JPS6023972A - Positive electrode for nonaqueous solvent battery - Google Patents

Abstract

PURPOSE:To obtain a nonaqueous solvent battery having an excellent ability of electrochemically reducing thionyl chloride and causing little deterioration of its electrochemically reducing ability even after stored for a long period or at high temperature by packing a positive base member with a specific metal complex. CONSTITUTION:In a nonaqueous solvent battery containing a negative electrode consisting of an alkali metal and electrolyte principally consisting of thionyl chloride also serving as a positive active material, a positive electrode is made by packing a positive base member such as a porous carbon body with a tetraazaannulene metal complex (M-TAA) represented by the general formula in which M preferably represents Co, Fe, Ni, Mn or Cu. The thus obtained positive electrode for a nonaqueous solvent battery has a high electrochemically reducing ability, causes little deterioration of its activity even after stored for a long period or at high temperature and has a low cost. Co-TAA can most favorably be used as the above M-TAA because it has the highest durability and catalytic activity. In addition, it is desirable that the ratio by weight of M-TAA packed in the positive base member to the positive base member be in the range of 1-10%.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to improvements in positive electrodes used in non-aqueous batteries.

[Technical background of the invention and its problems]

In recent years, lithium-thionyl chloride-based nonaqueous solvent batteries have attracted attention as batteries with high energy density, long-term storage characteristics, and a wide operating temperature range. The biggest feature of this battery is that thionyl chloride is used as the positive electrode active material, and the stain pond reaction progresses as the thionyl chloride is electrochemically reduced on the surface of the positive electrode, which is mainly composed of porous carbon. do.

By the way, a general cylindrical lithium-thionyl chloride battery has a lithium negative electrode arranged inside the can, and a porous carbon body with a metal current collector such as a wire mesh inside the can inside the negative electrode. The structure is such that the cathode is impregnated with an electrolyte containing thionyl chloride that also serves as a cathode active material. The porous carbon body which is a constituent material of this positive electrode is prepared by adding a binder such as polytetrafluoroethylene to curd black such as acetylene black, molding the mixture, and drying the mixture.

Among the properties required of the porous carbon body of the positive electrode described above, the most important characteristic is the activity for the electrochemical reduction reaction of thionyl chloride.

Among the many carbonaceous materials, acetylene black has the highest activity, but recently it has been possible to further increase the activity by supporting noble metals such as platinum or metal complexes such as phthalocyanine on porous carbon materials as electrode catalysts. It has been reported that.

However, noble metals such as platinum, radium, and rhodium are expensive, leading to an increase in battery costs. Furthermore, although the metal complex catalysts proposed so far are relatively inexpensive, they have the disadvantage that their catalytic activity deteriorates during storage for long periods of time or at high temperatures.

[Purpose of the invention]

The present invention has an excellent electrochemical reduction ability with thionyl chloride, and does not exhibit inferior electrochemical reduction ability even after storage for a long period of time or at high temperatures.
The aim is to provide the following:

[Summary of the invention]

The present inventors have proposed a positive electrode for use in a non-aqueous battery comprising a negative electrode made of an alkaline compound and an electrolytic solution containing thionyl chloride, which also serves as a positive electrode active material. is Co, Fe, Ni, Mn
, Cu tetraazaannulene metal complex (hereinafter referred to as M-
By supporting TAA (M is abbreviated as metal) on a positive electrode such as a porous carbon body, the electrochemical reduction ability (activity) is high as described above, and even after storage for a long period of time or at high temperature. We have discovered an inexpensive positive electrode for non-aqueous batteries with little deterioration in activity.

Among the above M-TAAOs, Co-TAA is advantageous because it has the best durability and melting medium activity.

The amount of M-TAA supported on the positive electrode substrate is usually 1 to 1.
A range of 0% by weight is desirable.

[Embodiments of the invention]

Next, the present invention will be explained in detail.

