CN1521878A

CN1521878A - Preparation method of cylindrical press ring type primary or secondary Zn-Ni battery

Info

Publication number: CN1521878A
Application number: CNA031029000A
Authority: CN
Inventors: 高效岳; 沙永香; 蒋正治; 邱德瑜; 唐琛明; 沈涛
Original assignee: Jiangsu Haisida Group Co ltd
Current assignee: Jiangsu Haisida Group Co ltd
Priority date: 2003-01-30
Filing date: 2003-01-30
Publication date: 2004-08-18

Abstract

The invention discloses a preparation method of a cylindrical press ring type primary and secondary Zn-Ni battery. The positive electrode is NiOOH or Ni (OH) ₂ The graphite, the additive and the KOH electrolyte are taken as raw materials, and are subjected to the working procedures of dry mixing, wet mixing, tabletting, crushing, screening and the like (generally called granulation process) to prepare anode powder, and the anode powder is pressed into a ring shape and is filled into an anode current collector steel cylinder. The negative electrode is made into paste by Zn, znO, additive, binder and KOH electrolyte and called negative paste. The diaphragm is rolled into a circular tube shape, the back cover is inserted into the middle hole of the anode ring. Injecting negative paste into the diaphragm tube, inserting negative current collector, and sealing to obtain the final product.

Description

Preparation method of cylindrical press ring type primary or secondary Zn-Ni battery

Technical Field

The invention relates to two new energy sources.

Background

The primary alkaline zinc-manganese battery which is popular in the market has the open-circuit voltage of 1.5-1.65V, the working voltage is S-shaped along with the time, no obvious platform exists, and the working time is longer at 1.2-1.0V. When the output current is large, the capacity is reduced. For example, the AA type can discharge about 60 minutes at 1 omega and about 1100mAh, and the 10 omega of the battery with the same size can discharge up to 2300mAh. Alkaline zinc-manganese batteries have poor heavy duty performance, limiting their use in certain applications, such as toy cars, video cameras, digital cameras, mobile communications, laptop computers, and the like.

The cycle life of the secondary alkaline zinc-manganese battery is only dozens of times, the first discharge capacity is much smaller than that of the primary alkaline zinc-manganese battery, and the large-current working performance is poorer.

Cd-Ni batteries are toxic, have a working voltage platform of 1.2V and are limited for civil use.

MH-Ni batteries are quite expensive and have a working voltage plateau of 1.2V.

The Zn-Ni battery has good heavy load performance, high specific energy, abundant storage, no pollution, proper price, 1.73V open-circuit voltage and 1.60V working voltage platform. The Zn-Ni battery is made into a cylindrical press ring type, the working voltage platform is high, and the heavy load performance of the primary battery is better than that of the alkaline manganese battery. The number of times of taking pictures by using one Zn-Ni battery in the digital camera is 4-6 times of that by using an alkaline manganese battery. The secondary Zn-Ni battery has longer cycle life than the secondary alkaline manganese battery, high capacity and good heavy load performance. Although Zn-Ni batteries have more superiority, discharge products Zn (OH) are generated due to instability of Zn in alkaline solution ₄ ^2- Dissolved, zn (OH) when charged ₄ ^2- And Zn is deposited, the charging and discharging times are increased, the electrode is deformed to be thin at the top and thick at the bottom, dendritic crystals are easily generated, the cycle life of the Zn electrode is short, if the zinc electrode contains impurities, oxygen is easily generated, the Zn is self-corroded, the cycle life of a secondary Zn-Ni battery is prolonged, and the large current capacity and the shelf life of a primary Zn-Ni battery are prolonged.

More research workers intensively research square batteries and cylindrical zinc-nickel batteries. There are two types of cylindrical batteries, one is a wound type and the other is an inside-out type. The pressure ring type uses less diaphragms and positive and negative collectors, and electrode active materials can be contained in more parts, so that the price is lower and the capacity is high. The pressure ring type has the advantages that the anode and the cathode are separated, the cathode is arranged inside, the anode is arranged outside, short circuit is not easy, the shelf life is long, the internal resistance is large, oxygen generated by the anode can only be recombined from the battery space to the cathode when the secondary battery is charged, and the space must be reserved in the battery. A primary battery and a secondary battery are manufactured by adopting a press ring type structure.

