4.9 , Sn _1.4 Al _0.4 PK _0.3 O _4.65 , Sn _1.5 Al _0.2 PK _0.2 O _4.4 , Sn _1.5 Al _0.4 PK _0.1 O _4.65 , Sn _1.5 Al _0.4 PCs _0.05 O _4.63 , Sn _1.5 Al _0.4 PCs _0.05 Mg _0.1 F _0.2 O _4.63 .

_{SnSi 0.5 Al 0.1 B 0.2 P 0.1} Ca 0.4 O 3.1, SnSi 0.4 Al 0.2 B 0.4 O 2.7, SnSi 0.5 Al 0.2 B 0.1 P 0.1 Mg 0.1 O 2.8, SnSi 0.6 Al 0.2 B 0.2 O 2.8, SnSi 0.5 Al 0.3 B 0.4 P _0.2 O _3.55 , SnSi _0.5 Al _0.3 B _0.4 P _0.5 O _4.30 , SnSi _0.6 Al _0.1 B _0.1 P _0.3 O _3.25 , SnSi _0.6 Al _0.1 B _0.1 P _0.1 Ba _0.2 O _2.95 , SnSi _0.6 Al _0.1 B _0.1 P _0.1 Ca _0.2 O _2.95 , SnSi _0.6 Al _0.4 B _0.2 Mg _0.1 O _3.2 , SnSi _0.6 Al _0.1 B _0.3 P _0.1 O _3.05 , SnSi _0.6 Al _0.2 Mg _0.2 O _2.7 , SnSi _0.6 Al _0.2 Ca _0.2 O _2.7 , SnSi _0.6 Al _0.2 P _0.2 O _{3, SnSi 0.6 B 0.2 P 0.2} O 3, SnSi 0.8 Al 0.2 O 2.9, SnSi 0.8 Al 0.3 B 0.2 P 0.2 O 3.85, SnSi 0.8 B 0.2 O 2.9, SnSi 0.8 Ba 0.2 O 2.8, _{nSi 0.8 Mg 0.2 O 2.8, SnSi} 0.8 Ca 0.2 O 2.8, SnSi 0.8 P 0.2 O 3.1.

Sn _0.9 Mn _0.3 B _0.4 P _0.4 Ca _0.1 Rb _0.1 O _2.95 , Sn _0.9 Fe _0.3 B _0.4 P _0.4 Ca _0.1 Rb _0.1 O _2.95 , Sn _0.8 Pb _0.2 Ca _0.1 P _0.9 O _3.35 , Sn _0.3 Ge _0.7 Ba _0.1 P _0.9 O _{3.35, Sn 0.9 Mn 0.1 Mg 0.1} P 0.9 O 3.35, Sn 0.2 Mn 0.8 Mg 0.1 P 0.9 O 3.35, Sn 0.7 Pb 0.3 Ca 0.1 P 0.9 O 3.35, Sn 0.2 Ge 0.8 Ba 0.1 P 0.9 O 3.35.

The negative electrode material of the present invention can be synthesized by a firing method or a welding method. For example, the firing method will be described in detail. M ¹ compound, M ² compound and M ⁴ compound (M ¹ and M ² are different, Si, Ge, Sn, Pb, P, B, Al, Sb and M ₄ are Mg, Ca , Sr, Ba) may be mixed and fired.

