JPS59134562A - Lithium secondary cell - Google Patents

Abstract

PURPOSE:To obtain a small-size, high energy-density lithium cell whose charge- and-discharge capacity is large and from which a large current can be drawn out, by using electrically well conductive (Cu1-xMx)2V2O7 as positive active material. CONSTITUTION:Positive active material used for a lithium cell in the present invention has the general formula (Cu1-xMx)2V2O7 (where, M represents either one or two or more kinds of rare earth elements such as Sc, Y, La, Dy, Sm, Gd, or the like and tribalent elements such as Cr, Bi, Sb, Fe, Mn or the like, x is also a real number less than 1 and its value is preferably to be 0.25 or less.) And the mixture of said positive active material and a binding agent power such as polytetrafluoroethylene is pressure-molded in a film-form onto a support of nickel, stainless steel or the like in order to obtain positive depolarizing mix 6. Lithium acting as negative active material is processed to a sheet metal just like that of a general lithium cell, and said sheet metal is pressure-molded on an electrically-conductive net made of nickel, stainless steel or the like. The energy density of the thus produced cell in high not only when its discharging current is small (1mA) but also when said current is large, thus showing an excellent characteristic of a cell.

Description

[Detailed Description of the Invention] This article relates to a rechargeable pond that is small in size, has 114 leaves, has a large amount of light, and uses lithium in bamboo and lithium. It is something.

There have been many inquiries regarding high energy density batteries that use lithium as a negative active material from Juto, for example, intercalation compounds of graphite and fluorine as ilE active materials, negative active materials, etc. 'tt ('171b, which uses lithium gold oysters, is known.

(See U.S. Pat. No. 3,514,337 Akira Saimei).

In addition, lithium batteries (
Matsushita-beki@) and lithium-ion batteries (manufactured by Sande-yang-kei (1)) that use manganese dioxide as primary, active, proboscis, and nostrils have already been sold.However, these batteries are It was a city pond, and it had the disadvantage of not being able to fulfill its needs.

Regarding secondary batteries that use lithium as the negative electrode active material, batteries using sulfides of titanium, zirconium, hafnium, niobium, tantalum, and vanadium, as well as selenide and telluride ( US Patent No. 4
．． 009.052 Akira Saimei) and batteries using chromium oxide, niobium selenide, etc. (J, Electroc
hem, Soc, 124 + A 7. (197
7) 968, J, electrochem, S
oc, 124, All 7° (1977),
325) and the like have been proposed, but these batteries cannot necessarily be said to be sufficient due to the customization and economic efficiency of the batteries.

A lithium battery using gold vanadate as the positive electrode active material is shown in U.S. Patent No. 3.681.143, but in this patent, C
Only those having the structure us (vo, )z are shown as examples, and there is no description of the characteristics of Mitsutoshi Samurai. Cu2 v, O? as positive electrode active material? We are developing a rechargeable lithium battery using a rechargeable lithium battery.

Cu2V20. It is safe to mix acetylene black, graphite, etc., with the active material used as the active material for the positive electrode, to improve the electron conductivity of the positive electrode mixture.

However, adding a conductive agent that does not act as an active material reduces the amount of energy charged per potential volume of the positive electrode (this is contrary to the high energy density of the positive electrode). In order to increase the charging capacity, it is necessary to lower the mixing ratio of the sleep-inducing agent within a range that maintains the required sleep performance. The important point is to make people feel positive.

The present invention was developed in consideration of the current situation, and an object thereof is to provide a lithium battery that is compact and has excellent characteristics.

Taking a rough look at the lithium battery proposed by Kaburaaki Moto, the positive electrode active material has a high concentration of J/J particles (Cut -Z).
M).

Vz O? (M: Sc, Y, La, Dy,
Ichido stubborn elements such as Sm and Cr + B i + S b
+ Fe + Mn43: -[1 of +Itl element
The negative electrode active material is lithium, and the hemolyte is chemically stable to 1Effi active material and lithium, and the lithium ion is the positive electrode active material. + for reaction: 6. The special feature is that it is a substance that helps.

