Composite carbon material and use thereof

Abstract

The application discloses a composite carbon material and application thereof. The battery sulfation problem and the problem of low hydrogen evolution overpotential of carbon material are solved by preparing the carbon composite material, the carbon composite material containing a mercapto group, an ether bond and a carboxyl group is prepared by blending and sintering of a mercapotolylene glycol carboxylic acid and a soluble lead salt, the C-O bond formed by the two ends of the ether bond and the O-Pb bond formed by the lead element and the carbon element are used as the crystal sites of lead atoms, the ether bond and the mercapto group can produce a synergistic effect, the combination energy of lead ions and sulfate radicals can be improved, the lead sulfate crystallization process can be effectively improved, the lead sulfate grains are refined, and the cycle life of the battery is prolonged. In addition, a large number of C-O-Pb bonds and mercapto groups can effectively occupy the hydrogen evolution active sites of the carbon material, the hydrogen evolution overpotential of the carbon material is improved, the hydrogen evolution amount in the use process of the lead-carbon battery is reduced, the consumption of the battery electrolyte is reduced, and the cycle life of the lead-carbon battery is further improved.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of composite carbon material and its application, belong to conductive material field. BACKGROUND

[0002] As a relatively early energy storage technology, lead-acid battery has a history of more than 160 years, based on its low cost, high safety and high recovery rate characteristics, such battery is widely used in large-scale long-time energy storage or hybrid electric vehicle (HEV) and electric vehicle (EV), however, in the working environment of HEV and EV, lead-acid battery is usually in partial state of charge mode, which will cause the accumulation of large lead sulfate crystal grains that cannot be eliminated by simple means in the negative electrode, and the problem of negative electrode sulfation, which greatly reduces the cycle life of the battery. To improve the cycle life of lead-acid battery in partial state of charge, researchers successfully developed lead-carbon battery by adding highly conductive activated carbon to the negative electrode of lead-acid battery. The addition of carbon material can improve the problem of negative electrode sulfation to some extent, but the low hydrogen evolution overpotential of carbon material also brings a large amount of hydrogen evolution problem to the battery. SUMMARY

[0003] The present application solves the problems of battery sulfation and low hydrogen evolution overpotential of carbon material by preparing a new type of carbon composite material for lead-carbon battery. The carbon composite material is made by blending and sintering mercapto polyethylene glycol carboxylic acid and soluble lead salt, obtaining a carbon composite material containing mercapto, ether bond and carboxyl. The C-O bond formed by the two ends of the ether bond with carbon element and the O-Pb bond formed with lead element use lead atom as crystal site, and the ether bond and mercapto can produce synergistic effect to improve the binding energy of lead ion and sulfate, which can effectively improve the lead sulfate crystallization process, refine the lead sulfate crystal grains and prolong the cycle life of the battery. In addition, a large number of C-O-Pb bonds and mercapto can effectively occupy the hydrogen evolution active sites of carbon material, improve the hydrogen evolution overpotential of carbon material, reduce the amount of hydrogen evolution during the use of lead-carbon battery, reduce the consumption of battery electrolyte, and further improve the cycle life of lead-carbon battery.

[0004] According to one aspect of the present application, a composite carbon material is provided, characterized in that,

[0005] The composite carbon material is obtained by the following steps:

[0006] Mixing mercapto polyethylene glycol carboxylic acid with lead salt, sintering to obtain the composite carbon material;

[0007] The composite carbon material contains mercapto, ether bond, C-O bond and C-Pb bond;

[0008] The mass content of Pb element in the composite carbon material is 1-40 wt%, and the mass content of O element is 1-40 wt%;

[0009] The specific surface area of the composite carbon material is 500-2500 m 2 / g.

[0010] The tap density of the composite carbon material is 1.2-3.0 g / cm 3 .

[0011] The molecular weight of the mercapto polyethylene glycol carboxylic acid is 500-50000;

[0012] The lead salt is selected from at least one of lead nitrate, lead chloride, and tetraethyl lead;

[0013] The mass ratio of the mercapto polyethylene glycol carboxylic acid to the lead salt is 10-0.1:1;

[0014] The mixing is performed by a ball milling method.

[0015] The sintering temperature is 500-1500℃;

[0016] The sintering time is 1-48 h.

