Gel battery electrolyte and preparation method and application thereof

Abstract

The invention discloses gel battery electrolyte as well as a preparation method and application thereof. The gel battery electrolyte comprises silicon dioxide, a sulfuric acid electrolyte and a conductive carbon material, the conductive carbon material is selected from at least one of carbon nanotubes, carbon fibers, graphene and activated carbon. The problem that a large amount of silicon dioxide needs to be added in the gel electrolyte preparation process is solved, and the problems of low electrolyte conductivity and large internal resistance caused by the silicon dioxide are solved. The addition amount of silicon dioxide is reduced, the conductivity of the electrolyte is improved, and the electrochemical performance of the colloid lead-carbon battery is finally improved.

Description

Technical Field

[0001] The present application relates to a colloidal battery electrolyte and a preparation method and application thereof, belonging to the field of colloidal batteries. Background Art

[0002] Lead-carbon batteries consist of a negative electrode and a positive electrode. The active materials of the positive and negative electrodes are respectively composed of lead and lead dioxide, lead and lead sulfate. A separator is added between the positive and negative electrodes and immersed in liquid sulfuric acid electrolyte. It can be called a "liquid-filled lead-carbon battery". In addition, in order to reduce battery water loss and eliminate (or reduce) the need for regular maintenance, a sealed and maintenance-free "valve-regulated lead-carbon battery" has been developed.

[0003] Compared with traditional liquid-filled lead-carbon batteries, valve-regulated lead-acid batteries with gel electrolytes have excellent performance in many fields. This type of battery is also called a "colloidal lead-carbon battery". The key factor affecting the performance of colloidal lead-carbon batteries is the gel electrolyte itself.

[0004] There are many types of colloid gelling agents. Most gelling agents use precipitated silica, which has good viscosity and cycle stability during use, but it has many disadvantages, such as short coagulation time, high viscosity, high material and manufacturing costs, high internal resistance, etc. These disadvantages limit the widespread application of this type of battery. Moreover, silicon dioxide is an insulator, and the conductivity of the colloidal electrolyte it constitutes is too low. Compared with liquid electrolyte, the internal resistance of the colloidal electrolyte is larger, which is not conducive to the further development of battery performance. Summary of the invention

[0005] In order to solve the problem of needing to add a large amount of silicon dioxide during the preparation of the colloidal electrolyte and solve the problems of low electrolyte conductivity and large internal resistance caused by it, the present invention improves the electrochemical performance of the colloidal lead-carbon battery by adding a certain amount of conductive carbon material to the electrolyte of the colloidal lead-carbon battery. The addition of the conductive carbon material can effectively improve the conductivity of the colloidal electrolyte, reduce the internal resistance of the electrolyte, and improve the conductivity of the electrolyte, thereby ultimately improving the electrochemical performance of the colloidal lead-carbon battery.

[0006] According to one aspect of the present application, a colloidal battery electrolyte is provided, the colloidal battery electrolyte comprising silicon dioxide, sulfuric acid electrolyte, and conductive carbon material;

[0007] The conductive carbon material is selected from at least one of carbon nanotubes, carbon fibers, graphene, and activated carbon.

[0008] In the colloidal battery electrolyte, the mass fractions of each substance are:

[0009] 0.5-50 parts of silicon dioxide;

[0010] 5 to 98.5 parts of sulfuric acid in sulfuric acid electrolyte;

[0011] 0.01 to 10 parts of conductive carbon material.

[0012] Optionally, in the colloidal battery electrolyte, the mass fractions of each substance are:

[0013] 0.5-15 parts of silicon dioxide;

[0014] 20-50 parts of sulfuric acid in sulfuric acid electrolyte;

[0015] 0.1 to 10 parts of conductive carbon material.

[0016] The concentration of the sulfuric acid electrolyte is 1.05-1.5 g / ml.

[0017] According to another aspect of the present application, a method for preparing the above-mentioned colloidal battery electrolyte is provided, comprising the following steps:

[0018] The raw materials containing silicon dioxide, sulfuric acid electrolyte and conductive carbon material are mixed to obtain the colloidal battery electrolyte.

[0019] According to another aspect of the present application, a colloidal battery is provided, which uses the above-mentioned colloidal battery electrolyte.

[0020] The beneficial effects of this application include:

[0021] Reduce the amount of silicon dioxide added, increase the conductivity of the electrolyte, and ultimately improve the electrochemical performance of the colloidal lead-carbon battery. DETAILED DESCRIPTION

[0022] The present application is described in detail below with reference to embodiments, but the present application is not limited to these embodiments.

[0023] Example 1

[0024] Step 1: Prepare the colloidal battery electrolyte by the following method:

[0025] A colloidal electrolyte was prepared by fully mixing 10 g of silicon dioxide, 90 g of a sulfuric acid electrolyte having a mass fraction of 1.275 g / ml (the mass concentration of the sulfuric acid electrolyte was 37%, namely, the mass of pure sulfuric acid contained in the sulfuric acid solution was 33.3 g), and 1 g of carbon nanotubes.