Secondary cylinder type press ring Zn-Ni battery sanyo electric co, ltdu.s.p6235428 (2001.5.22) reported the use of NiOOH as the positive electrode active material, but not subjected to the granulation process. U.S. P6190801 (2001.2.20) reported the use of Ni (OH) ₂ The positive electrode active material was not subjected to the granulation process.

Ni(OH) ₂ The apparent density (bulk density) is generally 1.6g/cm ³ The apparent density of the oxidized NiOOH is basically the same. The apparent density of the graphite powder is lower, and is generally 0.12-0.25g/cm ³ In between, the expanded graphite and acetylene black apparent densities are lower. Mixing the twoThe ring density is not high when the anode ring is directly pressed, the ring weight is low, and the finished product rate of pressed rings is low. The quantity of active substances loaded in a limited volume is small, and the specific energy is lower.

Disclosure of Invention

The invention aims to improve the manufacturing method of a Zn-Ni primary and secondary cylindrical press ring type battery, increase the material quantity of a positive electrode and a negative electrode, increase the density of a positive electrode ring, and improve the specific energy and heavy load performance of the battery.

The technical scheme of the invention for realizing the above purpose is as follows:

the steps for preparing the primary or secondary Zn-Ni cylindrical press ring type battery are as follows: in the first step, ni (OH) is reacted with alpha-type or beta-type Ni ₂ Or gamma-type NiOOH or beta-type NiOOH as positive electrode active substance, additive, adhesive and graphite, mixing them uniformly, ni (OH) ₂ Or the ratio of the NiOOH anode active substance to the graphite powder in the anode is 8-15: 1; second step, in the above-mentioned mixingAdding 30-40% KOH aqueous solution in a mist form into the uniformly mixed dry powder for wet mixing to obtain wet mixed powder; and thirdly, tabletting, crushing and sieving the wet mixed powder to obtain the anode powder, wherein the tabletting is to press the wet mixed powder for 1-3 times by a roller, the rotating speeds of the two rollers are the same, and the roller can be provided with teeth or not. After pressing once, the flaky material is crushed firstly and then pressed for the second time, the tabletting frequency is determined according to the dryness and wetness of the powder, and the powder is pressed once and dried once. The thickness of the pressed sheet is controlled to be 0.2-2mm. The crushing is to pass the tablets by a wheel with a certain distance, the wheel rotates to crush the tablets or crush the tablets by a swinging type gear, the distance of the wheel is controlled to control the granularity after crushing, the powder with a certain granularity after crushing is sieved by a sieve with 14 to 20 meshes, then sieved by a sieve with 60 to 100 meshes and sieved by a sieve with 14 to 20 meshes, the powder which is not sieved by the sieve with 60 to 100 meshes is anode powder, the moisture, the granularity and the density are analyzed, and the density is controlled to be 1.65 to 1.9g/cm ³ The powder with the granularity of 20-60 meshes accounts for more than 80 percent, the powder with the granularity of less than 100 meshes is called fine powder with the granularity of less than or equal to 15 percent, the water content is 2-5 percent, the powder which does not pass through 14-20 meshes is coarsely mixed with the powder which passes through 60-100 meshes, new wet mixed powder is added, and the third step is repeated after the mixture is uniformly mixed; and fourthly, pressing the qualified anode powder into a ring shape, namely, an anode ring, wherein 3-4 anode rings are arranged in one cylindrical battery, and the ring size is different according to the size of the cylindrical battery. The general ring outer diameter is 0.02-0.1mm smaller than the inner diameter of the steel cylinder, the ring inner diameter determines the distribution of the volumes of the positive electrode and the negative electrode in the battery, the ring inner diameter is enlarged to phi O.15-0.2mm, so that the volume of the negative electrode is enlarged, and the loading capacity is large; fifthly, three or four positive electrode rings are arranged in a nickel-plated steel cylinder together, and the position which is about 2-3mm away from the opening of the steel cylinder is arranged during ring arrangement; and sixthly, re-pressing, namely inserting a rod in the middle of the ring, wherein the rod is 0.01-0.03mm smaller than the inner diameter of the ring, pressing the ring to enable the ring to move downwards to the bottom of the steel cylinder and expand due to deformation, the outer diameter of the ring is tightly contacted with the inner diameter of the steel cylinder, the inner diameter of the ring is contacted with the rod, removing the pressure and pulling out the rod, and the three positive rings are integrated into a whole, and the middle holes are consistent. Conductive adhesive is coated on inner wall of steel cylinderThe contact points between the ring and the inner wall of the steel cylinder are more, and the conductivity is good; seventhly, pouring out the crushed powder in the steel cylinder, wiping the opening of the steel cylinder, weighing, and coating sealing glue on the opening of the steel cylinder; and step eight, inserting the rolled diaphragm tube into the center hole of the positive ring, rolling the diaphragm tube into a cylinder, and sealing the bottom. Firstly, rolling two layers of CN2000 negative electrode diaphragm, and then rolling two layers of SCIMAT 70035 positive electrode diaphragm, or one layer of each positive electrode diaphragm, or rolling 2-4 layers of other same diaphragm; ninth, adding 30-40% KOH aqueous solution into diaphragm tube to obtain electrolyte, allowing diaphragm and positive ring to absorb no-flow liquid, adding negative zinc paste, wherein the zinc paste is prepared by stirring Zn and/or ZnO, additive and binder, and has density of 2.5-3.5g/cm ³ (ii) a Inserting a negative current collector into the negative electrode zinc paste, wherein the negative current collector consists of a copper nail, a negative cover, a gasket and a sealing ring, the copper nail plated with In or Sn is welded with the negative cover, the gasket is placed In the sealing ring, and the copper nail is inserted into a hole In the gasket and the sealing ring to assemble a current collector; step ten, curling the steel cylinder, compressing the sealing ring longitudinally and transversely, sealing the battery and then sleeving the trademark to prepare a circleA column-type press-ring primary or secondary Zn-Ni battery.