According to the lithium battery according to the present invention, 2! l), good spiral (Cut, -, M,)2 vt O? positive 1
Since it is used as a desk top 4, it has a large charge/discharge capacity, and has a large discharge current compared to conventional lithium batteries.
It has the advantage of being able to produce - The present invention will be explained in detail below.

The letterpress and material used in the lithium press according to the present invention are of the one-throw type (Cu1-χMχ) and o7, as described above. In the formula, M is S e HY* L
a Rare elements such as sDy, Sm, and Gd, and Cr+ B
It represents one or more trivalent elements such as Sb+Fe and Mn. Further, χ represents a real number less than 1, and the lithium battery according to the present invention preferably has a value of 1 of χ.
It is preferable that 1 auto° is 0.25 or less. χ is 0.2
If it exceeds 5, the solid +17 limit will be exceeded, resulting in a mixed liquid state with MVO4, which may lead to a decrease in the RI/l12:temperature pressure and a decrease in cycle life.

The production of the double chain in the present invention is as follows (Cu
1−χMχ)t V20? powder or a binder powder such as polytetrafluoroethylene on a support such as stainless steel or the like. Form into a king shape. Or (Cu, -χMχ)z V20? In order to give the powder a certain degree of oxidation, a conductor powder such as acetylene black is mixed, and a binder powder such as polytetrafluoroethylene is added in some cases. The HetH compound can be formed by pressure molding on a support made of nickel or stainless steel.

Lithium, which is negative 1 and active 1, is formed into a sheet like that of a general lithium battery, or by pressing a sheet of lithium onto a conductor network such as nickel or stainless steel.

As the electrolyte, propylene carbonate, 2-methyltetrahydrofuran, dioxolene, tetrahydrofuran, 1,2-dimethoxyethane.

Aprotic organic solvents such as ethylene carbonate, γ-butyrolactone, dimethyl sulfoxide, acetonitrile, formamide, dimethylformamide, nitromethane, and LiClO4, LfAICl.

Li BF'4 + LiC1, LiPF6, Li
Combinations with lithium salts such as AsF6, solid electrolytes using Lt+ as conductors, molten salts, and other known electrolytes that are generally used in batteries that use lithium as a negative electrode active material can be used. .

Further, if necessary, a thin film made of porous polypropylene or the like may be used in the battery configuration E1.

(Cul -1Mz)2 Vt 07 is the original voice of the original V20a, Cll0. M2O3 (e.g. S
C203+ Y203 w LaOs + Dy203
+Gr2 oB t Bit Os + Fez 0
3 4 (D Molar ratio of one to two is 1:2 (1-χ) =
It can be synthesized by mixing in a ratio of χ and baking in air at a temperature of 620 to 650'C for 24 hours + 111 hours.

Next, the present invention will be explained with reference to an actual example, but the present invention is not defined in any way by this.

Note that the production and measurements of batteries described in Examples were performed under an argon atmosphere.

Embodiment 1 FIG. 1 is a schematic diagram of a coin-type battery which is a specific example of the Nyorubeike of the present invention. 11d1 is a stainless steel sealing plate, 2 is a polypropylene gasket, 3 is a stainless steel real case, 4 is a lithium failure, 5 is a polypropylene ring separator, and 6 is a positive electrode mixture.

Place lithium 4 at a pressure of J70 in the sealing hole 4 Ji 1, apply it to the concave 9 part of the gasket 2, and press the opening of the Xikou ridge 1 (the separator 5 and the positive electrode mixture 6 in this order). The 1'F sieve was impregnated with IM-LiC104/PC+DME (1:1 ratio) (equal volume mixed volume of propylene carbonate and 1-2 dimethoxyethane) as a direct solution. Cover and tighten the positive electrode case 3 to a diameter of 23 mm.
A coin-shaped battery with a thickness of 2 mm was manufactured.

