JP2003272626A - Nonaqueous electrolyte battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a nonaqueous electrolyte battery capable of stably operating even if kept unattended under a temperature condition of 100°C or higher. <P>SOLUTION: With a nonaqueous electrolyte battery provided with a positive electrode 1 with at least manganese dioxide or a complex compound of manganese dioxide and manganese dilithium trioxide, a negative electrode 5 and a separator 3, a vacancy volume with a pre diameter of the positive electrode active material 1 within the range of 30 Å to 40 Å is to be 0.05 cc/g or less. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-aqueous electrolyte battery, and more particularly to a non-aqueous electrolyte battery that can be used even in a high temperature environment of 100 ° C. or higher or after high temperature storage.

[0002]

2. Description of the Related Art In recent years, a lithium battery has been developed as a small-sized non-aqueous electrolyte battery having a high voltage and a high energy density, and a portable personal computer,
It is used in a wide range of applications as a memory backup power supply for portable information terminals (PDAs), mobile phones, etc., and as a drive power supply for cameras, digital cameras, automobile equipment (car stereos, ETC equipment, etc.).

Such an apparatus may be, for example, a CPU when left in fine weather or in a high load application.
It may be exposed to a temperature condition considerably higher than room temperature due to heat generation by the above, and in some cases, the temperature may be 100 ° C. or higher, or even 130 ° C. in some cases.

However, when the conventional non-aqueous electrolyte battery is left under such high temperature conditions, the non-aqueous electrolyte decomposes at about 70 ° C. and begins to generate gas such as carbon dioxide,
This causes blistering in the battery, making it impossible to contact the electrode of the battery and the outer casing, which causes deterioration of the battery characteristics such as an increase in internal resistance and a decrease in output. for that reason,
In the conventional non-aqueous electrolyte battery, the maximum storage temperature is generally about 70 ° C.

Various researches and developments have been carried out to improve the high temperature storage characteristics of such a non-aqueous electrolyte battery. For example,
An invention is an example described in JP-A-10-162860, this is the "general formula _{Li x M y Ni 1-y} O
₂ (However, M is Fe, V, Cu, Mg, Co, Mn, C
At least one metal selected from r and Al is used, x is in the range of 1.10 ≧ x ≧ 0.50, and y is in the range of 1> y ≧ 0. And a negative electrode composed of at least one selected from a carbon material or metal oxide capable of inserting and extracting lithium, a lithium alloy, a lithium metal, a lithium compound, and a conductive polymer. In the non-aqueous electrolyte secondary battery including a non-aqueous electrolyte, the lithium-containing composite oxide is a lithium-containing composite oxide having a space volume of 50 Å or less.
A non-aqueous electrolyte secondary battery, which is 0.003 cm ³ or less per gram. Invention (hereinafter, referred to as “cited invention”) is disclosed.

[0006] This cited invention has the effect of suppressing the deterioration of the battery performance when stored at 80 ° C in a charged state by providing the above-mentioned configuration. However, the above cited invention is very active for the decomposition reaction of the non-aqueous electrolyte, probably because Ni is contained in the positive electrode active material as an essential component, and is left under a temperature condition of at most 80 ° C. When it is left to stand at a temperature of 100 ° C. or higher, the amount of carbon dioxide generated by the decomposition of the electrolyte increases and the battery characteristics deteriorate, as in the case of the conventional non-aqueous electrolyte battery. Was recognized.

[0007]

DISCLOSURE OF THE INVENTION The inventors of the present application have solved the above-mentioned problems, and a non-aqueous electrolyte battery that can operate stably even after being left under a temperature condition of 100 ° C. or higher. For the purpose of obtaining, as a result of various studies on the composition and physical characteristics of the positive electrode active material, using manganese dioxide or a complex of manganese dioxide and dilithium manganese trioxide as the positive electrode active material, and its predetermined pore size range It has been found that by limiting the pore volume occupied by those to a predetermined numerical range, it is possible to obtain a non-aqueous electrolyte battery that is not easily deteriorated even if it is left under a temperature condition of 100 ° C. or higher,
The present invention has been completed.