The invention is characterized in that:

1. the invention adopts Ni (OH) ₂ Or NiOOH is used as the active substance of the positive electrode, and the pressing ring structure is adopted in the battery manufacturing process, so that the granulation process is added to improve the density of the powder of the positive electrode, and the density can be more than or equal to 1.7g/cm ³ Thus, the ring pressed by the powder has high density and large amount. The conductive material graphite is not well contacted with the positive active material in the granulation process, so that the internal resistance of the battery is reduced, and the prepared battery has high capacity.

Ni(OH) ₂ Or the particle size of the NiOOH anode active substance is generally about 10um, the particle size is too fine, the anode powder is easy to flow out from the die cavity without granulation in the process of pressing the ring, the more the anode powder flows out when the pressure is higher, the weight of the pressed anode ring is small, the powder flowing out is at the bottom and the edge of the ring pressing die,affecting the next ring formation. The positive electrode powder is adhered to the mold due to much moisture. The ring rolling machine has low rate of certified products and low efficiency. The particle size distribution and the moisture are controlled through the granulation process, so that the rate of graded products of the compression ring and the working efficiency are greatly improved.

2. The positive electrode of the cylindrical press ring type primary and secondary Zn-Ni battery is composed of three or four rings. When the rings are installed, the deviation is slightly generated, and the deviation of 0.01-0.03mm cannot be generated in the central holes of three or four rings, so that the diaphragm tube and the rings cannot be uniformly contacted, and the internal resistance of the battery is increased due to the gaps. After the electrolyte is added, because a gap is reserved between the diaphragm tube and the positive ring, the positive ring absorbs the electrolyte slowly, and the production process is prolonged. The invention adopts a re-pressing mode, and the holes in the three rings are consistent after re-pressing according to the inserted stick in the middle, which is beneficial to the close contact between the diaphragm pipe and the rings, reduces the internal resistance of the battery and shortens the electro-hydraulic absorption time.

3. The invention aims to improve the capacity of a Zn-Ni primary secondary battery during heavy current discharge, and the density of zinc paste is increased to 2.8-3.2g/cm ³ The cathode zinc paste amount can be increased, the conductivity between the zinc pastes is good, and the internal resistance of the battery is reduced.

4. The invention adopts two types of diaphragms to combine into a diaphragm tube, the diaphragm hole of the negative electrode is fine, the shelf life of the primary Zn-Ni battery can be prolonged, the cycle times of the secondary battery can be increased, and the deformation of the zinc negative electrode and the penetration of dendritic crystals can be prevented.

Drawings

FIG. 1 is a longitudinal sectional view of a Zn-Ni primary or secondary battery manufactured by the method of the present invention

In figure 1, a negative electrode cover 1, a copper nail 2, a sealing ring 3, a diaphragm tube 4, a negative electrode 5, a positive electrode 6, a steel cylinder 7 and a trademark 8 are arranged.

