CN110571433A - A kind of negative electrode carbon additive and application thereof to improve charge acceptance of lead-carbon battery - Google Patents

Abstract

The invention discloses a negative electrode carbon additive for improving the charge acceptability of lead-carbon batteries, and belongs to the technical field of lead-acid battery production. Among many biomass materials, rice husk contains up to 20% nano-scale silica. Most of the nano-scale silica on the epidermis was removed by alkali treatment of rice husk and then carbonized to obtain a rice husk-based porous carbon dominated by macropores/mesopores. The macropore and mesopore structure of rice husk-based porous carbon can provide good ion conductors for energy storage devices and improve the kinetic activity of electrochemical reactions. The rice husk-based porous carbon is uniformly mixed with one or more of activated carbon, carbon black, graphite, expanded graphite, graphene, single-walled carbon nanotubes, multi-walled carbon nanotubes, etc., to further enhance the conductivity of the negative electrode carbon additive. This carbon additive for the negative electrode of the lead-carbon battery can effectively improve the charge acceptance of the lead-carbon battery, inhibit the sulfation of the negative electrode of the partial state of charge (PSoC) lead-acid battery and prolong the cycle life of the battery in PSoC.

Description

A kind of negative electrode carbon additive and application thereof to improve charge acceptance of lead-carbon battery

technical field

The invention belongs to the technical field of lead-acid battery production, and relates to a negative electrode carbon additive for improving the charging acceptance capacity of lead-carbon batteries.

Background technique.

Based on good safety, reliability and mature manufacturing recycling technology, lead-acid batteries occupy an irreplaceable important position in the field of energy storage. Emerging energy storage markets such as hybrid vehicles and renewable energy storage have grown their share year by year. These areas of energy storage require lead-acid batteries to be in partial state of charge (PSoC) for extended periods of time. The negative electrode of the lead-acid battery that has been in PSoC for a long time is gradually sulfated, resulting in a decrease in the battery's charge acceptance and battery failure. Studies have shown that the application of carbon additives in negative electrode active materials can effectively inhibit sulfation and improve the cycle life of lead-acid batteries under PSoC conditions.

Chinese patent 200910227199.0 discloses a new type of lead-carbon battery and its manufacturing method, and emphasizes the effect of carbon additives with high specific surface area (1000-3000m ² g ^-1 ) on the energy density and power density of lead-carbon batteries. Chinese patent 201210371066.2 discloses a lead-carbon battery negative plate, emphasizing the buffering effect of activated carbon additives with high specific surface area (1000-3000m ² g ^-1 ) on high current charge and discharge. The preparation process of this activated high-surface carbon material is complex and costly. Chinese patent 201610522472.2 discloses a modified carbon material, its preparation method, negative electrode paste, plate and lead-carbon battery. The carbon additive can inhibit hydrogen evolution, improve battery capacity and high rate charge and discharge performance. This patent aims to recycle and reuse biomass materials, and fails to make full use of the porous structure characteristics of biomass materials.

Contents of the invention

In order to improve the charge acceptance of the lead-carbon battery and prolong the cycle life of the battery under PSoC conditions, the technical problem to be solved by the present invention is to provide a negative electrode carbon additive that improves the charge acceptance of the lead-carbon battery. The main component of the carbon additive is rice husk-based porous carbon mainly composed of macropores and mesopores obtained through alkali treatment and simple carbonization preparation process. The macropore and mesopore structure of rice husk-based porous carbon can provide good ion conductors for energy storage devices and improve the kinetic activity of electrochemical reactions. The rice husk-based porous carbon is uniformly mixed with one or more of activated carbon, carbon black, graphite, expanded graphite, graphene, single-walled carbon nanotubes, multi-walled carbon nanotubes, etc., to further enhance the conductivity of the negative electrode carbon additive. Using this mixed carbon material containing rice husk-based porous carbon as the carbon additive of the negative electrode of the lead-carbon battery can effectively improve the charge acceptance of the lead-carbon battery and inhibit the sulfation of the negative electrode of the partial state of charge (PSoC) lead-acid battery. , and extend battery cycle life in PSoC.