Examples of Sn compounds include SnO, SnO ₂ , Sn ₂ O ₃ , Sn ₃ O ₄ , Sn ₇ O ₁₃ .H ₂ O, Sn ₈ O ₁₅ , stannous hydroxide, stannic oxyhydroxide, stannic acid , Stannous oxalate, stannous phosphate, orthostannic acid, metastannic acid, parastannic acid, stannous fluoride, stannous fluoride, stannous chloride, stannous chloride, stannous pyrophosphate , Tin phosphide, stannous sulfide, stannic sulfide, and the like. Examples of the Si compound include organic silicon compounds such as SiO ₂ , SiO, tetramethylsilane and tetraethylsilane, alkoxysilane compounds such as tetramethoxysilane and tetraethoxysilane, and hydrosilane compounds such as trichlorohydrosilane. Examples of the Ge compound include GeO ₂ , GeO, germanium tetramethoxide, germanium tetraethoxide, and other alkoxygermanium compounds. Examples of Pb compounds include PbO ₂ , PbO, Pb ₂ O ₃ , Pb ₃ O ₄ , lead nitrate, lead carbonate, lead formate, lead acetate, lead tetraacetate, lead tartrate, lead diethoxide, lead di (isopropoxide), etc. Can be mentioned. Examples of the P compound include phosphorus pentoxide, phosphorus oxychloride, phosphorus pentachloride, phosphorus trichloride, phosphorus tribromide, trimethyl phosphate, triethyl phosphate, tripropyl phosphate, stannous pyrophosphate, boron phosphate and the like. Can be mentioned. Examples of the B compound include boron trioxide, boron trichloride, boron tribromide, boron carbide, boric acid, trimethyl borate, triethyl borate, tripropyl borate, tributyl borate, boron phosphide, boron phosphate and the like. Examples of the Al compound include aluminum oxide (α-alumina, β-alumina), aluminum silicate, aluminum tri-iso-propoxide, aluminum tellurite, aluminum chloride, aluminum boride, aluminum phosphide, aluminum phosphate, and lactic acid. Examples thereof include aluminum, aluminum borate, aluminum sulfide, aluminum sulfate, and aluminum boride. Examples of the Sb compound include diantimony trioxide and triphenylantimony. Examples of the Mg, Ca, Sr, and Ba compounds include respective oxide salts, hydroxide salts, carbonates, phosphates, sulfates, nitrates, and the like.

  As firing conditions, it is preferable that the temperature rising rate is 4 ° C. or more and 200 ° C. or less per minute. A preferable firing temperature is 300 ° C. or higher and 1500 ° C. or lower. A preferable firing time is 10 minutes or more and 50 hours or less. The temperature decreasing rate is preferably 2 ° C. or more and 200 ° C. or less per minute. The rate of temperature increase in the present invention is the average rate of temperature rise from “50% of the firing temperature (indicated in ° C.)” to “80% of the firing temperature (indicated in ° C.)”. It is the average rate of temperature drop from reaching “80% of the firing temperature (indicated by ° C.)” to “50% of the firing temperature (expressed in ° C)”. The temperature lowering may be cooled in a firing furnace, or taken out of the firing furnace and cooled, for example, in water. In addition, a super rapid cooling method such as the gun method, Hammer-Anvil method, slap method, gas atomization method, plasma spray method, centrifugal quenching method, or melt drag method described on page 217 of ceramics processing (Gihodo Publishing 1987) can also be used. Moreover, you may cool using the single-roller method of a new glass handbook (Maruzen 1991) 172 page, and the double roller method. In the case of a material that melts during firing, the fired product may be continuously taken out while supplying raw materials during firing. In the case of a material that melts during firing, it is preferable to stir the melt.

  The firing gas atmosphere is preferably an atmosphere having an oxygen content of 5% by volume or less, and more preferably an inert gas atmosphere. Examples of the inert gas include nitrogen, argon, helium, krypton, and xenon. The chemical formula of the compound obtained by firing can be calculated from an inductively coupled plasma (ICP) emission spectroscopic analysis method as a measurement method and a weight difference between powders before and after firing as a simple method.

  The negative electrode material of the present invention is pulverized and classified to have a predetermined particle size. Well-known pulverizers and classifiers (for example, mortar, ball mill, sand mill, vibration ball mill, satellite ball mill, planetary ball mill, swirling airflow jet mill, and sieve) are used for pulverization and classification. When pulverizing, wet pulverization in the presence of water or an organic solvent such as methanol can be performed as necessary. There is no particular limitation on the classification method, and a sieve, an air classifier, a water tank, or the like can be used as necessary. The average particle size is preferably 0.1 to 60 μm, particularly preferably 1.0 to 30 μm, and further preferably 2.0 to 20 μm.