In figure 1, three rings (6) pressed by the granulated powder of the invention are placed in a steel cylinder (7) and are in tight contact with the inner wall of the steel cylinder, and a diaphragm tube (4) is inserted into a central hole of a positive ring (6). A paste negative electrode (5) is filled in the diaphragm tube (4), a negative electrode cover (1) and the copper nail (2) are welded and filled in the sealing ring (3) to assemble a negative electrode current collector, the negative electrode current collector is inserted into the negative electrode (5), and the negative electrode current is led out from the copper nail (2). The negative electrode cover (1) is the battery negative electrode terminal. The sealing ring (3) is matched with the steel cylinder (7) and sealed to form a semi-finished battery, and a trademark (8) is sleeved outside the semi-finished battery to form a finished battery.

Detailed Description

Example 1 preparation of model AA size primary Zn-Ni cell

Weighing 90g of self-made NiOOH powder, 10g of graphite powder, 1g of additive and 0.5g of binder, dry mixing for 20 minutes, wet mixing for 30 minutes according to the weight ratio of 38% KOH solution and 10g of KOH solution, tabletting the mixed powder on a roller press, wherein the tabletting thickness is 0.2-0.5 mm, crushing, tabletting and crushing, sieving with 40 meshes on an upper sieve and 80 meshes on a lower sieve. And storing the powder passing through the upper sieve and the powder not passing through the lower sieve in a sealing way. And crushing and sieving the powder which does not pass through the upper sieve. The powder passing through the lower sieve is tableted again and the process is repeated. The qualified powder was measured for particle size distribution and apparent specific gravity. Apparent specific gravity of 1.68g/cm ³ The granularity is 40-200 meshes, 40-60 meshes account for 5%,60-80 meshes account for 80%,80-100 meshes account for 10%, and 100-200 meshes account for 10%.

Weighing 3.55g of granulated qualified powder, pressing a ring to obtain a ring with the weight of 3.5g, the outer diameter phi of the ring being 13.24mm, the inner diameter phi of the ring being 9.04mm, the height of the ring being 14.1mm, and pressing 28 rings to form 27 rings. Accounting for 96 percent.

The ring is put into a steel cylinder repressing rolling groove, a diaphragm tube is inserted, liquid is added, zinc paste is added, a current collector is inserted, and the AA type battery label B is manufactured after sealing.

The powder with the same proportion is not easy to form without granulation and compression ring bonding and compression ring die, the electro-hydraulic fluid with the weight ratio of 38 percent KOH is changed into 6g, other components are not changed, the powder is not bonded and seriously leaked, 3.55g is weighed, the weight of the extruded ring is 2.9g, the outer diameter and the inner diameter of the ring are basically the same, and the ring height is 14.5mm. The ring strength is poor, 10 batteries which account for 50 percent are formed after 20 times of pressing and then are loaded into a steel cylinder, and only 1 AA type battery label C is made due to the ring strength difference after the re-pressing.

When the two batteries are discharged to 1.0V at a constant current of 500mA, the average capacity of the No. 2 battery is 1657.6mAh. The C cell is 852mAh.

Example 2 preparation of a AA size secondary Zn-Ni battery

By beta-Ni (OH) ₂ 90g of graphite powder, 10g of additive I2g of additive II1g of binder 0.5g, dry mixing for 20 minutes, adding 38% by weight of KOH solution 10g, wet mixing for 30 minutes, otherwise the same as in example 1. Weighing 2.8g of qualified granulated powder, pressing into rings with the weight of 2.7g and the height of 12mm, putting 3 rings into a steel cylinder for recompression, rolling a groove, inserting a diaphragm tube, adding liquid, adding zinc paste (mainly ZnO), inserting a negative electrode current collector to prepare the battery, charging with low current of 100mA, and discharging with constant current of 200mA to 1.0V. The capacity is about 800mAh after 3 times of charging and discharging.

The powder which is not granulated has poor ring strength, generates water after charging, and is loose and deformed.

The invention is not limited to AA size batteries, and is suitable for cylindrical press ring type Zn-Ni primary batteries and secondary batteries of all other specifications.

