JPS63187571A - Positive plate for battery and its manufacture - Google Patents

Abstract

PURPOSE:To stabilize open circuit voltage for a long time, to enable the residual capacity to be estimated from the change of open circuit voltage, and to obtain a battery having good high rate discharge performance by adding a specified ratio of phosphoric acid to active material mainly comprising hydroxides in which the content ratio of cobalt to nickel and cobalt is specified. CONSTITUTION:1-70 wt% [{P/(Ni+Co)}X100] phosphoric acid is added to active material mainly comprising hydroxides in which the content ratio of cobalt to nickel and cobalt is 15-90 wt%. By using hydroxides in which the content ratio of cobalt is 30-75 wt%, the potential stability of a positive electrode which is allowed to stand in alkaline aqueous solution and during charge- discharge cycle is increased and high rate discharge performance is improved. Furthermore, by adding phosphoric acid, even it the content ratio of expensive cobalt is decreased to 15 wt% or increased to 90 wt%, the performance equivalent to or exceeding that of a conventional positive plate can be obtained.

Description

[Detailed description of the invention]

Industrial applications Wood 5 light, curved lead, cadmium or iron f'! This article is about a battery positive electrode plate used as an electrode plate and a manufacturing method thereof. The positive electrode plate is characterized by an active material mainly composed of hydroxide with a cobalt content of 15 to 90 wt% relative to nickel and balt, and a phosphoric acid content of 1 to 70 wt% [{P/
(Ni + Co ) ) X 1001 is included. By using this positive electrode plate, compared to a battery using a conventional positive electrode plate, it is possible to stably determine the remaining capacity of the circuit current (changes in current or current), and the capacity is high. rate 1
A battery with good 1i battery performance can be obtained. . Conventional technology Currently used primary battery positive electrode active materials include manganese dioxide and silver oxide, and secondary battery positive electrode active materials include carbon dioxide.
) and Ninonol hydroxide. These active materials are selected depending on the purpose. In recent years, as devices have become smaller and more compact, new, higher-performance primary and secondary batteries are expected to be used.1.Recently, positive electrode active materials! 1, the cobalt content chamber for nickel and cobal I ~ is 30
A positive electrode plate using an active material mainly consisting of 1171 hydroxide of wt% or more, and an f2 made of cadmium, zinc or iron.
The noflukaline battery constructed with the h plate has a △h efficiency of approximately 100% compared to the conventional battery using nila hydroxide.
It was found that the battery capacity≠ can be easily determined by the rjtl I voltage, which is extremely high as %, and has the characteristic that the open circuit 1u voltage changes appreciably with charging and discharging. 60-163382). Further improvements in the performance of batteries with such new functions are expected. Problem L [The Δh efficiency of the positive electrode plate using a suspended active material is 1~
It was found that the change in the interstitial position with charging and discharging is large. Do, もd欣“, U
When you repeat this, the potential gradually fluctuates in a circular direction, and the conventional leek 9le song! f) '=fx Pond or Nickel Cadmilla l
Eh Sora H11,! It has become clear that the nickel hydroxide positive electrode plate has a flaw that the fi characteristic is almost the same as that of the nickel hydroxide positive electrode plate used in the industry. In addition, since cobalt is more expensive than nickel, it inherently has the disadvantage that (2) 1- becomes 8. Phosphoric acid was added in an amount of 1 to 70 wt% C(r),'(N
By including 10Co)) x 1001, the conventional cobalt content can be reduced from 30 to 75W
The problem when using 9G hydroxide is alkaline aqueous solution. , which has improved the rate discharge performance. Furthermore, by adding phosphoric acid, the content of 81% of baltic acid is increased by +5
Even if the content is reduced to wj%, the content will be reduced to 90wt%.
Even if it is increased to , the conventional positive j4 + provisional and lil etc.
11 Noh of 1! ? It was designed so that it could be done easily. Implementation 1t11 The main light gate under varnish will be explained using an example. . First, the positive electrode active material used in the present invention is manufactured by the following method. Na J no, Kobal 1- meeting)+