  The conductive agent used in the present invention may be anything as long as it is an electron conductive material that does not cause a chemical change in the constructed battery. Specific examples include natural graphite such as scaly graphite, flake graphite, and earthy graphite, petroleum coke, coal coke, celluloses, saccharides, high-temperature fired bodies such as mesophase pitch, artificial graphite such as vapor-grown graphite, etc. Graphite, carbon black such as acetylene black, furnace black, ketjen black, channel black, lamp black, thermal black, carbon materials such as asphalt pitch, coal tar, activated carbon, mesofuse pitch, polyacene, metal fibers, etc. Examples thereof include conductive fibers, metal powders such as copper, nickel, aluminum, and silver, conductive whiskers such as zinc oxide and potassium titanate, and conductive metal oxides such as titanium oxide. Of these, graphite and carbon black are preferred. These may be used singly or as a mixture. The addition amount of the conductive agent to the mixture layer is preferably 6 to 50% by weight with respect to the negative electrode material or the positive electrode material. In particular, it is preferably 6 to 30% by weight. In the case of carbon black or graphite, the content is particularly preferably 6 to 20% by weight.

  In the present invention, a binder is used to hold the electrode mixture. Examples of the binder include polysaccharides, thermoplastic resins, and polymers having rubber elasticity. Preferred binders include starch, carboxymethyl cellulose, cellulose, diacetyl cellulose, methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, sodium alginate, polyacrylic acid, polyacrylic acid Na, polyvinyl phenol, polyvinyl methyl ether, polyvinyl alcohol, polyvinyl pyrrolidone. , Polyacrylamide, polyhydroxy (meth) acrylate, water-soluble polymers such as styrene-maleic acid copolymer, polyvinyl chloride, polytetrafluoroethylene, polyvinylidene fluoride, tetrafluoroethylene-hexafluoropropylene copolymer, vinylideneflour Ride-tetrafluoroethylene-hexafluoropropylene copolymer, polyethylene, polypropylene, ethylene-propylene (Meth) acrylic acid ester copolymers containing (meth) acrylic acid esters such as methyl-diene terpolymer (EPDM), sulfonated EPDM, polyvinyl acetal resin, methyl methacrylate, 2-ethylhexyl acrylate, (meth) acrylic Acid ester-acrylonitrile copolymer, polyvinyl ester copolymer containing vinyl ester such as vinyl acetate, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, polybutadiene, neoprene rubber, fluoro rubber, polyethylene oxide, polyester polyurethane Resin, polyether polyurethane resin, polycarbonate polyurethane resin, polyester resin, phenol resin, epoxy resin emulsion (latex) or suspension It can be cited. In particular, polyacrylate ester latex, carboxymethyl cellulose, polytetrafluoroethylene, and polyvinylidene fluoride are exemplified. These binders can be used alone or in combination. When the amount of the binder added is small, the holding power and cohesion of the electrode mixture is weak. If the amount is too large, the electrode volume increases and the capacity per electrode unit volume or unit weight decreases. For this reason, the addition amount of the binder is preferably 1 to 30% by weight, and particularly preferably 2 to 10% by weight.

  Any filler can be used as long as it is a fibrous material that does not cause a chemical change in the constructed battery. Usually, olefin polymers such as polypropylene and polyethylene, fibers such as glass and carbon are used. Although the addition amount of a filler is not specifically limited, 0 to 30 weight% is preferable. As the ionic conductive agent, those known as inorganic and organic solid electrolytes can be used, and details are described in the section of the electrolytic solution. A pressure enhancer is a compound that increases the internal pressure described later, and carbonate is a typical example.

  In the current collector that can be used in the present invention, the positive electrode is aluminum, stainless steel, nickel, titanium, or an alloy thereof, and the negative electrode is copper, stainless steel, nickel, titanium, or an alloy thereof. The form of the current collector is foil, expanded metal, punching metal, or wire mesh. In particular, an aluminum foil is preferable for the positive electrode and a copper foil is preferable for the negative electrode.