In the first aspect, the present invention provides a negative electrode carbon additive for improving the charge acceptance of lead-carbon batteries. The specific preparation steps are as follows:

(1) Wash the rice husk, add 10-50wt.% alkali solution, react at a temperature of 90-150°C for 1-10h, the mass ratio of the rice husk to alkali is 1:1-10, filter, and purify Washing with water and drying to obtain desiliconized rice husk;

(2) carbonizing the desiliconized rice husk obtained in the above step (1) in a closed environment at 300-1000° C., crushing and classifying to obtain rice husk-based porous carbon;

(3) The rice husk-based porous carbon obtained in the above step (2) is uniformly mixed with one or more of activated carbon, carbon black, graphite, expanded graphite, graphene, single-walled carbon nanotubes, and multi-walled carbon nanotubes, wherein rice The total mass ratio of the shell-based porous carbon is 10%-100%, and a negative electrode carbon additive for improving the charging acceptance capacity of the lead-carbon battery is obtained.

The alkali solution described in the step (1) is one or a mixed solution of potassium hydroxide, sodium hydroxide, and other medium-strong alkali solutions.

The rice husk-based porous carbon in the step (2) is neutral or weakly alkaline, and the pH is 7-9.

The particle size D ₅₀ of the rice husk-based porous carbon classified in step (2) is less than or equal to 10 μm, the specific surface area is 100-1200 m ² g ^-1 , and the pore volume is 0.05-1.0 cm ³ g ^-1 .

In the negative electrode carbon additive described in step (3) to improve the charge acceptance of the lead-carbon battery, the preferred percentage of the total mass of the rice husk-based porous carbon is 50%-80%.

The negative electrode carbon additive is used for the negative electrode paste of the lead-carbon battery, and the raw materials of the negative electrode paste of the lead-carbon battery are composed of: 100 parts of lead powder, 0.1-0.2 parts of short fiber, 0.6-1.4 parts of barium sulfate, humic acid 0.1-0.4 parts, 0.1-0.4 parts of sodium lignosulfonate, 0.1-0.4 parts of acetylene black, 0.1-60 parts of the negative electrode carbon additive, 4-50 parts of sulfuric acid, and 12-30 parts of water.

The negative electrode paste of the lead-carbon battery is used for the negative electrode plate of the lead-carbon battery. The negative electrode paste of the lead-carbon battery is used as a raw material, and the lead-carbon battery containing the lead-carbon battery is improved according to the conventional paste and curing process. Negative lead paste coating and solidification of the negative carbon additive to prepare the negative plate.

In the negative plate of the lead-carbon battery, the active material of the negative plate maintains a high specific surface area of 0.6-10m ² g ^-1 and a porosity of 0.008-0.150cm ³ g ^-1 during the charging and discharging process.

The application of the negative electrode plate in the lead-carbon battery is to assemble and form the lead-carbon battery negative plate, the positive plate, the diaphragm and the electrolyte according to the battery technology, and obtain the lead-carbon battery with improved charge acceptance.

Beneficial effects: the present invention has the advantages that the rice husk-based porous carbon with macropore and mesoporous structure as the main structure is prepared by using the unique natural structural characteristics of rice husk through alkali treatment and carbonization. The macropore and mesopore structure of rice husk-based porous carbon can provide good ion conductors for energy storage devices and improve the kinetic activity of electrochemical reactions. The rice husk-based porous carbon is uniformly mixed with one or more of activated carbon, carbon black, graphite, expanded graphite, graphene, single-walled carbon nanotubes, multi-walled carbon nanotubes, etc., to further enhance the conductivity of the negative electrode carbon additive. Using this mixed carbon material containing rice husk-based porous carbon as the negative electrode carbon additive of lead-carbon batteries can maintain a high specific surface area (0.6-10m ² g ^-1 ) and porosity ( 0.008-0.150cm ³ g ^-1 ), effectively improve the charge acceptance of lead-carbon batteries, inhibit the sulfation of the negative electrode of partial state of charge (PSoC) lead-acid batteries, and prolong the cycle life of batteries in PSoC, realizing this purpose of the invention.

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

Description of drawings

Figure 1 is the discharge curves of the lead-carbon battery and the control battery at different current densities containing the negative electrode carbon additive that improves the charge acceptance of the lead-carbon battery.

Figure 2 shows the cycle life of lead-carbon batteries and control batteries containing negative carbon additives that improve the charge acceptance of lead-carbon batteries in accelerated battery aging tests.

Detailed ways

Below in conjunction with example the present invention will be further described.