[
A chamber containing metal cobalt is used for 18 times the amount of metal nickel and metal cobalt in the active material. IIJt5, cobalt fi content = <co/(N
i + CO)) x 10100 (%). (a) A mixed solution with a cobalt content t'i of 15 to 90 wt%, such as a mixed solution of BN M nickel and cobalt nitrate, a mixed solution of nickel chloride and cobalt chloride, a mixed solution of nickel sulfate and cobalt sulfate, or; Well these P,
After adding phosphate ions or phosphoric acid to the combined solution,
Water gate (hysodium, potassium hydroxide, water gate libram, etc. glue 7 lucarin volume, block with in 1'f!, then wash with water and dry.
t' (mixed solution of (U, e.g., mixed solution of nickel nitrate and cobalt sulfate, nila chloride), mixed solution of Δth hikobal 1-, mixed solution of nickel sulfate and cobal sulfate E~ : Or in a mixed solution of these, water-resistant chlorium, potassium hydroxide, sluice containing phosphorus ion, etc.
Rum, etc.)' After adding the lucali solution, wash with water and dry through a sieve 1
゜(C) = Balt content of 15 to 90wt5'5 nickel nitrate and 1Ir1 cobalt [-'61% or more] A solution containing phosphoric acid or a phosphate salt is added to the solution. ((,+nt heat treatment at 110-350℃, the (
Soak in an alkaline solution of hydroxide, potassium hydroxide, lithium hydroxide, etc., then rinse with water and dry. (d) Cobalt content is 15-90W (% bl'l
ll! A mixture of I niggle and nitric acid 1 pal 1 or (
The J, An solution was heat-treated at 110 to 350°C ((, helium hydroxide containing phosphate ions,
Alkaline solutions such as potassium hydroxide and lidium hydroxide:
t.: Immerse in oil, then wash with water and dry a. Basically, the positive electrode active material used in the present invention can be produced as described above, but specific examples and effects thereof will be described in detail below. Example 1 A mixed aqueous solution of cobal nitrate l~ and nickel nitrate such that the n content of cobal 1- was 40 wt% [PI+=1, ratio +1'21. Go (20”C) ], Phosphorus W (
113P 04 ) was added thereto, and then an aqueous solution of hydroxide No. 1 Heliu-11 having a specific gravity of 1.20 (<20° C.) was added. The resulting sink! After washing 2 items with hot water, 130℃
After drying it for 201 minutes, I made it into a VR machine using a ball mill.
An active material powder used in the present invention having a mesh size of 0.00 mesh or less was obtained. Example 2 l1rI with a Kobal-1 content of 40 wt%
Kitago aqueous solution of cobalt moromi and nickel nitrate [PH=
1, specific gravity 1.60 (20°C)] was added an aqueous solution of tuttrium hydroxide containing 0.2M NaH2PO2 with a specific gravity of 1.20 (20°C). The resulting precipitate was washed with hot water, dried at 130°C for 2 hours, and then ground in a ball mill (f5) to obtain active material powder used in the present invention having a mesh size of 100 mesh or less. ? Ta. Example 3 ■] Ll' such that Baltic's 3 right' is 40wt%
l M mll silt llr! After adding 36i/λ of phosphorus Fa (1'3 POs >) to a mixed aqueous solution with acid nickel [PI+-・1, specific gravity 1.60 (20°C)], it was heat-treated at 250°C for 1 hour. 1 in a sodium hydroxide aqueous solution with a specific gravity of 1.20 (20°C).
After 1,1 min. i6 treatment, it was dried at 120°C for 1 hour. After that, it was washed with hot water, dried at 100℃ for 1 hour, and crushed with a ball mill to make 100 mesh: L.
Example 4 A mixed aqueous solution of cobalt nitrate and nickel nitrate such that the cobal content was <i>40 wt% [PH=1,
specific gravity 1.60 (20°C)] was heat-treated at 250°C for 1 hour. This product was mixed with 0.2 M sodium phosphate (Na 1+2 PO2) at a ratio jfi 1.2
0 (20°C) for 1 hour, and then further soaked at 100°C for 111. 'Dry for 1 minute,
Thereafter, it was ground in a ball mill to obtain 1:7 of the live material T1 powder used in the present invention having a size of 100 mesh or less. Next, a mixed powder of 100 parts of the active material powder obtained in Examples 1 to 4 of L and 10 parts of carbonyl nickel powder as a conductive material was dewired with 40 parts of an aqueous solution of 1Wt96 carbo-1-dimethyl cellulose and then paste. It was made into a shape. Next, this paste was filled into a foamed Niracle body (manufactured by Sumitomo Electric Industries, Ltd., trade name Selumetsu l-) with a thickness of 1 mm.
After drying for C1 hour, the size according to the present invention is 30ffiI1
The positive root of 1×40111In is 11. In addition, Example 1
So 1! Positive (ν treatment is Δ, same〈
The one in Example 2 is written as B, the one in Example 3 is written as C, and the one in Example 4 is written as [). In addition, in the above example, the active substance τ1 powder was filled into the foamed Niracle body, but nickel cadmium 1
tJ can also be produced using a sintered Niracle substrate, which is an active material holder for -8 ponds. Example 5 A sintered nickel substrate with a porosity of about 80% was coated with 3627'
1. Contains phosphorus M (H2PO4) and has a Kobal i content of 401%. I'l M Mixed aqueous solution of cobalt and nickel nitrate 1 [PH=2, specific gravity 1. GO (20℃)
] after being impregnated under reduced pressure, immersed in a futrium hydroxide aqueous solution with a specific gravity of 1.20 (20°C) for 1 hour, and then
It was dried at 120°C for 1 hour. Thereafter, it was washed with hot water and further dried at 100°C for 1 hour to obtain the 1T electrode according to the present invention. Example 6 Sintered Nicklure 7% li with a porosity of about 80%, 3