  The separator that can be used in the present invention is only required to have a large ion permeability, a predetermined mechanical strength, and an insulating thin film. As a material, ophylene-based polymer, fluorine-based polymer, cellulose-based polymer, polyimide, nylon, Glass fiber and alumina fiber are used, and as a form, a nonwoven fabric, a woven fabric, and a microporous film are used. In particular, polypropylene, polyethylene, a mixture of polypropylene and polyethylene, a mixture of polypropylene and Teflon, and a mixture of polyethylene and Teflon are preferable as the material, and a microporous film is preferable as the form. In particular, a microporous film having a pore diameter of 0.01 to 1 μm and a thickness of 5 to 50 μm is preferable.

The electrolytic solution is generally composed of a supporting salt and a solvent. Lithium salt is mainly used as the supporting salt in the lithium secondary battery. The lithium salt can be used in the present invention, for _{example, LiClO 4, LiBF 4, LiPF} 6, LiCF 3 SO 3, LiCF 3 CO 2, LiAsF 6, LiSbF 6, LiB 10 Cl 10, lower aliphatic lithium carboxylate, LiAlCl ₄ , LiCl, LiBr, LiI, chloroborane lithium, lithium tetraphenylborate and the like can be mentioned, and one kind or a mixture of two or more kinds can be used. Of these, a solution in which LiBF ₄ and / or LiPF ₆ is dissolved is preferable. The concentration of the supporting salt is not particularly limited, but is preferably 0.2 to 3 mol per liter of the electrolytic solution.

Solvents that can be used in the present invention include propylene carbonate, ethylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, γ-butyrolactone, methyl formate, methyl acetate, 1,2-dimethoxyethane, tetrahydrofuran, and 2-methyl. Tetrahydrofuran, dimethyl sulfoxide, 1,3-dioxolane, formamide, dimethylformamide, dioxolane, dioxane, acetonitrile, nitromethane, ethyl monoglyme, phosphoric acid triester, trimethoxymethane, dioxolane derivative, sulfolane, 3-methyl-2-oxazolidinone, Aprotic such as propylene carbonate derivative, tetrahydrofuran derivative, ethyl ether, 1,3-propane sultone Machine solvent can be cited, to use a mixture of alone or in combination. Among these, carbonate-based solvents are preferable, and it is particularly preferable to use a mixture of a cyclic carbonate and an acyclic carbonate. As the cyclic carbonate, ethylene carbonate and propylene carbonate are preferable. Moreover, as an acyclic carbonate, diethyl carbonate, dimethyl carbonate, and methyl ethyl carbonate are preferable. Examples of the electrolytic solution that can be used in the present invention include LiCF ₃ SO ₃ , LiClO ₄ , LiBF ₄ and / or LiPF ₆ in an electrolytic solution in which ethylene carbonate, propylene carbonate, 1,2-dimethoxyethane, dimethyl carbonate or diethyl carbonate is appropriately mixed. An electrolytic solution containing is preferable. In particular, an electrolysis containing at least one salt selected from LiCF ₃ SO ₃ , LiClO ₄ , or LiBF ₄ and LiPF ₆ in a mixed solvent of at least one of propylene carbonate or ethylene carbonate and at least one of dimethyl carbonate or diethyl carbonate. Liquid is preferred. The amount of the electrolyte added to the battery is not particularly limited, and can be used depending on the amount of the positive electrode material or the negative electrode material or the size of the battery.

In addition to the electrolytic solution, the following solid electrolyte can be used in combination. The solid electrolyte is classified into an inorganic solid electrolyte and an organic solid electrolyte. Inorganic solid electrolytes include Li nitride,
Halides and oxyacid salts are well known. Among _{them, Li 3 N, LiI, Li} 5 NI 2, Li 3 N-LiI-LiOH, Li 4 SiO 4, Li 4 SiO 4 -LiI-LiOH, xLi 3 PO 4 - (1-x) Li 4 SiO 4 Li ₂ SiS ₃ , phosphorus sulfide compounds and the like are effective. In the organic solid electrolyte, a polyethylene oxide derivative or a polymer containing the derivative, a polypropylene oxide derivative or a polymer containing the derivative, a polymer containing an ion dissociation group, a mixture of a polymer containing an ion dissociation group and the above aprotic electrolyte, phosphoric acid A polymer matrix material containing an ester polymer and an aprotic polar solvent is effective. Furthermore, there is a method of adding polyacrylonitrile to the electrolytic solution. A method of using an inorganic and organic solid electrolyte in combination is also known.