Example 1 t f , Co-TAA 0.5 E in tetrahydrofuran 1! After dissolving the acetylene in this solution,
10 g of black was dispersed and thoroughly stirred, and further tetrahydro7ran was evaporated. Next, 10% by weight of a water-soluble ice version of polytetrafluoroethylene was added to the acetylene black supporting Co-TAA.
Knead to form a strip, which is then molded into a nickel net (40
After spreading it on both sides of the mesh, it was dried at 150°C for 12 hours to form a sheet-like positive electrode (15W x 30L x 05twn).
) was created.

A lithium-thionyl chloride battery was constructed using the sheet-like positive electrode. The battery configuration consists of a lithium negative electrode (15w x 30L x 0°7'am) crimped onto a nickel mesh.
) The sheet-like positive electrodes were made to face each other through a K f lath fiber nonwoven fabric (thickness: 0.3rnFn) to form a sandwich-like electrode group, which was immersed in a 1.8M LiCbAtC15 thionyl chloride' electrolyte, and then placed in a glass container. It has a sealed structure.

Examples 2 to 5 Fe-TAA, Mn-TAA, instead of Co-TAA
Cu-TAA.

A positive electrode similar to that in Example 1 except that N1-TAA was used was prepared, and four types of lithium-ion with the same configuration as in Example 1 were prepared using these positive electrodes.
A thionyl chloride battery was assembled.

Comparative Example A positive electrode having the same composition and shape as in Example 1 was prepared except that Co-TAA was not supported, and thereby a lithium-thionyl chloride battery having the same structure as in Example 1 was assembled.

Therefore, regarding the batteries of Examples 1 to 5 and Comparative Example,
The initial discharge capacity (2.5 V final voltage) was investigated by changing the discharge current density. The results are shown in Table 1 below. -1: The discharge capacity at 5 mA/i discharge (2.5 V end voltage) was investigated over the number of days during storage at 60°C. The results are shown in Table 2 below.

Table 1 Table 2 As is clear from Table 1 and Table 2 above, the Co of the present invention
-TAA, Fe-TAA, Mn-TAA, Cu-
A battery using a positive electrode made of a gold-H complex of TAA or N1-TAA supported on a porous carbon body has a higher discharge capacity than a conventional battery using a positive electrode made of a two-porous carbon body without supporting metal lead. It can be seen that the battery using a positive electrode in which Co-TAA is supported in a porous carbon body has particularly excellent initial discharge capacity and discharge capacity after long-term high-temperature storage.

In the above embodiments, a porous carbon body containing acetylene black as a main phase was used as the positive electrode base material, but the present invention is not limited thereto. For example, a car other than acetylene black? porous carbon bodies made of plastic, foamed metals, metal oxides,
A similar effect can be achieved by using a material with good electrical conductivity such as a metal sulfide or a conductive polymer material as the positive electrode base material.

〔Effect of the invention〕

As detailed above, the positive electrode for nonaqueous solvent batteries according to the present invention has excellent electrochemical reduction ability between the positive electrode active material and thionyl chloride, which also serves as the electrolyte, and even after storage for a long period of time or at high temperatures. It has a function with little deterioration of the ability,
By using this positive electrode, the capacity deterioration rate is small even when stored at high temperatures, and an inexpensive non-aqueous solvent battery with excellent high rate discharge characteristics can be obtained.

Applicant's representative Patent attorney Suzue Takehiko Tokyo Shibaura Electric Co., Ltd. General Research Laboratory, 1 Komukai Toshiba-cho, Saiwai-ku, Yosaki City @Applicant: Toshiba Battery Co., Ltd., 3-4-10 Minamishinayo, Tokyo Parts Ward

Claims (3)

[Claims] (1) In a positive electrode used in a non-aqueous battery comprising a negative electrode made of an alkali metal and an electrolyte containing thionyl chloride as the main positive electrode active material, the general formula [where M in the formula is Car Fe, Nr] , Mn,
1. A positive electrode for a non-aqueous solvent 1a pond, characterized in that a tetraazaannulene metal complex represented by [Cu] is supported on a base layer of 1η. (2) The positive electrode for a non-aqueous solvent battery according to claim 1, wherein M in the general formula is Co as the tetraazaannulene metal complex. (3) Claim 1, characterized in that the positive electrode base material is a porous carbon body containing acetylene black as a paste.
A positive electrode for a non-aqueous solvent battery as described in .