JPS6012744B2 - battery - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a battery using an iodine-added charge transfer complex having a quaternary ammonium group as a positive electrode active material and lithium as a negative electrode active material.

Conventional batteries using active light metals such as lithium, sodium, and magnesium as negative electrode active materials include those that use liquid electrolytes and those that use solid electrolytes.

In batteries that use liquid electrolytes, organic solvents such as propylene carbonate, tetrahydrofuran, and y-butyrolactone are combined with lithium perchlorate, lithium borofluoride,
An electrolyte in which potassium hexafluorophosphate or the like is dissolved as a supporting electrolyte is used, and the positive electrode active material is a metal compound such as steel fluoride, nickel chloride, nickel fluoride, silver fluoride, silver chromate, or carbon fluoride. etc. are used, and generally have a structure as shown in FIG. That is, the positive electrode 13 is formed by mixing the above-mentioned active material with a conductive material such as carbon powder and a suitable binder, and press-molding the mixture around a current collector 14 such as a nickel mesh or a titanium mesh.

The negative electrode 15 is constructed by press-fitting a current collector 16 such as nickel mesh or stainless steel silk into a light metal such as lithium, and the positive and negative electrodes are formed by enclosing a separator 17 such as polypropylene and the electrolyte 18 in a battery case 6. This battery is constructed.
19 is a negative electrode lead welded to the dew tank 6, 20 is a positive electrode terminal provided insulated on the sealing plate 7, and 21 and 22 are insulating plates.
On the other hand, batteries using solid electrolytes include lithium iodide as the electrolyte and solid charge transfer complexes such as berylene iodide and poly(4-vinylpyridine iodide) as the positive electrode active material. One known uses a paste-like charge transfer anchor in which a cyclic compound with an electron cloud is used as an electron donor and iodine is used as an electron acceptor.
The structure of this battery is relatively simple as shown in FIG. That is, the positive electrode 23 is formed by molding solid berylene iodide around a titanium mesh 24, and the negative electrode 25 is formed by press-fitting stainless steel silk 26 into lithium in the same manner as described above. Then, both electrodes are inserted into the turtle tank 6 together with the lithium bodide layer 27 inserted between them, and the empty space inside the tank is filled with a sealing material 28 such as epoxy resin to maintain airtightness. be done. 29 and 30 are a positive terminal and a negative terminal attached to the sealing plate 7 in an insulated manner.

As described above, a battery using a liquid electrolyte has the disadvantage that its structure is complicated.

Also, since the electrolyte is a liquid, when the external temperature becomes low,
This has the disadvantage that the viscosity of the electrolyte changes and the ionic conductivity decreases, resulting in a significant decrease in battery characteristics. On the other hand, batteries using solid electrolytes have a relatively simple structure;
Unlike liquid electrolytes, battery characteristics are not significantly affected by external temperature. However, since the ion movement speed of the collective electrolyte is originally extremely slow, the discharge current is extremely small.Furthermore, as the solid electrolyte (lithium chloride) layer increases with discharge, the discharge pressure increases due to the increase in internal resistance. It has the disadvantage of gradually decreasing. Therefore, the uses of batteries were also limited. In addition, batteries using the liquid electrolyte have a low energy density per unit volume, that is, about 1 to 2 ferradii per mole of the positive electrode active material itself, and this decreases further with the addition of conductive materials. . As described above, conventional batteries of this type have various problems.

The present invention provides an excellent battery that has a relatively simple structure, a high energy density, and a wide operating temperature range.

That is, the present invention uses lithium as a negative electrode active material, an iodine-added charge transfer body having a quaternary ammonium group as a positive electrode active material, and an electrolyte layer formed by a reaction between lithium and the iodine-added charge transfer body. It is characterized by using a solid electrolyte.

Therefore, according to the present invention, metal lithium and the anchor may be reacted to form an electrolyte layer separate from the positive and negative electrodes, and this may be combined with the positive and negative electrodes to form a battery.
By bringing the lithium negative electrode into contact with the active material of the positive electrode, an electrolyte layer can be formed on the surface of the negative electrode, making it extremely easy to assemble the battery.

It is surprising that a battery can be constructed by bringing the positive and negative electrodes into contact in this way, but the present inventors have discovered that a solid electrolyte with excellent lithium ioconductivity is produced by the reaction between lithium and the complex, and the key They discovered that it is possible to obtain a high-energy-density solid electrolyte battery that utilizes the discharge of iodine in the body.

Note that it is particularly advantageous to use a material that is liquid at room temperature as the collar body.

The present invention will be explained below with reference to Examples.

FIG. 1 shows an example of the battery configuration of the present invention.

In the figure, 1 is a positive electrode active material, 2 is a current collector made of nickel mesh, stainless steel silk, etc. that is in contact with the positive electrode active material, and is in contact with the battery case 6. The positive electrode active material is an iodine-added charge transfer ring having a quaternary ammonium group, and this ring is liquid at room temperature and has good electronic conductivity, so it cannot collect current at a discharge rate of several mA/. Body 2 is not required. For the purpose of high rate discharge, a current collector 2 may be provided or an inert conductive material such as carbon powder may be added. Reference numeral 3 denotes a negative electrode made of lithium metal, into which a current collector 4 of nickel mesh, stainless steel silk, etc. is press-fitted.

When this negative electrode is inserted into the positive electrode active material 1, a thin film electrolyte layer 5 of lithium iodide is formed on its surface. Numeral 7 is a sealing plate made of stainless steel like the dew tank 6, and a negative electrode terminal 9 is provided in the center thereof in an airtight manner and insulated from the sealing plate 7 by a glass 8.