Further, other compounds may be added to the electrolyte for the purpose of improving discharge and charge / discharge characteristics. For example, pyridine, triethyl phosphite, triethanolamine, cyclic ether, ethylenediamine, n-glyme, hexaphosphoric acid triamide, nitrobenzene derivative, sulfur, quinoneimine dye, N-substituted oxazolidinone and N, N′-substituted imidazolidinone, ethylene glycol dialkyl ether , Quaternary ammonium salt, polyethylene glycol, pyrrole, 2-methoxyethanol, AlCl ₃ , conductive polymer electrode active material monomer, triethylenephosphoramide, trialkylphosphine, morpholine, aryl compound having carbonyl group, 12- Crown ethers such as crown-4, hexamethylphosphoric triamide and 4-alkylmorpholine, bicyclic tertiary amine, oil, quaternary phosphonium salt, tertiary sulfoni Examples thereof include um salt.

  In order to make the electrolyte nonflammable, a halogen-containing solvent such as carbon tetrachloride or ethylene trifluoride chloride can be contained in the electrolyte. In addition, carbon dioxide gas can be included in the electrolytic solution in order to make it suitable for high-temperature storage.

  The entire amount of the electrolytic solution may be injected once, but it is preferable to inject it in two or more times. When the injection is divided into two or more times, each liquid may have the same composition or a different composition (for example, a non-aqueous solvent or a non-aqueous solvent having a higher viscosity than the solvent after injecting a solution in which a lithium salt is dissolved with a non-aqueous solvent). Or a solution obtained by dissolving a lithium salt in a solvent or a non-aqueous solvent). In order to shorten the time for injecting the electrolyte, etc., the battery can may be decompressed, or centrifugal force or ultrasonic waves may be applied to the battery can.

  Battery cans and battery lids that can be used in the present invention are nickel-plated steel plates, stainless steel plates (SUS304, SUS304L, SUS304N, SUS316, SUS430, SUS444, etc.), nickel-plated stainless steel plates (same as above) , Aluminum or an alloy thereof, nickel, titanium, and copper, and the shapes are a true circular cylinder, an elliptical cylinder, a square cylinder, and a rectangular cylinder. In particular, when the outer can also serves as the negative electrode terminal, a stainless steel plate and a nickel-plated steel plate are preferable, and when the outer can also serves as the positive electrode terminal, a stainless steel plate, aluminum, or an alloy thereof is preferable. The shape of the battery can may be any of buttons, coins, sheets, cylinders, and corners. A safety valve can be used for the sealing plate as a countermeasure against an increase in the internal pressure of the battery can. In addition, a method of cutting a member such as a battery can or a gasket can be used. In addition, various conventionally known safety elements (for example, fuses, bimetals, PTC elements, etc. as overcurrent prevention elements) may be provided.

  For the lead plate used in the present invention, a metal having electrical conductivity (for example, iron, nickel, titanium, chromium, molybdenum, copper, aluminum, etc.) or an alloy thereof can be used. As a method for welding the battery lid, battery can, electrode sheet, and lead plate, a known method (eg, DC or AC electric welding, laser welding, ultrasonic welding) can be used. As the sealing agent for sealing, a conventionally known compound or mixture such as asphalt can be used.

  Gaskets that can be used in the present invention are olefin polymers, fluoropolymers, cellulose polymers, polyimides, and polyamides as materials. Olefin polymers are preferred from the viewpoint of organic solvent resistance and low moisture permeability, and are mainly composed of propylene. Polymers are preferred. Furthermore, a block copolymer of propylene and ethylene is preferable.

The battery of the present invention is covered with an exterior material as necessary. As exterior materials, heat shrinkable tubes,
There are adhesive tape, metal film, paper, cloth, paint, plastic case and so on. Further, at least a part of the exterior may be provided with a portion that changes color by heat so that the heat history during use can be known.