[0026] Step 2: Prepare a colloidal lead-carbon battery by the following steps:

[0027] 1) Preparation of negative electrode: (1) Premix 600g lead powder, 9g activated carbon, 8.4g barium sulfate, and 0.3g polypropylene short fibers with a length of 5mm and a diameter of 0.5-1.5μm in a high-speed mixer, add 84g deionized water to the premixed powder while stirring, and continue stirring for 10 minutes to obtain lead paste; (2) Scrape the lead paste onto a metal lead grid with a size of 70mm long, 50mm wide, and 2mm thick, and cure and dry to obtain a lead-carbon battery negative electrode. The curing temperature is 40°C, the humidity is 80%, and the curing time is 20 hours; the drying temperature is 80°C, and the time is 24 hours;

[0028] 2) Preparation of the positive electrode: The positive electrode of the lead-acid battery is prepared according to the same process steps as the negative electrode preparation steps (1) and (2), except that no carbon material is added to the positive electrode;

[0029] 3) Preparation of lead-carbon battery: three positive plates and two negative plates are placed in parallel with each other in an alternating manner, and a colloidal PE separator for lead-carbon battery is placed between the positive plates and the negative plates, and two negative plates are welded in parallel and three positive plates are welded in parallel respectively. The total mass of positive active material of the lead-acid battery (the total mass of the lead paste on the three positive plates after drying) is 60.0g, and the total mass of positive active material refers to the total mass of the lead paste contained in the three positive plates welded in parallel. The total mass of negative active material (the total mass of the lead paste on the two negative plates after drying) is 52.9g, and the total mass of negative active material refers to the total mass of the lead paste contained in the two negative plates welded in parallel. The positive and negative electrode grids use conventional lead grids with dimensions of 70mm long, 50mm wide and 2mm thick; the positive and negative electrodes are placed in a tightly assembled battery box, where the battery box is 76mm long, 40mm wide and 100mm high, and 83g of the above-prepared colloidal electrolyte is injected into the battery box; after testing, the conductivity of the colloidal electrolyte between the positive and negative electrodes of the battery under this condition is 790mS / cm.

[0030] The battery was subjected to a normal temperature life test: 4.2A constant current discharge for 59 seconds, 18A discharge for 1 second, 6.3A current 2.3V voltage constant current constant voltage charge for 60 seconds, the charge and discharge conditions were cycled 3600 times, then left to stand for 40 hours, and then the cycle life test was continued after 40 hours. The termination condition of the life test was that the battery voltage dropped below 1.2V;

[0031] The initial voltage of the assembled internal hybrid battery at room temperature is 2.229V when fully charged, and the internal hybrid battery can run 47219 cycles in the room temperature life test. Compared with the test results of ordinary lead-acid batteries with the same lead content under the same test conditions (7201 cycles), the room temperature cycle life of the internal hybrid lead-carbon battery can reach 6.6 times that of traditional lead-acid batteries.

[0032] Example 2

[0033] According to the requirements of Example 1, without changing other conditions, the amount of carbon nanotubes added in step 1 was changed to 0.1g, the conductivity of the assembled internal hybrid battery colloidal electrolyte was 779mS / cm, the starting voltage was 2.22V under full charge at room temperature, and the assembled internal hybrid battery could run 46920 cycles in the room temperature life test. Compared with the test results of ordinary lead-acid batteries with the same lead content under the same test conditions (7201 cycles), the room temperature cycle life of the internal hybrid lead-carbon battery can reach 6.5 times the life of traditional lead-acid batteries.

[0034] Example 3

[0035] According to the requirements of Example 1, without changing other conditions, the amount of carbon nanotubes added in step 1 was changed to 10g, the conductivity of the assembled internal hybrid battery colloidal electrolyte was 783mS / cm, the starting voltage was 2.225V under full charge at room temperature, and the assembled internal hybrid battery could run 46203 cycles in the room temperature life test. Compared with the test results of ordinary lead-acid batteries with the same lead content under the same test conditions (7201 cycles), the room temperature cycle life of the internal hybrid lead-carbon battery can reach 6.4 times the life of traditional lead-acid batteries.

[0036] Example 4

[0037] According to the requirements of Example 1, without changing other conditions, the amount of silicon dioxide added in step 1 was changed to 0.5g, the conductivity of the assembled internal hybrid battery colloidal electrolyte was 765mS / cm, the starting voltage was 2.215V under full charge at room temperature, and the assembled internal hybrid battery could run 42583 cycles in the room temperature life test. Compared with the test results of ordinary lead-acid batteries with the same lead content under the same test conditions (7201 cycles), the room temperature cycle life of the internal hybrid lead-carbon battery can reach 5.9 times the life of traditional lead-acid batteries.