10' is an insulating plate, and 11 is a sealing material such as epoxy resin filled in the upper part thereof.

The dew tank 6 and the sealing plate 7 are airtightly connected by welding. In this battery, since the electrolyte layer 5 formed as described above is thin, a high rate of discharge that could not be achieved with conventional batteries using solid electrolytes is possible.

Additionally, lithium chloride is produced during discharge, but this precipitates within the liquid cathode active material layer, and the electrolyte layer always exists at a constant thickness, so the internal resistance of the battery hardly increases. There is. It is also possible to further improve the high rate discharge characteristics by adding, for example, y-butyrolactone to the positive electrode active material as a lithium iodide supplement. Next, the positive electrode active material used in the present invention will be explained.

This active material is a charge transfer anchor R formed from quaternary alkyl ammonium iodine RN-1 and iodine-12.
N·k (×>1), and can be obtained by mixing various alkylammonium iodides and iodine, examples of which will be given later. m N-methylpyridinium iodide [
CH3-N+D]・- [2' N-ethylpyridinium iodide '3'
N-n hexylpyridinium iodide {4) N-methyl-4-methylpyridinium iodide [5) N
-Methyl-4-ethylpyridinium iodide '6'
N-methyl-4-cyanopyridinium iodide'
7) N-Butyl-4-cyanopyridinium iodide [8} N-methyl-4-phenylpyridinium iodide '91 N-methyl-Q-picolinium iodide OQ N-methyl-3-picolinium iodide OU N-methyl-3.5 rutidinium iodide 02 N-methyl-2,6-rutidinium iodide 03 N-methyl-2,4-rutidinium iodide 0 cores N-methylpyrimidium iodide 03 N
-Methyl-2-methylpyrimidium iodide 06)
N-methylpyrazinium iodide 0? ) N-methyl-2-methylpyrazinium iodide 08) N-
Methyl-2-ethylpyrazinium iodide■ N-
Methylquinolinium iodide N-ethylquinolinium iodide GU N-methyl-2-methylquinolinium iodide G2 N-ethyl-2-methylquinolinium iodide ■ N・N'-dimethylphenazinium iodide Died leg N-Methyl piberidinium iodide G3 1-Methyl-2H-pyrrolinium iodide ■1-Methyl pyrrolinium iodide leg 1-Methyl imidazo IJum iodide Sasamu N-
Methylbenzoylpyridinium iodide■ N-ethylbenzoylpyridinium iodide■ N-heptylbenzoylpyridinium iodide GI) N-
Methylsonicotinic acid methylester iodide 82
N-ethylisonicotinic acid methyl ester iodide G3 N-methylisonicotinic acid ester iodide N-ethyl isonicotinic acid ethyl ester iodide aside from acetylcholine iodide these alkylammonium iodides can be obtained by The charge transfer anchor is a liquid at room temperature, and its electronic conductivity hardly changes even at around -30 oo, about 4
It becomes solid near 0qo and its conductivity decreases slightly.

Therefore, the battery fin bending is hardly affected by the external temperature. These keys can also contain large amounts of iodine. For example, a collar using N-methylpyridinium iodide may contain 10 moles of iodine per mole of this compound. Therefore, it becomes a positive electrode active material with high energy density. The discharge reaction of a battery using total RN1x as a positive electrode active material and lithium as a negative electrode active material is expressed as follows. Positive electrode reaction & 10 → 21 - Negative electrode reaction 2Li → 2Li++ to overall battery reaction Z14i → 4il In order to further increase the energy density in this battery system, a structure as shown in Figure 2 can be explored.

That is, by adding an excess of solid iodine 12 to the haze tank 6, the iodine ions consumed by discharge are compensated for by replenishing the solid iodine into the collar body of the positive electrode active material. In addition, in order to improve the ionic conductivity of the lithium chloride thin film layer of the solid electrolyte, by adding a divalent metal such as calcium to the negative electrode or using a lithium-calcium alloy, the resulting electrolyte can be converted into calcium lithium chloride. It can improve ionic conductivity and enable high rate discharge.

Figure 3 shows lithium as the negative electrode active material and 10 iodine per mole of N-methylpyridinium iodide as the positive electrode active material.
2 shows the current-voltage characteristics of a battery using a charge transfer collar formed by adding moles.

This battery exhibited a barrier voltage of 2.80 V, and almost no change in characteristics was observed at temperatures of 50 to 125 degrees. In addition, almost the same characteristics as above were obtained using a charge transfer body using the above-mentioned compounds as an active material. Note that it is also possible to add chlorine and bromine at the same time when generating the charge transfer body.

As described above, the battery of the present invention has an extremely simple battery structure and is easy to manufacture.

Furthermore, the energy density is high, and the energy density can be selected relatively easily by changing the amount of iodine added. Furthermore, it has features such as a wide operating temperature range and particularly excellent characteristics at low temperatures.

[Brief explanation of the drawing]

1 and 2 are schematic vertical cross-sectional views of a battery according to an embodiment of the present invention, FIG. 3 is a diagram showing current-voltage characteristics, and FIG. 4 and FIG. 5 are schematic vertical cross-sectional views of a conventional battery. 1... Positive electrode active material, 3... Negative electrode. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] 1. It is characterized by consisting of a negative electrode using lithium as an active material, a positive electrode using an iodine-added charge transfer complex having a quaternary ammonium group as an active material, and a solid electrolyte produced by a reaction between lithium and the complex. battery.