JPS59180965A - Nonaqueous solvent battery - Google Patents

Abstract

PURPOSE:To realize high rate discharge while maintaining high temperature storage characteristic by employing S or P oxyhalide as positive pole active substance and electrolyte while a piece of cloth made of C2-3 alkylene polymer fiber and glass fiber as a separator. CONSTITUTION:A negative stripe electrode 4 made of light metal and a positive stripe electrode 5 made of porous carbon sheet layer are wound spirally through a separator 6 to produce an electrode group 2 which is contained in a can 1. While electrolyte employing S or P oxyhalide as main positive pole active substance is contained in the can 1 and impregnated in the separator 6. Here said separator 6 is formed with a piece of cloth or unwoven cloth where more than one kind of polyethylene, polypropylene, ethylene-propylene copolymer macromolecular fiber and glass fiber are mixed. Said separator 6 has excellent thermal stability, liquid holdability and liquid absorbability, high workability and enable of high density resulting in high rate discharge of nonaqueous solvent battery.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a non-aqueous solvent battery, and more particularly to a non-aqueous solvent battery with an improved separator.

[Technical background of the invention and its problems]

Nonaqueous solvent batteries that use lithium and sodium as negative electrode active materials have high energy density, excellent storage characteristics, and a wide operating temperature range.
It is often used as a backup power source for memory. Among them, lithium was used for the negative electrode, and thionyl chloride (5ocz, ) and sulfuryl chloride (SO2C) were used as the positive electrode active material.
22), batteries using sulfur or phosphorus oxyhalides such as phosphoryl chloride (Poct3) have attracted attention in recent years because of their particularly high energy density. These cells have a positive electrode derived from a carbon and metal current collector and are typically made of Lewis acids such as aluminum chloride (p,tCt3), aluminum bromide (AtBr3) and lithium chloride (LiC).
A) An oxynologenide of sulfur or phosphorus in which a Lewis base such as lithium bromide (LiBr) is dissolved is used as an electrolyte. Therefore, the oxyno-loginide serves both as a positive electrode active material and as an electrolyte, and by using a positive electrode with an appropriate shape, a battery with excellent high rate discharge characteristics can be obtained.

In the above-mentioned non-aqueous solvent battery, a separator/e-lator is used to isolate the positive electrode and the negative electrode and to hold the electrolyte, but there are many restrictions on the material of the separator. That is, the material must not react with battery constituent materials such as the positive electrode, negative electrode, electrolyte, etc., and must be mechanically strong. In addition, it is required that the electrolyte absorption rate be fast, that the electrolyte be retained well, and that there be no defective parts that could cause internal short circuits in the battery. Furthermore, with the recent expansion of applications, the temperature inside the battery often rises, such as when batteries are used in high-temperature locations such as automobiles, or when used in high-power equipment to discharge large currents, so separators are required to be heat-resistant. It is now necessary to have both gender.

By the way, as a cenogrator that can be incorporated into a conventional non-aqueous solvent battery, one made of a woven or non-woven fabric made of glass phytsmer is used. A separator made of such a woven or nonwoven glass fiber fabric is thermally strong, and the glass fibers themselves can be made thinner, so they have excellent electrolyte retention properties. However, glass fibers are difficult to weld and have poor workability, and a separator made of glass fibers has a low density, so if the film is made thinner to achieve high rate discharge, its storage properties will deteriorate. There was a drawback.

On the other hand, polyethylene is also used in non-aqueous solvent batteries.

Separators made of sheets of polypropylene, ethylene-propylene copolymer, or polyethylene-polypropylene composite are used.

However, polyethylene is 80-120°C.

Since polypropylene deforms and melts at temperatures of 90 to 140° C., it is problematic to incorporate a semi-quartet made of such a polymer material into a non-aqueous solvent battery for use as described above.

[Purpose of the invention]

The present invention aims to provide a non-aqueous solvent battery equipped with a separator that has excellent thermal stability, liquid retention, and liquid absorption, has good processability, and can be made to have a high density.

[Summary of the invention]

In the present invention, a negative electrode and a positive electrode made of a light metal are installed in a can via a cell, and an electrolytic solution containing sulfur or phosphorus oxynologenide as the main positive electrode active material is placed inside the can. In the housed one IP water solvent battery, a woven fabric or non-woven fabric 75 in which a polymer fiber made of at least one of polyethylene holiflopylene and an ethylene-propylene copolymer and glass fiber are mixed is used as the 7-9 polymer. It is characterized in that it uses a material formed from scratch.