That is, an object of the present invention is to provide a non-aqueous electrolyte battery which can be normally operated with little deterioration even when left at a high temperature of 100 ° C. or higher.

[0009]

The above object of the present invention can be achieved by adopting the following constitution. The present invention is a non-aqueous electrolyte battery having at least a positive electrode using manganese dioxide or a complex of manganese dioxide and dilithium manganese trioxide as a positive electrode active material, a negative electrode, and a separator, and the pore diameter of the positive electrode active material. Is 30 Å to 40 Å and the pore volume is 0.05 cc / g or less.

The positive electrode active material has a pore size of 30Å to 40Å
The pore volume in the range is 0.05 cc / g or less, 0.00
It is preferably 5 cc / g or more, and 0.05 cc / g
It is more preferably g or less and 0.01 cc / g or more.

In the above cited invention, a pore radius of 50 Å or less, that is, a pore volume of 100 Å or less is 0.003.
cm ³ While the following and required to be very small, the present invention is 0.05 cc / g or less pore volume of pore diameters in the range of 30Å~40Å preferably 0.05c
c / g or less 0.005 cc / g or more, more preferably 0.05 cc / g or less and 0.01 cc / g or more, which is larger than that of the above cited invention. The process to reduce it is easy.

In addition, since manganese dioxide is a raw material that is easily available and is inexpensive, the non-aqueous electrolyte battery of the present invention can be manufactured at a very low cost as compared with the above cited invention, and In the above cited invention, the maximum storage temperature is about 80 ° C. at most, whereas in the present invention, the maximum storage temperature can be increased to 100 ° C. or higher.

The exact reason why there is a difference between the pore volume in the required predetermined pore diameter range and the maximum storage temperature that can be achieved between the invention of the present application and the invention disclosed in the above cited publication is as follows. Although it is still unclear at this point in time and it is necessary to wait for future research, it is probable that Ni is an essential component as a constituent component of the positive electrode active material in the above cited invention, and the decomposition activity of this organic solvent of Ni is Since it is larger than Mn, which is an essential constituent component of the positive electrode active material, it is presumed that the above-mentioned result occurred.

[0014]

Example (Experimental example) First, manganese dioxide or a complex of manganese dioxide and dilithium manganese trioxide was synthesized, and those having various pore diameters and pore volumes were synthesized by changing the heat treatment temperature and the heat treatment time. . In addition, for the measurement of the pore diameter and the pore volume, a high-speed specific surface area / pore distribution measuring device “Asap 2000” manufactured by Shimadzu Corporation is used.
The pore distribution was measured by the log differential pore volume diagram (desorption side) of the BJH method by nitrogen adsorption / desorption.

The manganese dioxide or the complex of manganese dioxide and dilithium manganese trioxide used in the non-aqueous electrolyte battery is usually prepared by mixing electrolytic manganese dioxide powder at 350 ° C to 50 ° C.
It is used by removing water contained in manganese dioxide by heat treatment at 0 ° C. FIG. 6 shows the manganese dioxide (BET) produced by the electrolytic method used in the conventional example.
The specific surface area according to the method: 17.0 m ² / g) shows the relationship between the pore diameter and the pore volume. The pore diameter on the horizontal axis is on a logarithmic scale.

As is apparent from FIG. 6, manganese dioxide used as the positive electrode active material of the conventional non-aqueous electrolyte battery has pore volume peaks at pore diameters of about 35Å, about 80Å and about 500Å, respectively. About 35 of these
The peak of Å forms a sharp peak with a width of 30 Å to 40 Å. In this example, the pore volume of 30 Å to 40 Å is 0.125 cc / g, but the pore size is 30 Å
The pore volume of 40 Å is, for example, 4 times that of manganese dioxide.
When heat-treated at 90 ° C. for 4 hours, the size of the peak is significantly reduced as shown in FIG. 3, and is reduced to 0.032 cc / g.