[0017] The sintering atmosphere is a mixed atmosphere containing hydrogen and an inactive gas;

[0018] The inactive gas is selected from at least one of nitrogen, helium, and argon;

[0019] The flow ratio of the inactive gas to the hydrogen is 100-0.01:1;

[0020] The ratio of the total mass of the mercapto polyethylene glycol carboxylic acid and the lead salt to the total volume of the gas passed during the sintering process is 1 g:0.001-200 L.

[0021] According to another aspect of the present application, an electrode containing the above composite carbon material is provided.

[0022] According to another aspect of the present application, a lead-acid battery containing the above electrode is provided.

[0023] The beneficial effects that can be produced by the present application include:

[0024] The application solves the problems of battery sulfation and low hydrogen evolution overpotential of carbon material by preparing a new type of carbon composite material for lead-carbon battery, which is prepared by blending and sintering mercapto polyethylene glycol carboxylic acid and soluble lead salt, obtaining carbon composite material containing mercapto, ether bond and carboxyl, using C-O bond formed by ether bond at both ends with carbon element and O-Pb bond formed with lead element to take lead atom as crystal site, and ether bond and mercapto can produce synergistic effect to improve the combination energy of lead ion and sulfate radical, which can effectively improve the lead sulfate crystallization process, refine the lead sulfate grain, and prolong the cycle life of the battery. In addition, a large number of C-O-Pb bonds and mercapto can effectively occupy the hydrogen evolution active sites of carbon material, improve the hydrogen evolution overpotential of carbon material, reduce the amount of hydrogen evolution during the use of lead-carbon battery, reduce the consumption of battery electrolyte, and further improve the cycle life of lead-carbon battery. DETAILED DESCRIPTION

[0025] The application will be described in detail below in conjunction with examples.

[0026] Unless otherwise specified, the raw materials in the examples are commercially purchased and directly used without treatment; the instruments and equipment used are used with the recommended parameters of the manufacturers.

[0027] In the examples, the cycle life of the lead-carbon battery is tested by using Blue Power charge-discharge instrument and Xinwei charge-discharge tester.

[0028] In the examples, the existence of mercapto, ether bond-O-, C-O bond and C-Pb bond in the carbon material and the mass proportion of each element atom in the tested sample are obtained by infrared test (FT-IR) and X-ray photoelectron spectroscopy analysis (XPS) test.

[0029] Example 1

[0030] Step one: the following method is used to prepare the composite carbon material:

[0031] First, 10g of mercapto polyethylene glycol carboxylic acid with a molecular weight of 1000 and 10g of lead nitrate are fully mixed by high-speed ball milling, and then the mixture powder is transferred to an 800-degree Celsius nitrogen-hydrogen mixed gas for full sintering, wherein the flow ratio of nitrogen to hydrogen is 95:5, and the sintering time is 8 hours. It is tested that the prepared carbon material contains mercapto, ether bond-O-, C-O bond and C-Pb bond, and the atomic mass of Pb element accounts for 20% of the total mass of the tested sample, the atomic mass of oxygen element accounts for 20% of the total mass of the tested sample, the specific surface area is 1100m 2 / g, and the tap density is 1.6g / cm 3 .

[0032] Step two: the following method is used to prepare lead-carbon battery electrode and lead-carbon battery and test the cycle stability and gas evolution amount:

[0033] 1) Preparation of negative electrode: (1) 600 g of lead powder, 9 g of the prepared carbon material, 8.4 g of barium sulfate, and 0.3 g of polypropylene short fibers with a length of 5 mm and a diameter of 0.5-1.5 μm were premixed with a high-speed mixer, and 84 g of deionized water was added to the premixed powder while stirring, and the stirring was continued for 10 min to obtain a lead paste; (2) the lead paste was coated onto a metal lead grid with a size of 70 mm in length, 50 mm in width, and 2 mm in thickness, and the grid was cured and dried to obtain a lead-carbon battery negative electrode. The curing temperature was 40 °C, the humidity was 80%, and the curing time was 20 hours; the drying temperature was 80 °C, and the time was 24 hours;

[0034] 2) Preparation of positive electrode: the lead-acid battery positive electrode was prepared according to the same process steps as steps (1) and (2) for the preparation of the negative electrode, except that no carbon material was added to the positive electrode;

