JPS6117104B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a negative electrode active material for a non-aqueous electrolytic battery using an organic electrolyte as an electrolyte.

Lithium has an extremely low standard electrode potential (−
3.045V vs. NHE), so if this is used as a negative electrode active material, high performance batteries with high energy density can be expected. However, because lithium easily reacts with air, nitrogen, and moisture, it is usually handled in an inert gas such as argon. However, this work requires an airtight glove box, which has the disadvantage of significantly lower work efficiency. Therefore, the lithium is processed while its surface is coated with liquid paraffin, carbon tetrachloride, petroleum ether, etc. in the same way as when storing lithium. Alternatively, it has been proposed to work in a liquid in which lithium does not react, for example in an organic electrolyte used as an electrolyte. However, these methods only involve a liquid between the lithium surface and the air, and the lithium surface is oxidized due to air and moisture dissolving in the liquid. has no resistance at all, and cannot be said to be sufficient in terms of protecting the lithium surface.

An object of the present invention is to provide a method for manufacturing a non-aqueous electrolyte battery that can be easily assembled and manufactured even in an air atmosphere. Place it in an inorganic solvent that is a liquid at the source, for example at 70-75℃ for 10
A passive film is formed on the surface of the lithium by heating for ~20 hours, and then after the negative electrode is formed, the film is removed using benzene before assembling the battery, thereby preventing lithium and air during handling of the negative electrode. It is characterized by easily and reliably preventing deterioration of battery performance due to the generation of oxides and hydroxides.

The present invention will be explained in more detail below using the drawings. FIG. 1 is a sectional view of a battery according to an embodiment of the present invention. In the figure, 1 is a positive electrode, which is made of a mixed powder of a positive electrode active material, carbon powder as a conductive agent, and a synthetic polymer material as a binder. On top of the positive electrode 1 is a separator 2 made of one or more layers of felt fibers, which is impregnated with and held with an organic electrolyte. On the separator 2 is a negative electrode 4 containing lithium as an active material. 5 and 6 are a negative electrode outer cover and a positive electrode container, respectively, and also serve as a negative electrode terminal and a positive electrode terminal, respectively. Both are made of highly corrosion-resistant metals such as stainless steel. Reference numeral 3 denotes an insulating gasket made of a material having electrolyte resistance, elasticity, and airtightness, such as nylon or polypropylene.

To obtain the battery of this example, first, a lithium piece press-molded on a nickel wire mesh in air was placed in a flask containing thionyl chloride (SOCl ₂ ) at 70°C to 75°C.
Heat for 10 to 20 hours. After that, the lithium piece is taken out and placed in dehydrated benzene to wash away the thionyl chloride attached to the lithium surface, yielding a negative electrode. The positive electrode was prepared by pressing a mixed powder of 10 parts manganese dioxide, 1 part acetylene black, and 1 part fluororesin onto a hackle wire mesh at a pressure of 1000 to 3000 kg/cm ² . The capacity of the battery is
It was set to 100mAh. The electrolyte is an organic electrolyte consisting of a solvent consisting of a mixture of propylene carbonate and tetrahydrofuran at a volume ratio of 7:3 and a solute of lithium perchlorate (LiClO ₄ ), and its concentration is 1 mol/l.
It is. This organic electrolyte was impregnated into a separator 2 made of polypropylene nonwoven fabric. The battery shown in FIG. 1 was assembled in air using each of the above members. This battery exhibits an open circuit voltage of 3.5 V, and its discharge characteristics when discharged at a current density of 1 mA/cm ² at room temperature are as shown in A in FIG. For comparison, the characteristics of a lithium/manganese dioxide battery B when assembled in an organic electrolyte according to the prior art and C when assembled in a glove box filled with argon are shown in FIG. 2, respectively.

According to FIG. 2, battery A according to the embodiment of the present invention exhibited better performance than battery B in terms of conventional techniques, and almost the same performance as battery C when using a glove box, which was significantly inferior in workability. Therefore, according to the present invention, an excellent high-performance organic electrolyte battery comparable to the conventional one can be obtained with simpler and more efficient operation than the conventional technique.

In the above example, thienyl chloride was used as the inorganic solvent, but it is also possible to use sulfuryl chloride (SO ₂ Cl ₂ ), phosphoryl chloride (POCl ₃ ), etc., and almost the same effect as in the above example can be obtained. can get.

According to the present invention, since the film is created using a liquid, the work is extremely simple compared to gases that require sealing, and a passive film can be reliably formed on the lithium surface. Moreover, since this coating is removed with benzene before being assembled into a battery, good battery performance can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a battery according to an embodiment of the present invention, and FIG.
The figure is a diagram showing a comparison of discharge characteristics between a battery A according to an embodiment of the present invention and batteries (B and C) according to the prior art. 1...Positive electrode, 2...Separator, 3...Gasket, 4...Negative electrode, 5...Negative electrode outer cover, 6...Positive electrode container.

Claims (1)

[Claims] 1. A positive electrode containing one selected from the group consisting of metal halides, metal chalcogenides, and metal oxyacids as an active material, an electrolytic solution consisting of an organic electrolyte in which inorganic salts of an organic solvent are dissolved, and lithium as an active material. In the manufacturing method of a non-aqueous electrolyte battery consisting of a negative electrode, lithium is press-molded onto a nickel wire mesh in air and placed in a liquid inorganic solvent at room temperature and pressure, and then heated to form an inorganic material on the surface of the lithium. After making the dynamic film and then molding the negative electrode,
A method for manufacturing a non-aqueous electrolyte battery, which comprises removing the film using benzene and then assembling the battery together with a positive electrode and an electrolyte.