JPH0227662A - Nonaqueous electrolyte battery - Google Patents

Abstract

PURPOSE:To improve the discharge characteristic after storage by providing a negative electrode using lithium or lithium alloy as an active material, a positive electrode using manganese dioxide as an active material, and a specific liquid organic electrolyte. CONSTITUTION:In a nonaqueous electrolyte battery constituted of a negative electrode using lithium or lithium alloy as an active material, a positive electrode using manganese dioxide as an active material, and a liquid organic electrolyte, an electrolyte solved with lithium trifluoromethane sulfonate in a mixed solvent of gamma-butyrolactone and dimethoxyethane is used for the liquid organic electrolyte. The discharge characteristic of a lithium-manganese dioxide nonaqueous electrolyte battery after storage is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a nonaqueous electrolyte battery comprising a negative electrode using lithium or a lithium alloy as an active material, a positive electrode using manganese dioxide as an active material, and a liquid organic electrolyte. It is something.

Conventional Technology Various materials have been proposed as positive electrode active materials for non-aqueous electrolyte batteries, including metal oxides, sulfides, and chlorides. Among these, manganese dioxide is particularly economical due to its low price and has already been used. It has been put into practical use.

Regarding the electrolyte, propylene carbonate (PC) and dimethoxyethane (DME) are used as solvents.

Lithium perchlorate (L) as a solute is added to γ-butyrolactone (GBL), tetrahydrofuran (THF), etc.
i(JO4), lithium borofluoride (I, 1BF4)
Lithium trifluoromethanesulfonate (LiCF,
So, etc. have been proposed.

In a non-aqueous electrolyte battery using manganese dioxide as a positive electrode active material, lithium trifluoromethanesulfonate is dissolved in propylene carbonate and dimethoxyethane as disclosed in JP-A-67-43364 as a non-aqueous electrolyte for efficient operation of the positive electrode. A liquid organic electrolyte has been proposed and is actually used.

Problems to be Solved by the Invention In the case of the organic electrolyte disclosed in JP-A-57-43364, there was a problem with the discharge characteristics after storage. In recent years, non-aqueous electrolyte batteries have become rapidly popular due to their high voltage and high energy density, and as a result, there has been a demand for improvements in the discharge characteristics of this type of batteries after storage.

Means for Solving the Problem In order to solve this problem, the present invention provides a non-aqueous electrolyte comprising a negative electrode using lithium or a lithium alloy as an active material, a positive electrode using manganese dioxide as an active material, and a liquid organic electrolyte. The electrolyte battery uses an electrolyte formed by dissolving lithium trifluoromethanesulfonate in a mixed solvent of γ-butyrolactone and dimethoxyethane as a liquid organic electrolyte.

Effect: According to this configuration, the discharge characteristics of the lithium-manganese dioxide nonaqueous electrolyte battery after storage can be improved.

The reason for this is not clear, but it is thought to be due to the synergistic effect of γ-butyrolactone and lithium trifluoromethanesulfonate.Example: An example of the present invention will be described in detail below.A lithium rolled plate was cut into predetermined dimensions as a negative electrode. Also, manganese dioxide (active material), carbon powder (conductive agent), and fluororesin powder (binder) were used as the positive electrode.
After mixing at a weight ratio of s, this mixture was molded and heat treated.

A cylindrical nonaqueous electrolyte battery was assembled using the above positive and negative electrodes, a separator made of a nonwoven polypropylene fabric, and a nonaqueous electrolyte having the composition shown in the table below.

Note that the solvent used was a mixture of equal volume ratios.Battery systems using non-aqueous electrolytes a and b shown in the above table, respectively.

Figure 1 shows the discharge characteristics of B after being stored at room temperature for 2 years. The discharge conditions were continuous pulse discharge with a constant current of 90C at +20'C and a cycle of ON for 3 seconds and OFF for 27 seconds. As is clear from these results, it can be seen that the battery of the present invention has superior discharge characteristics after storage compared to battery B. Note that the discharge characteristics of battery B after storage for one week at room temperature are the same. Furthermore, regarding safety, the test results for both batteries were equivalent.

Effects of the Invention As mentioned above, the battery of the present invention exhibits excellent discharge characteristics after storage, especially non-aqueous electrolyte batteries using lithium or lithium alloy as the negative electrode active material and manganese dioxide as the positive electrode active material. , its industrial value is extremely limited.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the discharge characteristics of the battery of the present invention after being stored for two years at room temperature. Dotted line: Discharge characteristics after one week of storage at room temperature, solid line: Discharge characteristics after two years of storage at room temperature. Name of agent: Patent attorney Shigetaka Awano and 1 other person 1st
Figure 5θθ 10ρ0 15θθ group Denjo Okuru (turning)

Claims (1)

[Claims] A non-containing electrolyte comprising a negative electrode using lithium or a lithium alloy as an active material, a positive electrode using manganese dioxide as an active material, and a liquid organic electrolyte formed by dissolving lithium trifluoromethanesulfonate in a mixed solvent of γ-butyrolactone and dimethoxyethane. Water electrolyte battery.