The positive electrode mixture 6 has (Cu0.9S) as a positive active image quality.
cO,1)2 Vt 07 and Ketjenblack E
rτ6 polytetrafluoroethylene with a ridge ratio of 70:
The mixture was mixed in a ratio of 27:3 using a shakumasu-iso, roll-formed, and punched out with a 0.6 mm thick soba punch to form a disk-shaped old electrode with a diameter of 16 mm and a weight of 0.129 g. Positive electrode active image quality (Cub, 9 Sc O, 1) 2
Vt 07 is Cub, S ct Os , Vt 0 *
were mixed in a molar ratio of 1.8:0.1:1 and fired in air at 630°C for 24 hours + dl. ,-.

In this way, we investigated the susceptibility of the left-handed curve to the open-air tonne flow during the cultivation and downhill tun gamma. Figure 2 is a diagram showing the results of the sailing test and saving. At 1mA, the discharge of 9 hours of acid secretion until the end beam, critical pressure drops to IV is 520 Ah/kg, and the energy density IW is 1150 wh/kK. Met. Also, the difference in the discharge curve depending on the size of the parish jet is small.

For comparison, Cu2Vt 07 without any addition of Sc was used as a conventional tIL cell for positive electrode activity and image quality, and a critical condition prepared in the same manner as above was tested for recovery under the same conditions. Figure 43 shows the weight curve of this battery.

Old electrode activity until battery pressure drops to 1V, 4//lJ
The quality was 473 Ah/kg, and the energy was 1005 wh/kg. There is a big difference in the leaving curve depending on the size of the discharge current, especially at 10 mA,
The feeding density of the three stations of 20mA discharge is small.

On the other hand, (Cub, 9 SC0,1)2 Vt
O? Critical condition (
・Jj; 21.71) not only has a high energy density in a low current (1 mA) discharge, but also has a high energy sliding degree even when the Hoichicho flow is large, indicating a collapsed time.

In addition, the combination of 1 mA constant five-current discharge, the id1 central sum χ of Sc and the four sales lma of the IV final market release market 1 stop, (C
u, −χScχ)t Vt 0? Corresponding to the conductivity of χ
It is maximum at -0,1, but O,OS<knee χ<0.15
There is no big difference in id in the range of , and both are larger than when χ = 0.

Example 2 Produced in the same manner as Example 1 (CuO, 8ScO-2
) 2 Vt 07 was used as the positive electrode active image quality, and constant current charging and discharging at 1 mA was performed. In the charging/discharging cycle, when the pressure drops to 1V when left unused, the cycle is completely repeated: after waiting for a rest period, the battery is charged for the same amount of time.

FIG. 4 is a diagram showing the results of the charging and discharging test. The figure shows 1
The 1st, 2nd, and 13th editions are shown, but there are almost no changes to the original songs. 100 like this
% deep charging and discharging showed good charging and discharging characteristics.

Example 13 iE+4 active matrices (Cub, 9 Yo, 1)z
Cub V2Or.

YtOs, V2O5 molar ratio 1.8:0.1:1
Mix at 630℃ in air for 24 hours 1;
1chi ljV and sum hXL&. ko (D (Cub, 9
Yo, 1) 2 Vt 07 i'E1 umbrella f1<-)
A 1L pond was prepared in the same manner as in Example 1 except that it was homogeneous. When I streamed a piece of music to the C I had made using Frozen 1 at a constant current of 1mA, the result was a piece of Nonoebi music as shown in Figure 45. ■The discharge capacity until the voltage drops to 1V is 50 Q Ah/kg, and the energy density is 1
It was 1110 wh/kg. Furthermore, the influence of the discharge curve due to the difference in the magnitude of the discharge direct current was the same as in the case of Example 1, and exhibited characteristics that were superior to the conventional battery.

Also, the relationship between the total 1f and the discharge capacity density 1w is Sc i
It was similar to the conversation at the rental office.

Example upper plate g+# Quality L Te C) (Co O, 95Dy0
．． 05) 2 V207 to CuODy20s + V20
5 in a molar ratio of 1.9:0.05:1 to 7-, in air at a range of 620°C to 630°C for 24 hours + i1
．． ' + It was removed by firing.