  A plurality of the batteries of the present invention are assembled in series and / or in parallel as needed, and stored in a battery pack. In addition to safety elements such as positive temperature coefficient resistors, temperature fuses, fuses and / or current interrupting elements, the battery pack also requires safety circuits (monitoring the voltage, temperature, current, etc. of each battery and / or the entire battery pack) In this case, a circuit having a function of interrupting current may be provided. In addition to the positive and negative terminals of the entire assembled battery, the battery pack should be provided with the positive and negative terminals of each battery, the entire assembled battery, the temperature detection terminal of each battery, the current detection terminal of the entire assembled battery, etc. as external terminals. You can also. The battery pack may incorporate a voltage conversion circuit (such as a DC-DC converter). The connection of each battery may be fixed by welding a lead plate, or may be fixed so that it can be easily attached and detached with a socket or the like. Further, the battery pack may be provided with display functions such as the remaining battery capacity, the presence / absence of charging, and the number of uses.

  The battery of the present invention is used in various devices. In particular, video movies, portable video decks with built-in monitors, movie cameras with built-in monitors, compact cameras, single-lens reflex cameras, film with lenses, notebook computers, notebook word processors, electronic notebooks, mobile phones, cordless phones, shavings, power tools, It is preferably used for electric mixers, automobiles and the like.

Hereinafter, the present invention will be described in more detail with reference to specific examples. However, the present invention is not limited to the examples unless it exceeds the gist of the invention.
Example-1
[Creation of positive electrode mixture paste]
Cathode material: LiCoO ₂ (mixed in a molar ratio of lithium carbonate and tricobalt tetroxide in a ratio of 3: 2 is placed in an alumina crucible, heated to 750 ° C. at 2 ° C./min in the air, and calcined for 4 hours. Further, the temperature was raised to 900 ° C. at a rate of 2 ° C. per minute, baked and pulverized for 8 hours at that temperature, and the electrical conductivity of the dispersion when the center particle size was 5 μm and 50 g of the washed product was dispersed in 100 ml of water. 0.6 mS / m, pH 10.1, specific surface area measured by the nitrogen adsorption method and 200g of acetylene black 10g of 0.42 m ² / g), it was mixed with a homogenizer, followed by 2-ethylhexyl acrylate as a binder 8 g of an aqueous dispersion of a copolymer of acrylic acid and acrylonitrile (solid content concentration 50% by weight) and 60 g of a 2% by weight aqueous solution of carboxymethyl cellulose were added and kneaded and mixed. It was added 50 g, followed by stirring and mixing with a homogenizer to prepare a positive electrode mixture paste.

[Creation of negative electrode mixture paste]
Negative electrode material; SnGe _0.1 B _0.5 P _0.58 Mg _0.1 K _0.1 O _3.35 (6.7 g of tin monoxide, 10.3 g of tin pyrophosphate, 1.7 g of diboron trioxide, 0.7 g of potassium carbonate, 0.4 g of magnesium oxide, Germanium dioxide (1.0 g) was dry-mixed, placed in an alumina crucible, heated to 1000 ° C. at 15 ° C./min in an argon atmosphere, baked at 1100 ° C. for 12 hours, and then cooled to room temperature at 10 ° C./min. What is collected from the firing furnace, jet mill pulverized, has an average particle size of 4.5 μm, and has a broad peak with a peak at around 28 ° in the 2θ value in the X-ray diffraction method using CuKα rays. No crystalline diffraction line was observed when the 2θ value was 40 ° or more and 70 ° or less.) Was mixed with 200 g and a conductive agent (artificial graphite) 30 g with a homogenizer, and the concentration was 2 as a binder. A negative electrode mixture paste was prepared by adding 50 g of a weight% aqueous carboxymethyl cellulose solution and 10 g of polyvinylidene fluoride and mixing them with 30 g of water and further kneading and mixing.