Since the size of the peak over the pore diameters of 30Å to 40Å becomes smaller in proportion to the heat treatment temperature and the heat treatment time, various pore heat treatment conditions can be used to obtain a desired pore diameter in the range of 30Å to 40Å. Manganese dioxide having a void volume or a complex of manganese dioxide and dilithium manganese trioxide can be synthesized.

Here, the pore volume in the range of 30Å to 40Å is 0.01 cc / g, 0.027 cc / g, 0.032 c by varying the heat treatment conditions.
c / g, 0.05 cc / g, 0.06 cc / g and 0.
Six kinds of 125 cc / g samples were prepared. However, only the sample having a pore volume of 0.027 cc / g was a composite sample of manganese dioxide and dilithium manganese trioxide, and the other five kinds were all manganese dioxide. Log-differential pore volume distribution diagrams (desorption side) of the BJH method by nitrogen adsorption / desorption are shown in FIGS. 1 to 6 in order.

(Examples 1 to 4 and Comparative Examples 1 and 2) A non-aqueous electrolyte battery was assembled in the following manner using each of the above 6 types of samples. First, 90 parts by weight of the powder of each composite and 10 parts by weight of graphite as a conductive agent were mixed well, and 5 parts by weight of a dispersion liquid of polytetrafluoroethylene (PTFE) as a binder and 20 parts of pure water were mixed in this mixture. By adding parts by weight, kneading, pulverizing and sizing were performed to prepare a positive electrode mixture in a wet state.

This positive electrode mixture was pressure-molded at a pressure of 5 ton / cm ² to obtain 6 kinds of diameter 18 mm and thickness 1.5 mm.
A cylindrical positive electrode was prepared.

Next, a non-aqueous electrolyte battery as shown in FIG. 7 was manufactured. First, a negative electrode active material (diameter 20 mm, thickness 0.6 mm) made of lithium metal is fixed to a negative electrode can 6 via a current collector 7, and a separator 3 made of a nonwoven fabric is placed on the negative electrode.
And place 0.3 g of electrolyte on the separator 3.
Injected. The positive electrode prepared as described above was placed on this, and the positive electrode can 2 made of stainless steel was covered via the gasket 4 and caulked to obtain a battery having a thickness of 3.0 mm and an outer diameter of 24 mm.

The electrolytic solution used at this time is an organic solvent prepared by mixing propylene carbonate and diethylene glycol dimethyl ether in a volume ratio of 50:50 as a solvent.
The organic solvent to which 1M lithium perchlorate was added was used.

The following tests were carried out using the 6 types of non-aqueous electrolyte batteries thus prepared. First, each battery was stored in an environment of 100 ° C. for 10 days. The results of measuring the internal resistance and total height of the battery before and after storage and the pulse discharge characteristics after storage are summarized in Table 1 below. The internal resistance (1KHz AC method) and total height are room temperature (23 ° C).
It is the value measured under the environment. Also, the pulse discharge is −
When the load current value is 10 mA in a 20 ° C. environment,
It is the value of the battery voltage after 1 second.

In the above-mentioned Examples and Comparative Examples, lithium metal was used as the negative electrode active material, but it is not limited to this, and lithium-aluminum alloy, other lithium alloys, and carbon capable of occluding and releasing lithium ions. Materials and the like can also be used.

Further, a mixed solvent of propylene carbonate and diethylene glycol dimethyl ether was used as a solvent of the electrolytic solution, but the present invention is not limited to this, and ethylene carbonate, propylene carbonate, butylene carbonate, vinylene carbonate, cyclopentacarbonate Non-, sulfolane, 3-methylsulfolane, 2,4-dimethylsulfolane, 3-methyl-1,
3-oxazolidin-2-one, γ-butyrolactone,
Dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, methyl propyl carbonate, butyl methyl carbonate, ethyl propyl carbonate, butyl ethyl carbonate, dipropyl carbonate, 1,2-dimethoxyethane, tetrahydrofuran,
It is also possible to use simple substances such as 2-methyltetrahydrofuran, 1,3-dioxolane, methyl acetate and ethyl acetate, and binary and ternary mixtures.