Kono (C+i0.95 Dye, '05) 2 V20
7 K positive pupil active proboscis (V1 except for use as q)
A battery was fabricated with a size of 1 inch. Using the city C view prepared in this way, r-p 4 rJiT and I attack' city of 1 m8 were attached. - When the voltage of the battery decreases to 1V, it is 480.
Ah/kg, 1 energy is 10 fi Owh/k
G There was. ′! The effect of the size of the current and the normality is actually that it shows a good characteristic even if it is a troublesome 1 and the same port is used in direct current.

Example positive image active material (Cub, 95 SmO, 05) 2
V207 was mixed with C+i0+ 5rn203+ V205 at a molar ratio of 1.9:0.05:1 and cured in air at a temperature of 620 to 630°C for 24 hours.
This (CuO,955m0.05)2 V207 is i''
1" to be used as an active material '6: J, and the outside was made in the same manner as in Example 1 of the actual sieve. This battery was used as an example 1.
~ Comparing with Example 4, we investigated the influence of the size of 1 mA constant flow market and discharge current. Rice milling, real sister 1 * 114 Dy+#
It showed almost the same temporality as the sound.

Real sister 1 row 6 positive, l1lj f&I 6 (Cu11.9 C
ry, 1) Cube 2 V2O, Crto3 +
It was prepared by mixing V2O5 at a molar ratio of 1.8:0.1:1 and forming it at 620° C. for 24 hours in air.

A battery was produced in the same manner as in Example 1 except that this (Cub, 9 Cry, 1)2V207 was used as the positive electrode active material. The battery thus prepared was subjected to constant current discharge at 1 mA. The discharge capacity density until the battery voltage drops to IV is 50 Q Ah/kg.

The energy density was 110 wh/kg. Furthermore, even in the case of a large discharge current, similar to Example 1, the battery exhibited superior characteristics compared to conventional batteries. In addition, the relationship between Cr's okishiki and discharge capacitance increases dramatically with the addition of Cr's okishunshun. In addition, the charging characteristics also showed better characteristics than the Tosong battery as in Example 2.

The characteristics of typical batteries obtained according to the present invention are all shown in Table 1.

For comparison, conventional Cu2V2O is used for fi9.

The characteristics of the pond using as a homogeneous cathode active are shown.

(Left below) Table 1 Characteristics of typical batteries according to the present invention 1)
1mA constant (r normal change pigeon (death Hate' auxiliary voltage drops to 1-V at various places 2) 1mA, charging capacity of 100 inches deep, mortality rate is 80 degrees 3) To curve Cu without gold 1, V2
07As explained above, it has good conductivity (Cul-χ
The lithium secondary battery according to the present invention using Mχ)zVtO□ as the positive @ active "rostol/d" has a large charge/discharge capacity and has the characteristic of being able to outperform conventional batteries with a large discharge current. It has the advantage that it can be used in various fields as a high energy density reservoir.

[Brief explanation of the drawing]

Figure 1 shows one of the coin-shaped 'serious conditions' in an embodiment of the present invention.
Figure 2 shows the relationship between the magnitude of the current and the discharge curve in the present invention. -g
Figure 3 shows the relationship between the magnitude of the battery current and the discharge curve in the critical state of reverse charging, and Figure 41 shows the relationship between the battery charge and discharge cycle and the discharge time in the central example of the present invention. FIG. 3 is a diagram showing the relationship between direct pressure changes. 1... Stainless steel Murakuchi plate, 2... Polypropylene gasket, 3... Stainless steel correction pupil case, 4...
... Lithium @ Ususa, 5... Polypropylene separator, 6... Positive electrode mixture.

Claims (1)

[Claims] Regular active material, (Cu, -, M, )2 V2 o7
+, fx le composition (M is Sc+ yl L
a, rare earth elements such as Dy+ Sm+ Gd and Cr;
The former 1sblFe, represents one or more selected from the trivalent elements of Mnl, and χ represents a real number less than 1),
@The extremely active material is lithium, and 'Sazaki's 6-point positive soul life'
Of course, it is chemically excretory to acids and lithium, and is the only substance capable of carrying out many electrochemical reactions with lithium ions. It is also possible to emit light using a lithium secondary battery.