Such separators have thermal stability due to glass fibers,
It has liquid retention and absorption properties, excellent processability due to the mixture of polymer fibers, flexibility, and complete crushability. Moreover, since the separator is a mixture of glass fiber and highly flexible polymer fiber, it has a high density (0.23 to 0.289
7cm3) is possible. Therefore, power, force)
Since the pv-ta can be used in a thin film state, it prevents short circuits between the positive and negative electrodes during storage at high temperatures. can be easily assembled.

The thickness of the polymer fibers is preferably in the range of 20 to 50 μm from the viewpoint of further improving the density of the separator. Regarding the thickness of glass fiber, 01~
It may be within the range of 2 μm.

The mixing ratio of the above polymer fiber and glass fiber is 3 polymer fibers.
It is desirable that the glass fiber content be in the range of 0 to 70% by weight and 70 to 30% by weight of glass fiber. The reason for this is that if the mixed ratio of polymer fibers is less than 30% by weight, not only will the processability not be sufficiently improved, but it will also be difficult to achieve a sufficiently high density. This is because there is a risk that the amount of glass fiber will be insufficient and the thermal stability, liquid absorbency, etc. will be impaired.

[Embodiments of the invention]

Next, embodiments of the present invention will be described with reference to the drawings.

The figure shows a D-size spiral-shaped lithium-thionyl chloride battery, and 1 is a can made of, for example, stainless steel, which also serves as a negative electrode terminal. Inside this can body l, a spiral electrode group thread is inserted into the complementary insulating material 3.
It is stored through. This electrode group Z includes a laminated structure in which a separator 6 is interposed between a strip-shaped negative electrode 4 and a strip-shaped positive electrode 5.

It is wound in a spiral shape so that the strip-shaped positive electrode 5 is exposed on the outside.

The strip-shaped negative electrode 4 is made by, for example, pressing a commercially available metal lithium thin plate onto a nickel mesh (metal current collector). The positive electrode 5 is made by forming a sheet of a commercially available mixture of acetylene black, polytetrafluoroethylene (binder), and ethyl alcohol, pressing it onto a stainless steel net (metal current collector), and then heating and drying it. NI is made by forming the sheet material into a porous carbon layer.

The separator 6 is made of polypropylene fibers 60 with a thickness of 20 to 30 μm and glass fibers 4 with a thickness of 0.3 to 1 μm.
Thickness 02 scale, density 0.25 with 0 weight bun mixed? /
It is made of LOM3 nonwoven fabric. The separator 6 is impregnated with, for example, 1.5 mol//l of thionine chloride (electrolytic solution) in which L 1Al-C24 is dissolved.

A cylindrical insulating material 7 similar to the separator 6 is provided on the strip-shaped positive electrode 5 inside the spiral electrode groups.

The metal current collector of the strip-shaped negative electrode 4 of the electrode group thread is connected to the can body 1 via a lead wire 8.

Further, a disk-shaped sealing plate 9 made of plastic is airtightly provided at the upper opening of the can body 1. A hole 10 is opened in the center of the sealing plate 9, and a ring-shaped groove 11 is formed concentrically with the hole 10 on the upper surface thereof. In addition, a gas vent hole 12 is formed in a part of the ring-shaped groove 1 to vertically penetrate the sealing plate 9. A positive electrode terminal 13 is attached to the sealing plate 9. This positive electrode terminal 13 is connected to a metal disc 15 disposed on the sealing plate 9 via an O cylinder (safety valve) 14 fitted in the ring-shaped groove 11, and passes through this disc 15 to A rivet 16 for suppressing and fixing the disc 15 inserted into the hole 1θ of the sealing plate 9, and a lead connection piece 17 caulked to a portion of the rivet 16 protruding from the lower surface of the sealing plate 9. It is configured. Front = HOIJ tongue 4 is pushed upward by the gas pressure from the gas vent hole 12 when the internal pressure of the can body 1 rises above a predetermined pressure. ．． It escapes through the ring-shaped groove 11 and serves to prevent the battery from exploding. Further, the lead connection pieces 17 are connected to the metal current collectors of the strip-shaped positive electrodes 5 of the electrode groups through lead wires 18.