[Creation of positive and negative electrode sheets]
After applying the positive electrode mixture paste prepared above on both sides of an aluminum foil current collector having a thickness of 30 μm with a blade coater so that the coating amount is 400 g / m ² and the thickness of the compressed sheet is 280 μm, and drying. Then, it was compression-molded with a roller press and cut into a predetermined size to produce a belt-like positive electrode sheet. Furthermore, it was sufficiently dehydrated and dried with a far-infrared heater in a dry box (dew point: dry air of −50 ° C. or lower) to prepare a positive electrode sheet. Similarly, a negative electrode mixture paste was applied to a 20 μm copper foil current collector, and a negative electrode sheet having a coating amount of 70 g / m ² and a compressed sheet thickness of 90 μm was prepared in the same manner as the above positive electrode sheet. did.
(Electrolyte preparation)
In an argon atmosphere, 65.3 g of diethyl carbonate was placed in a 200 cc narrow-neck polypropylene container, and 22.2 g of ethylene carbonate was dissolved little by little while taking care not to exceed a liquid temperature of 30 ° C. Next, 0.4 g of LiBF ₄ and 12.1 g of LiPF ₆ were dissolved in a small amount in the polypropylene container in order while paying attention not to exceed 30 ° C. The obtained electrolytic solution (electrolytic solution 1) was a colorless transparent liquid with a specific gravity of 1.135. Moisture was 18 ppm (measured with a Kyoto Electronics trade name MKC-210 type Karl Fischer moisture measuring device), free acid content was 24 ppm (measured by neutralization titration with 0.1 N NaOH aqueous solution using bromthymol blue as an indicator) )Met. Further, the electrolytes 2 to 18 were prepared by dissolving the compounds shown in Table 1 in this electrolytic solution 1 so as to have a predetermined concentration.

Table 1 Electrolyte ────────────────────────────────────
Electrolyte number Additive Additive concentration (wt%)
────────────────────────────────────
1 None −
2 Exemplary compound (1) 1
3 Exemplary Compound (3) 1
4 Exemplary compound (5) 1
5 Exemplary compound (7) 1
6 Exemplary Compound (9) 1
7 Exemplary compound (12) 1
8 Exemplary compound (13) 1
9 Exemplary compound (14) 1
10 Exemplary compound (15) 1
11 Exemplary Compound (16) 1
12 Exemplary compound (17) 1
13 Exemplary Compound (19) 1
14 Exemplary Compound (20) 1
15 Exemplary compound (12) 0.2
16 Exemplary compound (12) 0.5
17 Exemplified compound (12) 2
18 Exemplary Compound (12) 5
────────────────────────────────────

[Creation of cylinder battery]
A positive electrode sheet, a microporous polypropylene film separator, a negative electrode sheet and a separator were laminated in this order, and this was wound in a spiral shape. Eighteen pieces were prepared by storing the wound body in an iron-bottomed cylindrical battery can with nickel plating that also serves as a negative electrode terminal. Electrolytic solutions 1 to 18 were respectively injected into each battery can, and a battery lid having a positive electrode terminal was crimped through a gasket to produce a cylindrical battery (1 to 18).

Example-2
Cylindrical batteries (battery numbers 1a to 10a) were prepared in the same manner as in Example 1 except that graphite powder was used as the negative electrode material. About the battery created by said method, charging / discharging was repeated on conditions with a current density of 4.8 mA / cm < ² >, the end-of-charge voltage of 4.1V, and the end-of-discharge voltage of 2.8V, and the discharge capacity in each cycle was calculated | required. Tables 2 and 3 show the relative capacity of the batteries (the capacity of the first cycle of each battery normalized by the capacity of the battery 1) and the cycle characteristics (the 300th cycle relative to the discharge capacity of the first cycle of each battery). The ratio of the discharge capacity).