[0038] Example 5

[0039] According to the requirements of Example 1, without changing other conditions, the amount of silicon dioxide added in step 1 was changed to 50g, the conductivity of the assembled internal hybrid battery colloidal electrolyte was 757mS / cm, the starting voltage was 2.203V under full charge at room temperature, and the assembled internal hybrid battery could run 39721 cycles in the room temperature life test. Compared with the test results of ordinary lead-acid batteries with the same lead content under the same test conditions (7201 cycles), the room temperature cycle life of the internal hybrid lead-carbon battery can reach 5.5 times the life of traditional lead-acid batteries.

[0040] Example 6

[0041] According to the requirements of Example 1, without changing other conditions, the carbon nanotubes added in step 1 are replaced with graphene of equal mass, the conductivity of the assembled internal hybrid battery colloidal electrolyte is 795mS / cm, the starting voltage is 2.214V under normal temperature full charge state, and the assembled internal hybrid battery can run 46501 cycles in the normal temperature life test. Compared with the test results of ordinary lead-acid batteries with the same lead content under the same test conditions (7201 cycles), the normal temperature cycle life of the internal hybrid lead-carbon battery can reach 6.5 times the life of traditional lead-acid batteries.

[0042] Comparative Example 1

[0043] Lead-acid battery: According to the requirements of Example 1, without changing other conditions, step 2 "1) Preparation of negative electrode: (1) Premix 600g lead powder, 9g activated carbon, 8.4g barium sulfate, and 0.3g polypropylene staple fibers with a length of 5mm and a diameter of 0.5-1.5μm in a high-speed mixer, add 84g deionized water to the premixed powder while stirring, and continue stirring for 10min to obtain lead paste;" is changed to (without adding any carbon material) "1) Preparation of negative electrode: (1) Premix 600g lead powder, 9g activated carbon, 8.4g barium sulfate, and 0.3g polypropylene staple fibers with a length of 5mm and a diameter of 0.5-1.5μm in a high-speed mixer, add 84g deionized water to the premixed powder while stirring, and continue stirring for 10min to obtain lead paste;" and other steps remain unchanged to prepare a colloidal lead-acid battery. The conductivity of the assembled internal hybrid battery colloidal electrolyte is 677mS / cm. The starting voltage of the assembled internal hybrid battery when fully charged at room temperature is 2.131V, and it can run 7201 cycles in the room temperature life test.

[0044] Comparative Example 2

[0045] Lead-carbon battery: According to the requirements of Example 1, other conditions are not changed, and no conductive carbon material is added in the process of preparing the colloidal electrolyte in step 1. The conductivity of the assembled internal hybrid battery colloidal electrolyte is 669mS / cm, and the initial voltage of the assembled internal hybrid battery at room temperature and full charge is 2.116V, and it can run 10801 cycles in the room temperature life test. Due to the lack of the addition of conductive carbon material, the conductivity of the battery colloidal electrolyte is too low, which ultimately leads to poor battery cycle stability.

[0046] Comparative Example 3

[0047] According to the requirements of Example 1, without changing other conditions, the conductive carbon material added in step 1 is replaced with polyester fiber of equal mass, and the conductivity of the assembled internal hybrid battery colloid electrolyte is 602mS / cm, the starting voltage is 2.103V in the fully charged state at room temperature, and the assembled internal hybrid battery can run 9637 cycles in the room temperature life test. Since polyester fiber is not a conductive carbon material, it cannot improve the conductivity of the electrolyte, resulting in poor battery performance.

[0048] The above are only a few embodiments of the present application and do not constitute any form of limitation to the present application. Although the present application is disclosed as above with preferred embodiments, it is not intended to limit the present application. Any technician familiar with the profession, without departing from the scope of the technical solution of the present application, using the technical content disclosed above to make slight changes or modifications are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A colloidal battery electrolyte, characterized in that: The colloidal battery electrolyte includes silicon dioxide, sulfuric acid electrolyte, and conductive carbon material; The conductive carbon material is selected from at least one of carbon nanotubes, carbon fibers, graphene, and activated carbon.

2. The colloidal battery electrolyte according to claim 1, characterized in that: In the colloidal battery electrolyte, the mass fractions of each substance are: 0.5-50 parts of silicon dioxide; 5 to 98.5 parts of sulfuric acid in sulfuric acid electrolyte; 0.01 to 10 parts of conductive carbon material.

3. The colloidal battery electrolyte according to claim 1, characterized in that: In the colloidal battery electrolyte, the mass fractions of each substance are: 0.5-15 parts of silicon dioxide; 20-50 parts of sulfuric acid in sulfuric acid electrolyte; 0.1 to 10 parts of conductive carbon material.

4. The colloidal battery electrolyte according to claim 1, characterized in that: The concentration of the sulfuric acid electrolyte is 1.05-1.5 g / ml.

5. A method for preparing a colloidal battery electrolyte according to any one of claims 1 to 4, characterized in that: The following steps are involved: The raw materials containing silicon dioxide, sulfuric acid and conductive carbon material are mixed to obtain the colloidal battery electrolyte.

6. A colloidal battery, characterized in that: The colloidal battery electrolyte according to any one of claims 1 to 4 is used.