61772 phosphoric acid (H3POa) and a cobalt content of 40 wt% lIr1M cobalt and lI
Mixed aqueous solution with l'l M nickel [P l-1= 2
, specific gravity 1.60 (20°C)] was impregnated under reduced pressure,
Heat treatment was performed at 250°C for one cycle. After that, specific gravity 1
．． 20 (20°C) hydroxide] 1 in a helium aqueous solution
After soaking for an hour, washing with water and drying at 100°C for 1 hour, the water was dried.
It's 7. The content of phosphoric acid contained in the iE polar roots Δ, C, E, and F according to the present invention is:]wt%, positive (transfer number 13,
The content of D was 2.711°C%. In addition, real IA
! 'A heat treatment for 3, 4 and 6 Jll! W degree is 1
If the temperature is less than 10°C, no hydroxide is produced by thermal decomposition. Furthermore, if the heat treatment temperature exceeds 350° C., oxides of nickel and cobalt will be produced, and the activity as an active material will decrease, which is not preferable. Using one of these positive electrode plates Δ~F and two sintered cadmium negative electrode plates as counter electrodes, the ratio ffl was 1.2 as a 1M solution.
A fland-type battery with a nominal capacity of 100IIIAh was fabricated using a potassium hydroxide aqueous solution at 50°C (20°C), charged at 0.5Cr for 2.2 hours, and discharged at 0.5Cr for 2.2 hours.
Charging and discharging up to OV (vs, tl(] / H(10)) at 5C was performed for 120 nicles at 50°C. Charging and discharging cycle of the potential of the positive electrode plate 30 minutes after the start of charging 1 and 2 after the start of discharging. The changes in Y are shown in Figure 1 for the charge potential and Figure 2 for the discharge potential.For comparison, a mixed aqueous solution of 1 balt and 6n nickel without phosphoric acid was used for comparison. Example 6 except that
Conventional in 1.4+ 1J made in the same way as
The change in orientation of 'tG is also shown. Figures 1 and 2
From the figure, it can be seen that the potential during the charging and discharging process of the present invention's positive (~temporary charging/discharging overculm JiJ) hardly changes as the 1-h charging/discharging cycle progresses, whereas the conventional positive 4! As the number of charging and discharging cycles increases, the voltage gradually reaches C1, and becomes almost constant when the charging/discharging cycle reaches about 100 + 2 cycles. The potential of a nickel hydroxide positive electrode plate with a cobalt content of 4j''?/ of 2.~10 wt% (J was the same as that of the nickel hydroxide positive electrode plate). As mentioned above, if the cobalt content is 1
Similar experiments were conducted in the range of 5 to ioowt% in 5w% increments to examine the stability of the charge/discharge potential, but the positive electrode plate that did not contain phosphoric acid did not have potential stability11, especially at i'SF1 degree. However, at high temperatures of 40° C. or higher, the potential change was significantly large. This means that the cobal l- content is 30
The Δh effect, which is a characteristic of alkaline batteries that contain more than wt% of nickel hydroxide or cobalt hydroxide in the L form, is high, and the remaining capacity of the battery can be detected by changes in the open circuit pressure. The 11 points of being able to do so mean that they are gradually lost during charge/discharge cycles, and this tendency was particularly noticeable at high temperatures. Therefore, it can be said that the potential stability of the positive electrode plate according to the present invention is extremely good. This electricity (1'
It is clear that the stability of l is obtained by the addition of phosphate ions. II-The number of poles is made, and the pair (~
A roll type 7344 made of a 60% wood-bamboo dispersion solution containing polytetrafluoroethylene powder is wrapped in a polyamide non-woven fabric and a polyethylene microporous separator, and then the electrolyte solution is Using a potassium hydroxide aqueous solution with a specific gravity of 1,300 (20℃) saturated with curved lead oxide, a flanded type battery with a °C1 nominal capacity ω of 100m△h was fabricated, and the charge was 1C and the terminal voltage was 1. Charging and discharging was repeated at 35°C until .85'J with a voltage of 1C and a terminal voltage of 1.0. Charging/discharging leakage is 150 nicles [1 after charging is completed]
FIG. 3 shows the relationship between the open circuit potential of the positive electrode plate at 5 minutes, the open circuit potential of the positive electrode plate at 30 minutes after the end of discharge, and the cobal l- content of the active positive electrode 150. In Figure 3, 11 is the positive electrode plate of the present invention to which phosphoric acid has been added, I is the conventional positive electrode plate 1'I bamboo to which phosphoric acid is not added. In other words, there is almost no difference in the open-circuit potential at the start of the discharge (1-1) between the positive electrode plate 1-1 according to the present invention and the conventional IT pole, but the open-circuit potential at the end of the discharge is The difference in potential becomes clear when the cobalt content increases to 15 wt% or more.The difference in potential becomes clear when the cobalt content increases to 15 wt% or more.The difference in potential becomes clear when the cobalt content increases by 1. I
There is a positive direction, but the conventional positive;
The cobalt content is 15W