Table 2 Performance of the created non-aqueous secondary battery ────────────────────────────────────
Electrolyte No. Additive Additive Concentration (wt%) Relative Capacity Cycling ─────────────────────────────────── ──
1 None-1 0.65
2 Exemplary compound (1) 1 0.99 0.74
3 Exemplary Compound (3) 1 1.01 0.78
4 exemplary compound (5) 1 1.00 0.73
5 Exemplary compound (7) 1 1.00 0.73
6 Exemplary Compound (9) 1 1.01 0.75
7 Exemplary compound (12) 1 0.99 0.85
8 Exemplary compound (13) 1 0.99 0.84
9 Exemplary compound (14) 1 1.00 0.80
10 Exemplary compound (15) 1 0.99 0.81
11 Exemplified Compound (16) 1 1.02 0.81
12 Exemplary compound (17) 1 0.99 0.83
13 Exemplary Compound (19) 1 1.01 0.74
14 Exemplary Compound (20) 1 1.00 0.85
15 Exemplary compound (12) 0.2 1.00 0.71
16 Exemplary compound (12) 0.5 0.99 0.75
17 Exemplary compound (12) 2 0.98 0.82
18 Exemplified Compound (12) 5 0.97 0.80
────────────────────────────────────

Table 3 Performance of the created non-aqueous secondary battery ────────────────────────────────────
Electrolyte No. Additive Additive Concentration (wt%) Relative Capacity Cycling ─────────────────────────────────── ──
1a None-0.83 0.70
2a Exemplary compound (1) 1 0.84 0.73
3a Exemplary compound (3) 1 0.82 0.70
4a Exemplary compound (5) 1 0.83 0.73
5a Exemplary Compound (7) 1 0.83 0.72
6a Exemplary compound (9) 1 0.84 0.73
7a Exemplary compound (12) 1 0.84 0.71
8a Exemplary compound (13) 1 0.83 0.70
9a Exemplary compound (14) 1 0.83 0.71
10a Exemplary compound (15) 1 0.82 0.71
────────────────────────────────────

  From Table 2 and Table 3, it can be seen that when the compound represented by the general formula (1) is added, the cycleability is improved. Among these, when the exemplified compounds 12, 13, 14, 15, 16, 17, 19, and 20 are added, the effect is remarkable. In view of the effect of the addition amount of the exemplified compound (12), it is preferable that the addition concentration is 1 weight percent because of good cycleability. When graphite is used as the negative electrode material, the capacity is small from the beginning.

Sectional drawing of the cylinder type battery used for the Example is shown.

Explanation of symbols

1 Polypropylene gasket 2 Negative electrode can also serves as negative electrode terminal (battery can)
3 Separator 4 Negative electrode sheet 5 Positive electrode sheet 6 Non-aqueous electrolyte 7 Explosion-proof valve body 8 Battery cover that also serves as a positive electrode terminal 9 PTC terminal 10 Internal lid body 11 Ring

Claims (2)

A method for producing a non-aqueous electrolyte for a lithium secondary battery comprising a mixed solvent, a supporting salt and a compound for preventing oxidative decomposition,
Liquid temperature diethyl carbonate as a non-cyclic carbonate so as not to exceed 30 ° C., dimethyl carbonate, a mixed solvent to prepare the mixed solvent was added ethylene carbonate as any one or more cyclic carbonate selected from methyl ethyl carbonate prepared Process,
Subsequent to the mixed solvent preparation step, LiBF ₄ and / or LiPF ₆ which is a lithium salt as the supporting salt is added to the mixed solvent with respect to 1 liter of the non-aqueous electrolyte so that the liquid temperature does not exceed 30 ° C. A supporting salt addition step of adding a small amount at a time so as to obtain a concentration of 2 to 3 mol;
Following the supporting salt addition step, a step of adding a compound of the following general formula (1) as the compound to 1 g to 50 g in 1 kg of the non-aqueous electrolyte solution and dissolving it;
The manufacturing method of the non-aqueous electrolyte for lithium secondary batteries characterized by including.

R ₁₁ —CH—R ₁₃ (1)
｜
R ₁₂

[R ₁₁ represents a substituted or unsubstituted aryl group having 6 to 24 carbon atoms in total;
R ₁₂ and R ₁₃ each represents a substituted or unsubstituted alkyl group having 1 to 24 carbon atoms, which is an electron donating group. R ₁₁ , R ₁₂ and R ₁₃ may combine with each other to form a ring. ]   The method for producing a non-aqueous electrolyte for a lithium secondary battery according to claim 1, wherein the method for producing the non-aqueous electrolyte further includes a step of measuring specific gravity, moisture, and free acid content.