[0035] 3) Preparation of lead-carbon battery: three positive electrode plates and two negative electrode plates were placed in parallel in sequence with an interval, and a gel lead-carbon battery PE separator was placed between the positive and negative electrode plates. The two negative electrode plates were connected in parallel and welded, and the three positive electrode plates were connected in parallel and welded. The total mass of the positive electrode active material (the total mass of the lead paste after drying on the three positive electrode plates) was 60.0 g, the total mass of the negative electrode active material (the total mass of the lead paste after drying on the two negative electrode plates) was 52.9 g, and the lead-acid battery positive electrode grid was a conventional lead grid with a size of 70 mm in length, 50 mm in width, and 2 mm in thickness. The positive and negative electrodes were placed in a tightly assembled battery box with a size of 76 mm in length, 40 mm in width, and 100 mm in height, and 83 g of sulfuric acid electrolyte with a mass concentration of 1.275 g / ml prepared above was injected into the battery box;

[0036] The battery was subjected to normal temperature life test under the following conditions: 4.2 A constant current discharge for 59 seconds, 18 A discharge for 1 second, 6.3 A current and 2.3 V voltage constant current and constant voltage charging for 60 seconds, and the above charging and discharging conditions were cycled 3600 times, followed by 40 hours of standing, and the cycle was restarted after 40 hours. The termination condition of the life test was that the battery voltage decreased to below 1.2 V. The assembled internal mixing type battery could run 54631 cycles in the normal temperature life test. Compared with the test results of the ordinary lead-acid battery with the same lead content under the same test conditions (7200 cycles), the normal temperature cycle life of the assembled lead-carbon battery could reach 7.6 times the life of the traditional lead-acid battery.

[0037] The battery is subjected to normal temperature gas emission amount test, and the test method is as follows: the battery is fully sealed with commercial paraffin wax, then a gas guide pipe is inserted at the exhaust port of the battery, the end of the gas guide pipe in the battery passes through the length of 5mm of the rubber plug, the end of the gas guide pipe outside the working electrode chamber is introduced into the device for testing the volume of gas by drainage method, and the inner and outer surfaces of the rubber plug and the various connections between the gas guide pipe and the commercial drainage method gas volume measuring device are sealed firmly with commercial AB glue, so as to ensure that the gas generated from the battery end is completely introduced into the commercial drainage method gas volume measuring device, the device is used to collect the gas volume generated from the battery end, and the gas generation rate is calculated, during the test, the battery system is placed in a constant temperature environment of 25℃, a constant voltage of 2.4V is applied to the battery for 48 hours, and the gas generation rate of the lead-carbon battery of the carbon material of the formula is 0.18ml / (wh·h) after calculation.

[0038] Example 2

[0039] According to the requirements of example 1, without changing other conditions, the addition amount of mercapto polyethylene glycol carboxylic acid in step one is changed to 1g, and after testing, the prepared carbon material contains mercapto, ether bond-O-, C-O bond and C-Pb bond, and the atomic mass of Pb element accounts for 30% of the total mass of the tested sample, and the atomic mass of oxygen element accounts for 10% of the total mass of the tested sample. The specific surface area of the prepared carbon composite material is 1163m 2 / g, the tap density is 2.2g / cm 3 , and the assembled internal mixing type battery can run for 52256 times in normal temperature life test. Compared with the test results of ordinary lead-acid battery with the same lead element content under the same test conditions (7200 times), the normal temperature cycle life of the internal mixing lead-carbon battery can reach 7.3 times of the life of the traditional lead-acid battery. The gas generation rate of the assembled lead-carbon battery in the room temperature environment is 0.17ml / (wh·h).

[0040] Example 3

[0041] According to the requirements of example 1, without changing other conditions, the addition amount of mercapto polyethylene glycol carboxylic acid in step one is changed to 100g, and after testing, the prepared carbon material contains mercapto, ether bond-O-, C-O bond and C-Pb bond, and the atomic mass of Pb element accounts for 10% of the total mass of the tested sample, and the atomic mass of oxygen element accounts for 40% of the total mass of the tested sample. The specific surface area of the prepared carbon composite material is 1043m 2 / g, the tap density is 2.5g / cm 3, the assembled internal mixing type battery can run 56527 cycles in normal temperature life test. Compared with the test results of ordinary lead-acid batteries with the same lead element content under the same test conditions (7200 cycles), the normal temperature cycle life of the internal mixing lead-carbon battery can reach 7.9 times the life of the traditional lead-acid battery. The gas production rate of the assembled lead-carbon battery in a room temperature environment is 0.27 ml / (wh·h).