Comparative Example 1 A lithium-thionyl chloride battery was produced with the same structure as described above, except that a nonwoven fabric (density 0.297♂) of the same thickness as in the example was used as a separator made of glass fiber with a thickness of 03 to 1 μm.

Comparative Example 2 A separator made of a nonwoven fabric (density 0.31-30 μm) with the same thickness as in the example, made of polyethylene fibers with a thickness of 20 to 30 μm.
Lithium with the same structure as above except that /1yn3) was used.
A thionyl chloride battery was fabricated.

Comparative Example 3 As a separator, a nonwoven fabric (density 0.311
A thium-thionyl chloride battery was produced using the same mb'2 glue as above, except that 7 cm 3) was used.

After fabrication, the four types of batteries were subjected to constant current observation at 5 A for 5 minutes every 5 hours in an atmosphere at 60° C. to examine their discharge capacities (storage characteristics). The results are shown in the table below.

As is clear from the table above, it can be seen that the non-inventive battery has superior high-rate discharge characteristics at high temperatures compared to conventional batteries.

The reason for the difference in discharge characteristics between the battery of the present invention and the conventional battery is as follows. That is, when a large current discharge such as 5A discharge is performed, if the separator of Comparative Example 1 has a low density of 0.297 cm3 and is made of a thin glass fiber nonwoven fabric, the positive electrode isolated by the separator - A slight short circuit occurs between the negative electrodes, resulting in a decrease in discharge capacity.

Further, when a large current discharge is performed, local heating occurs within the battery, and the separator in that area becomes abnormally heated. Therefore, in batteries (Comparative Examples 2 and 3) using a separator made of a single nonwoven fabric of polyethylene fibers or polypropylene fibers, the heated portion of the separator deteriorates and causes a slight short circuit, resulting in a decrease in discharge capacity. . In contrast, the separator used in the battery of the present invention has a density of 0.
．． Since the film is as high as 24M%, it is possible to sufficiently isolate the positive and negative electrodes during large current discharge even if the film is made thinner.
Slight short circuits between negative electrodes can be suppressed. In addition, since the Nana-R Rator contains glass fiber with excellent heat resistance, it is possible to avoid deterioration of the Nana-E Rator due to local heating during large current discharge, and to prevent the occurrence of minute short circuits. It can be suppressed. Therefore, according to the battery of the present invention, a decrease in discharge capacity due to a slight short circuit can be prevented.

"In the above embodiment, a spiral electrode group with a separator interposed was used as the negative electrode and the positive electrode, but the invention is not limited to this. For example, a cylindrical negative electrode is crimped to the inner surface of the can, and A structure may be adopted in which a positive electrode made of a cylindrical porous carbon body with a metal current collector crimped onto the inner peripheral surface of the can is housed with a separator interposed therebetween.

〔Effect of the invention〕

As detailed above, the present invention includes a separator that has excellent thermal stability, liquid retention, and liquid absorption, has good processability, and can be made highly dense, and has excellent storage characteristics at high temperatures. It is possible to provide an easy-to-manufacture non-aqueous solvent battery that can achieve high rate discharge while maintaining the same.

[Brief explanation of the drawing]

The figure is a cross-sectional view showing a D-size spiral-shaped lithium-thionyl chloride battery showing one embodiment of the present invention. 1. Can body, consideration... spiral electrode group, 4... elbow-shaped negative ridge, 5... strip-shaped positive electrode, 6... separator, 9...
Sealing plate, 12... gas vent hole, 1.9 = positive electrode terminal,
14...0 ring (safety valve), 16...Rivet. Applicant's representative Patent attorney Takehiko Suzue 3-4-10, Minamishinayo, Tokyo Parts Ward Toshiba Battery Co., Ltd. 0 Applicant Toshiba Battery Co., Ltd. 3-4-10 Minamishinayo, Tokyo Parts Ward

Claims (1)

[Claims] In a non-aqueous solvent battery, in which a negative electrode and a positive electrode made of a light metal are provided in a can via a carbon dioxide lake, and an electrolytic solution containing sulfur or phosphorus oxyno-10 as the main positive electrode active material is housed in the can. , a nonaqueous solvent battery characterized in that the separator is selected from polyethylene, polypropylene, and ethylene-propylene copolymer 1.