[The fact that it doesn't become mean even if it exceeds % and remains almost constant is interesting. This shows that when the cobalt content is 15W% or more, the effect of adding phosphoric acid is clearly visible, and the difference between the open circuit potential before the start of discharge and after the end of discharge is almost the same as +II+ at the beginning of the charge/discharge cycle. In addition, when the cobalt content of a conventional positive electrode plate reaches 15W1% or more, the potential after the completion of the 1/1 charge will fluctuate in a negative direction as the charge/discharge cycle progresses. .However, the cobalt theory 4'i 4; is !10 W t % <-', J
! J Ero and 1% phosphorus added to the engineering school temporary discharge key 3 (
Since there is almost no difference between Rinoden 1+"114 and the case without additives, the effect of phosphoric acid is that the content chamber in Kobal 1 is 90W.
If it exceeds t%, it can be said that it decreases. Therefore, the cobalt content is 15 to 90 Wt'? 6 is preferred. Furthermore, the discharge potential characteristics, for example, the discharge midpoint potential (potential at half the discharge duration), in the case of a conventional tTKi plate, if the cobalt content chamber is 15 to 90 wt% or more, the cycle progresses. However, in the case of the positive electrode plate of the present invention, the change in the electric potential of 1 < l was almost stable (,1. In order to investigate whether it is also stable with Ikuru's Junction 11, the active material J according to the present invention, prepared without adding phosphoric acid in Example 3, was also tested. positive electrode active material r
The X-ray diffraction pattern of jK is shown in FIG. From the figure, the positive electrode active material according to the present invention! 1. Although there are no diffraction peaks in J, the conventional positive electrode active material τ'jK[ is Ni (Co) dissolved in nickel and cobal.
(A peak of 01-1>2 is clearly recognized. From this, the active material J of the present invention is clearly in an amorphous state compared to the conventional positive (low activity)1"1. It was determined that the surface condition was 11 [11].Furthermore, chemical analysis revealed that Ni (Co) in the active material
When we conducted a quantitative analysis of the higher oxidation power of ``+ (n>2>), it was found that the conventional cathode active material tIK contained 6.3 wt% of cobalt with a valence of more than GJ2. λ[
The positive electrode active material J according to the present invention contained only 1.5 wt%. The effect of this can be summarized as follows: (1) When the cobalt content is 15 wt% or more by using phosphate ions or phosphates as in the present invention, the effect can be summarized as follows: When a hydroxide of - and nickel is made, a hydroxide with a lower degree of heat (b) and a larger surface area than the case without additives is produced. Moreover, it is thought that the condition is such that it is difficult to oxidize due to the presence of ?8q in the alkaline aqueous solution. , In the fruitful annual G, positive electrode plates with various phosphoric acid levels were manufactured, and sintered cadmium f was used as the counter electrode.
M! The ratio of plate 2 (father) to electrolyte is Φ L250 (2
A furan 1-tube battery with a nominal capacity of 100 mΔ[) was made using a potassium hydroxide 1 aqueous solution at 0°C), and after being charged at 0.1C for 16 hours, it was charged at 5C at 0V (vs,
lI[) ”11g0) Use when paralyzing discharge!K] (Nickel and cobalt in the active material are Ni<Co) (0
11) z, and the light (assuming that the l'i electric reaction follows a one-shot reaction) is shown in Table 1. From Table 1, when the phosphoric acid content [{P/(Ni → C.))X100] is 1 wt% or more -E, the utilization rate is good (1.1), indicating that the effect of phosphoric acid is increasing. I understand. Further, when the content of phosphoric acid exceeds 70wj%, a slight decrease in the utilization rate is observed, and as the content of phosphoric acid increases, the energy density per volume decreases accordingly, so the practical efficiency decreases. Therefore, from a practical point of view, the phosphoric acid content T I' must be 701% or less. According to the present invention, i′
[This is thought to be because the mythical substance is in an amorphous state, so the surface area is small, but the uniformity of t1 reduces the overvoltage during energization. . (13,6ζfζIn addition to the actual example, the water valve Ill mentioned above
A variety of positive electrode plates were manufactured using the positive electrode active materials manufactured by the methods (a) to (d) for use in the manufacturing methods (a) to (d) of the positive electrode active materials used in the above methods, and were subjected to tests. Similar to the example (1 effect was to change the Song Dynasty to 1!) As mentioned above, the present invention has been applied to the present invention. Since there is little variation in potential due to discharge cycles, the residual capacity M can be stably known over a long period of time based on changes in the open circuit potential.Moreover, the active material according to the present invention is amorphous 71 compared to conventional active materials. Since there is only one state, the charge/discharge reaction is highly active. Therefore, according to the present invention, it is possible to manufacture a secondary type 11j5 and a primary battery that have features not found in the prior art.