[0042] Example 4

[0043] According to the requirements of Example 1, without changing other conditions, the flow ratio of nitrogen to hydrogen in step one is replaced by 50:50. The test shows that the prepared carbon material contains sulfydryl, ether bond -O-, C-O bond and C-Pb bond, and the atomic mass of Pb element accounts for 10% of the total mass of the tested sample, the atomic mass of oxygen element accounts for 30% of the total mass of the tested sample, the specific surface area of the prepared carbon composite material is 1984 m 2 / g, the tap density is 2.9 g / cm 3 , the assembled internal mixing type battery can run 48150 cycles in normal temperature life test. Compared with the test results of ordinary lead-acid batteries with the same lead element content under the same test conditions (7200 cycles), the normal temperature cycle life of the internal mixing lead-carbon battery can reach 6.7 times the life of the traditional lead-acid battery. The gas production rate of the assembled lead-carbon battery in a room temperature environment is 0.20 ml / (wh·h).

[0044] Example 5

[0045] According to the requirements of Example 1, without changing other conditions, the flow ratio of nitrogen to hydrogen in step one is replaced by 5:95. The test shows that the prepared carbon material contains sulfydryl, ether bond -O-, C-O bond and C-Pb bond, and the atomic mass of Pb element accounts for 5% of the total mass of the tested sample, the atomic mass of oxygen element accounts for 40% of the total mass of the tested sample, the specific surface area of the prepared carbon composite material is 1732 m 2 / g, the tap density is 1.8 g / cm 3 , the assembled internal mixing type battery can run 38777 cycles in normal temperature life test. Compared with the test results of ordinary lead-acid batteries with the same lead element content under the same test conditions (7200 cycles), the normal temperature cycle life of the internal mixing lead-carbon battery can reach 5.4 times the life of the traditional lead-acid battery. The gas production rate of the assembled lead-carbon battery in a room temperature environment is 0.25 ml / (wh·h).

[0046] Example 6

[0047] According to the requirements of Example 1, without changing other conditions, the sintering temperature of step one is changed to 600 degrees Celsius. The prepared carbon material contains sulfydryl, ether bond -O-, C-O bond and C-Pb bond, and the atomic mass of Pb element accounts for 25% of the total mass of the tested sample, the atomic mass of oxygen element accounts for 15% of the total mass of the tested sample, the specific surface area of the prepared carbon composite material is 1456 m 2 / g, the tap density is 2.8 g / cm 3 The assembled internal mixing type battery can run 41948 times in normal temperature life test. Compared with the test results of ordinary lead-acid battery with the same lead element content under the same test conditions (7200 times), the normal temperature cycle life of the internal mixing lead-carbon battery can reach 5.8 times of the life of the traditional lead-acid battery. The gas production rate of the assembled lead-carbon battery in a room temperature environment is 0.21 ml / (wh·h).

[0048] Example 7

[0049] According to the requirements of Example 1, without changing other conditions, the sintering temperature of step one is changed to 1100 degrees Celsius. The prepared carbon material contains sulfydryl, ether bond -O-, C-O bond and C-Pb bond, and the atomic mass of Pb element accounts for 30% of the total mass of the tested sample, the atomic mass of oxygen element accounts for 20% of the total mass of the tested sample, the specific surface area of the prepared carbon composite material is 1873 m 2 / g, the tap density is 2.6 g / cm 3 The assembled internal mixing type battery can run 25503 times in normal temperature life test. Compared with the test results of ordinary lead-acid battery with the same lead element content under the same test conditions (7200 times), the normal temperature cycle life of the internal mixing lead-carbon battery can reach 3.5 times of the life of the traditional lead-acid battery. The gas production rate of the assembled lead-carbon battery in a room temperature environment is 0.26 ml / (wh·h).