Lithium perchlorate was used as the electrolyte, but LiPF ₆ , LiBF ₄ , LiCF ₃ S was used.
_{O 3, LiAsF 6, LiN (} CF 3 SO 2) 2, Li
_{OSO 2 (CF 2) 3 CF} 3 and the like can also be used.

[0027]

[Table 1]

[0028]

EFFECTS OF THE INVENTION From the results shown in Table 1, the pore diameter of 30Å-40
In the non-aqueous electrolyte batteries of Examples 1 to 3 of the present invention in which the pore volume of Å is 0.05 cc / g or less, it is possible to suppress gas generation under high temperature storage of 100 ° C. Prevents the battery from blistering and keeps 1.5V even after storage at high temperature.
It can be seen that high-current pulse discharge capable of holding the above voltage is possible.

[Brief description of drawings]

Fig. 1 Pore volume of pores with a pore size of 30Å-40Å is 0.01
Log differential pore volume distribution diagram of cc / g of manganese dioxide (desorption side).

[Figure 2] Pore volume of 30Å-40Å is 0.02
Log differential pore volume distribution diagram (desorption side) of 7 cc / g manganese dioxide and dilithium manganese trioxide composite.

[Fig. 3] Pore volume of 30Å to 40Å with a pore volume of 0.03
Log differential pore volume distribution diagram of 2 cc / g manganese dioxide (desorption side).

Fig. 4 Pore volume of 30Å to 40Å is 0.05.
Log differential pore volume distribution diagram of cc / g of manganese dioxide (desorption side).

FIG. 5: Pore volume of 30 Å to 40 Å with a pore size of 0.06
The log differential pore volume distribution diagram (desorption side) of manganese dioxide corresponding to the comparative example of cc / g.

Fig. 6 Pore volume of pores with a diameter of 30Å to 40Å is 0.12
The log differential pore volume distribution diagram (desorption side) of manganese dioxide corresponding to a comparative example of 5 cc / g.

FIG. 7 is a cross-sectional view of a non-aqueous electrolyte battery.

[Explanation of symbols]

1 ... Positive electrode plate 2 ... Positive electrode can 3 ... Separator 4 ... Gasket 5 ... Negative electrode plate 6 ... Negative electrode can 7 ... Current collector

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masahiro Imanishi             2-5-3 Keihan Hondori, Moriguchi City, Osaka Prefecture             Within Yo Denki Co., Ltd. (72) Inventor Nobuhiro Nishiguchi             2-5-3 Keihan Hondori, Moriguchi City, Osaka Prefecture             Within Yo Denki Co., Ltd. (72) Inventor Seiji Morita             2-5-3 Keihan Hondori, Moriguchi City, Osaka Prefecture             Within Yo Denki Co., Ltd. F-term (reference) 5H029 AJ07 AK03 AL06 AL12 AM03                       AM04 AM05 AM07 BJ03 BJ12                       CJ02 CJ08 DJ04 DJ16 HJ06                       HJ09                 5H050 AA10 BA17 CA05 CA09 CA29                       CB07 CB12 FA02 FA15 FA17                       GA02 GA10 HA06 HA09

Claims (3)

[Claims] 1. A non-aqueous electrolyte battery comprising a positive electrode having at least manganese dioxide or a composite of manganese dioxide and dilithium manganese trioxide as a positive electrode active material, a negative electrode, and a separator. Pore diameter is 30 ~ 4
A nonaqueous electrolyte battery having a pore volume in the range of 0Å of 0.05 cc / g or less. 2. The positive electrode active material has a pore size of 30Å-40
Pore volume in the range of Å is less than 0.05cc / g, 0.00
It is 5 cc / g or more, The non-aqueous electrolyte battery according to claim 1. 3. The positive electrode active material has a pore size of 30Å-40
Pore volume in the range of Å is less than 0.05cc / g, 0.01
It is cc / g or more, The non-aqueous electrolyte battery according to claim 2, which is characterized in that.