Example 1:

(1) Wash 10 g of rice husk, react in 200 mL, 30 wt.% sodium hydroxide solution at 100° C. for 2 h, filter, wash with purified water, and dry to obtain a desiliconized rice husk;

(2) After the desiliconized rice husk obtained in the above step (1) is carbonized in a closed environment at 600° C., it is crushed and classified to obtain rice husk-based porous carbon.

(3) The rice husk-based porous carbon obtained in the above step (2) is directly used as a negative electrode carbon additive to improve the charging acceptance capacity of lead-carbon batteries.

Weigh 1Kg of lead powder, 1.3g of short fiber, 8g of barium sulfate, 2.5g of humic acid, 2.5g of sodium lignosulfonate, 1.8g of acetylene black and 10g of negative electrode carbon additive to improve the charge acceptance of lead-carbon batteries, and dry mix them 30min, then quickly add 110mL of pure water, stir for 10min, slowly add 60mL of 51.5wt.% sulfuric acid solution and stir for 30min, apply the prepared lead paste on the lead-calcium alloy grid, and cure at 50°C and 90% humidity for 24 After 1 hour, it was cured for 24 hours at 60° C. and 80% humidity, and then dried to obtain a negative electrode plate.

After the obtained pole plate is externalized, it is covered with a separator, and _two externally formed PbO2 positive electrodes are assembled into a lead-carbon battery in a 1.28g/mL sulfuric acid electrolyte.

Example 2:

(1) Wash 10g of rice husk, react in 200mL, 35wt.% sodium hydroxide solution at 95°C for 1.5h, filter, wash with purified water, and dry to obtain a desiliconized rice husk;

(2) Carbonize the desiliconized rice husk obtained in the above step (1) in a closed environment at 650° C., and then pulverize and classify to obtain rice husk-based porous carbon.

(3) The rice husk-based porous carbon and graphite obtained in the above step (2) are uniformly mixed in a ratio of 8:3 to obtain a negative electrode carbon additive that improves the charge acceptance of lead-carbon batteries.

Weigh 1Kg of lead powder, 1.3g of short fiber, 8g of barium sulfate, 2.5g of humic acid, 2.5g of sodium lignosulfonate, 1.5g of acetylene black and 10g of negative electrode carbon additive to improve the charge acceptance of lead-carbon batteries, and dry mix them After 30min, quickly add 115mL of pure water, stir for 10min, slowly add 57mL of sulfuric acid solution (51.5wt.%) and stir for 30min, and apply the prepared lead paste on the lead-calcium alloy grid, at 50°C and 90% humidity After curing for 24 hours, cure for 24 hours at 60° C. and 80% humidity, and dry to obtain a negative electrode plate.

After the obtained pole plate is externalized, it is covered with a separator, and _two externally formed PbO2 positive electrodes are assembled into a lead-carbon battery in a 1.28g/mL sulfuric acid electrolyte.

Example 3:

(1) Wash 10g of rice husk, react in 200mL, 30wt.% potassium hydroxide solution at 90°C for 2.5h, filter, wash with purified water, and dry to obtain a desiliconized rice husk;

(2) Carbonize the desiliconized rice husk obtained in the above step (1) in a closed environment at 700° C., and then pulverize and classify to obtain rice husk-based porous carbon.

(3) The rice husk-based porous carbon obtained in the above step (2), conductive carbon black and graphite are uniformly mixed in a ratio of 7:2:3 to obtain a negative electrode carbon additive that improves the charge acceptance of lead-carbon batteries.

Weigh 1Kg of lead powder, 1.3g of short fiber, 8g of barium sulfate, 2g of humic acid, 2g of sodium lignosulfonate, 1.3g of acetylene black and 12g of negative electrode carbon additives for improving the charge acceptance of lead-carbon batteries, and dry-mix for 30min. Then quickly add 118mL of primary water, stir for 10min, slowly add 58mL of sulfuric acid solution (51.5wt.%) and stir for 30min, coat the prepared lead paste on the lead-calcium alloy grid, and cure in 50°C and 90% humidity environment After 24 hours, cure for 24 hours at 60° C. and 80% humidity, and dry to obtain a negative electrode plate.

After the obtained pole plate is externalized, it is covered with a separator, and _two externally formed PbO2 positive electrodes are assembled into a lead-carbon battery in a 1.28g/mL sulfuric acid electrolyte.

The experiment also assembled a battery with no carbon additive in the negative electrode as a control battery.