[Brief explanation of the drawing]

Fig. 1 is a comparison diagram of the change in charging potential of the positive electrode plate according to the present invention and the conventional positive electrode plate as the charge/discharge cycle progresses, and Fig. 2 shows the discharge of the positive electrode plate according to the present invention and the conventional positive electrode plate as the charge/discharge cycle progresses. Comparison diagram of potential changes, Figure 3 shows the relationship between the open circuit potential and cobalt content after the completion of charging J'3 and the completion of discharging of the positive electrode plate according to the present invention and the conventional positive electrode plate. ,
FIG. 4 is a comparison diagram of the X-ray diffraction patterns of the positive electrode active material according to the present invention and the conventional positive electrode active material. A piece of t'y cycle drinking bald erection 1 [? Iul loser 3rd

Claims (3)

[Claims] (1) An active material mainly composed of hydroxide with a cobalt content of 15 to 90 wt% relative to nickel and cobalt,
Phosphoric acid is 1 to 70 wt% [{P/(Ni+Co)}×1
00] A battery positive electrode plate characterized by comprising: (2) A mixed solution of nickel nitrate and cobalt nitrate containing nickel and cobalt with a cobalt content of 1
A step of treating a mixed solution of 5 to 90 wt% with an alkaline solution such as sodium hydroxide, potassium hydroxide, lithium hydroxide, etc., and containing phosphate ions or phosphates in the mixed solution or alkaline solution. A method for manufacturing a positive electrode plate for a battery, characterized by: (3) After heating a mixture of nickel nitrate and cobalt nitrate or a mixed solution thereof at 110 to 350°C with a cobalt content of 15 to 90 wt% relative to nickel and cobalt, sodium hydroxide, potassium hydroxide, hydroxide 1. A method for manufacturing a positive electrode plate for a battery, comprising a step of treating with an alkaline solution of lithium or the like, and containing phosphate ions or phosphates in the mixture, mixed solution, or alkaline solution.