Claims

1. A method for preparing a cylindrical press ring type primary or secondary zinc-nickel battery is characterized by comprising the following steps: in the first step, ni (OH) is reacted with alpha-type or beta-type Ni ₂ Or gamma-type NiOOH or beta-type NiOOH is taken as the positive electrode active substance and is evenly mixed with the additive, the binder and the graphite; secondly, adding 30-40% KOH aqueous solution in a mist form into the uniformly mixed dry powder for wet mixing to obtain wet mixed powder; thirdly, tabletting, crushing and sieving the wet mixed powder to obtain anode powder in a granulation process; fourthly, pressing the anode powder into a circular ring type to obtain an anode ring; in the fifth step, the first step is carried out,three or four positive electrode rings are arranged in a nickel-plated steel cylinder together; sixthly, pressurizing and weighing the positive electrode ring, and performing secondary pressing to enable the positive electrode ring to be tightly contacted with the steel cylinder, so that the positive electrode ring is integrated; seventhly, coating sealing glue after the mouth of the steel cylinder is wiped clean and rolling a groove on the steel cylinder; eighthly, rolling the diaphragm into a cylinder, and inserting the bottom seal into the annular hole in a tubular shape; ninth, electrolyte absorption is carried out in the diaphragm tube, and zinc paste prepared from Zn or ZnO, additive and binder is added after no flowing electrolyte is added to serve as a negative electrode; step ten, inserting a negative electrode current collector into the negative electrode zinc paste, wherein the negative electrode current collector consists of a copper nail, a negative electrode cover, a gasket and a sealing ring; and the tenth step, sealing to prepare the cylindrical press ring type primary or secondary Zn-Ni battery.

2. The first step of the preparation process according to claim 1, characterized in that the NiOOH or Ni (OH) ₂ The ratio of the positive active substance to the graphite powder is 8-15: 1

3. The compressed tablet according to the third step of the production process of claim 1, wherein the wet blended powder is compressed by the roller for 1 to 3 times to form a tablet having a thickness of 0.2 to 2mm.

4. The third step of the process according to claim 1, wherein the pressed tablets are broken into small particles.

5. The third step of the preparation method according to claim 1, wherein the crushed small particles are passed through upper and lower vibrating sieves, the upper sieve is 14-20 mesh, the lower sieve is 60-100 mesh, and the positive electrode powder obtained is passed through the upper sieve but not passed through the lower sieve.

6. The positive electrode powder obtained in the third step of the production process according to claim 1, wherein the positive electrode powder has a density of 1.65 to 1.9g/cm ³ The granularity is between 14 meshes and 200 meshes, and the water content is 2-5 percent.

7. The positive electrode ring according to the fourth step of the production method of claim 1, wherein the density of the positive electrode ring is 2.5 to 3.6g/cm ³ 。

8. A steel cylinder according to the fifth step of the manufacturing method of claim 1, wherein the steel cylinder material is a 08F carbon steel plated with Ni, the outer layer is plated with Ni in a thickness of 2-4um, and the inner layer is plated with Ni in a thickness of 1-3um. The steel cylinder is a cylinder with the wall thickness of 0.2-0.35mm. And graphite conductive adhesive is coated on the inner wall of the steel cylinder.

9. The separator tube according to the eighth step of the production method of claim 1, wherein the separator tube comprises 2 to 4 layers, 1 to 2 layers comprise a positive electrode separator, SCIMAT (west yard) 70035, and the other 1 to 2 layers comprise a negative electrode separator CN2000, wherein the negative electrode separator is inside and the positive electrode separator is outside, and the separator tube can be wound by the same material.

10. The process according to claim 1, wherein the charged liquid in the ninth step is characterized in that the charged liquid is an aqueous solution having a KOH content of 30 to 40% by weight.

11. The calamine cream of the ninth step of the process of claim 1, wherein the density of the calamine cream is 2.8-3.2g/cm ³ 。

12. The negative electrode current collector according to the tenth preparation method of claim 1, wherein the negative electrode current collector is composed of a copper nail, a negative electrode cap, a gasket and a sealing ring, the copper nail and the negative electrode cap are welded and inserted into the central hole of the gasket and the central hole of the sealing ring, the copper nail is made of brass H62-68, and the surface of the copper nail is plated with In or Sn; the material of the negative electrode cover is 08F steel plated with Ni, and the thickness of the nickel plated layer is 2-4um; the gasket material is galvanized iron sheet or 08F steel plated with Ni; the sealing ring is made of polypropylene or nylon 66.

13. The production method according to claim 1, wherein the capacity ratio of the positive electrode active material to the negative electrode active material is 1: 1-2 for the primary Zn-Ni battery and 1: 1.5-3.5 for the secondary Zn-Ni battery.