The above-mentioned batteries were tested for different rate current discharge capacity and cycle life performance. The same charging method is adopted for the sample battery, and the discharge capacity of different rate currents is shown in Figure 1. The discharge specific capacity of the sample battery 1C ₁ in Examples 1, 2, and 3 is 8.7%, 18.7%, and 31.2% higher than that of the control battery, respectively. In the cycle life test of the sample batteries, as shown in Figure 2, the discharge capacities of the sample batteries of Examples 1, 2, and 3 at cycle 170 are 26.7%, 36.7%, and 45.3% higher than that of the control battery, respectively.

Claims (9)

1. A negative electrode carbon additive for improving the charge acceptance of a lead-carbon battery is characterized in that: the preparation steps are as follows:

(1) Cleaning rice hulls, adding 10-50 wt.% of alkali solution, reacting at 90-150 ℃ for 1-10h, wherein the mass ratio of the rice hulls to the alkali is 1:1-10, filtering, washing with purified water, and drying to obtain desiliconized rice hulls;

(2) Carbonizing the desiliconized rice hulls obtained in the step (1) in a closed environment at 300-1000 ℃, and crushing and grading to obtain rice hull-based porous carbon;

(3) And (3) uniformly mixing the rice hull-based porous carbon obtained in the step (2) with one or more of activated carbon, carbon black, graphite, expanded graphite, graphene, single-walled carbon nanotubes and multi-walled carbon nanotubes, wherein the rice hull-based porous carbon accounts for 10-100% of the total mass ratio, and thus obtaining the negative electrode carbon additive for improving the charge acceptance of the lead-carbon battery.

2. The negative electrode carbon additive for improving the charge acceptance of the lead-carbon battery according to claim 1, wherein the alkali solution in the step (1) is one or a mixed solution of potassium hydroxide, sodium hydroxide and other moderately strong alkali solutions.

3. The negative electrode carbon additive for improving the charge acceptance of the lead-carbon battery according to claim 1, wherein the rice hull-based porous carbon in the step (2) is neutral or weakly alkaline, and has a pH of 7-9.

4. The negative electrode carbon additive for improving the charge acceptance of the lead-carbon battery according to claim 1, wherein the rice hull-based porous carbon particle size D obtained after the grading treatment in the step (2)₅₀Less than or equal to 10 μm, and specific surface area of 100-1200m²g^-1Pore volume of 0.05-1.0cm³g^-1。

5. The negative electrode carbon additive for improving the charge acceptance of the lead-carbon battery as claimed in claim 1, wherein the preferred percentage of the rice husk-based porous carbon in the negative electrode carbon additive to the total mass is 50% -80%.

6. The use of the negative carbon additive for improving the charge acceptance of a lead-carbon battery according to claim 1, wherein: the negative lead plaster for the lead-carbon battery comprises the following raw materials: 100 parts of lead powder, 0.1-0.2 part of short fiber, 0.6-1.4 part of barium sulfate, 0.1-0.4 part of humic acid, 0.1-0.4 part of sodium lignosulfonate, 0.1-0.4 part of acetylene black, 0.1-60 parts of negative carbon additive, 4-15 parts of 51.5 wt.% sulfuric acid solution and 8-20 parts of water.

7. The use of the negative carbon additive for improving the charge acceptance of a lead-carbon battery as claimed in claim 6, wherein: the negative lead plaster of the lead-carbon battery is used for a negative pole plate of the lead-carbon battery, the negative lead plaster of the lead-carbon battery is used as a raw material, and the negative lead plaster containing the negative carbon additive for improving the charge acceptance of the lead-carbon battery is coated and cured according to the conventional coating and curing process of the storage battery to prepare the negative pole plate.

8. The use of the negative carbon additive for improving the charge acceptance of a lead-carbon battery as claimed in claim 7, wherein: the active substance of the negative plate of the lead-carbon battery maintains higher specific surface area of 0.6-10m in the charge and discharge processes²g^-1And a porosity of 0.008-0.150cm³g^-1。

9. The use of the negative carbon additive for improving the charge acceptance of a lead-carbon battery according to claim 7 or 8, wherein: the negative electrode plate is applied to the lead-carbon battery, and the negative electrode plate, the positive electrode plate, the diaphragm and the electrolyte of the lead-carbon battery are assembled and formed according to a storage battery process to obtain the lead-carbon battery with improved charging acceptance.