[0050] Example 8

[0051] According to the requirements of Example 1, without changing other conditions, the sulfydryl polyethylene glycol carboxylic acid with a molecular weight of 1000 in step one is replaced by the same mass of sulfydryl polyethylene glycol carboxylic acid with a molecular weight of 50000. The prepared carbon material contains sulfydryl, ether bond -O-, C-O bond and C-Pb bond, and the atomic mass of Pb element accounts for 25% of the total mass of the tested sample, the atomic mass of oxygen element accounts for 25% of the total mass of the tested sample, the specific surface area of the prepared carbon composite material is 1934 m 2 / g, the tap density is 1.9 g / cm 3The assembled internal mixing type battery can run 26629 cycles in the normal temperature life test. Compared with the test results of the ordinary lead-acid battery with the same lead element content under the same test conditions (7200 cycles), the normal temperature cycle life of the internal mixing lead-carbon battery can reach 3.7 times the life of the traditional lead-acid battery. The gas production rate of the assembled lead-carbon battery in a room temperature environment is 0.29 ml / (wh·h).

[0052] Comparative Example 1

[0053] Lead-acid battery: according to the requirements of Example 1, without changing other conditions, changing step two "1) Preparation of negative electrode: (1) 600 g of lead powder, 9 g of prepared carbon material, 8.4 g of barium sulfate, and 0.3 g of polypropylene short fiber with a length of 5 mm and a diameter of 0.5-1.5 μm were pre-mixed with a high-speed mixer. While stirring, 84 g of deionized water was added to the pre-mixed powder, and stirring was continued for 10 min to obtain lead paste;" to "(without adding any carbon material) 1) Preparation of negative electrode: (1) 600 g of lead powder, 8.4 g of barium sulfate, and 0.3 g of polypropylene short fiber with a length of 5 mm and a diameter of 0.5-1.5 μm were pre-mixed with a high-speed mixer. While stirring, 84 g of deionized water was added to the pre-mixed powder, and stirring was continued for 10 min to obtain lead paste;" other steps were unchanged, and the preparation of the lead-acid battery was carried out. The assembled internal mixing type battery can run 7200 cycles in the normal temperature life test. The lead-acid battery has no hydrogen evolution problem, so the gas production rate test is not performed.

[0054] Comparative Example 2

[0055] Lead-carbon battery: according to the requirements of Example 1, without changing other conditions, without preparing composite carbon material, directly using activated carbon with a specific surface area of 1300 m 2 / g as a carbon material additive for lead-carbon battery, the assembled internal mixing type battery can run 10800 cycles in the normal temperature life test. The gas production rate of the assembled lead-carbon battery in a room temperature environment is 0.40 ml / (wh·h).

[0056] Comparative Example 3

[0057] According to the requirements of Example 1, without changing other conditions, the amount of mercapto polyethylene glycol carboxylic acid in step one is changed to 0.1 g. The carbon material prepared contains mercapto groups, ether bonds -O-, C-O bonds and C-Pb bonds, but the atomic mass of Pb element accounts for 80% of the total mass of the tested sample, and the atomic mass of oxygen element accounts for 0.5% of the total mass of the tested sample. Due to the high proportion of Pb element and the low proportion of -O- bond in the prepared carbon material, stable C-O-Pb bonds cannot be formed, and Pb element cannot effectively inhibit the hydrogen evolution of carbon material. The assembled internal mixing type battery can run 6452 times in the normal temperature life test. The gas production rate of the assembled lead-carbon battery in the room temperature environment is 0.51 ml / (wh·h). The specific surface area of the prepared carbon composite material is 40 m 2 / g, and the tap density is 1.2 g / cm 3 .

[0058] Comparative Example 4

[0059] According to the requirements of Example 1, without changing other conditions, the mercapto polyethylene glycol carboxylic acid in step one is replaced with equal mass of n-butanol. The carbon material prepared does not contain mercapto groups, ether bonds -O-, C-O bonds and C-Pb bonds, and cannot form stable C-O-Pb bonds. Pb element cannot effectively inhibit the hydrogen evolution of carbon material. The assembled internal mixing type battery can run 5356 times in the normal temperature life test. The gas production rate of the assembled lead-carbon battery in the room temperature environment is 0.91 ml / (wh·h). The specific surface area of the prepared carbon composite material is 500 m 2 / g, and the tap density is 1.5 g / cm 3 .

[0060] Comparative Example 5

[0061] According to the requirements of Example 1, without changing other conditions, the sintering temperature in step one is changed to 300 degrees Celsius. Due to the low sintering temperature, the thermodynamic conditions for generating the target carbon material cannot be met, and the battery test cannot be completed.

[0062] Comparative Example 6

[0063] According to the requirements of Example 1, without changing other conditions, the sintering temperature of step one is changed to 2000 degrees Celsius. Due to the high sintering temperature, the graphitization degree of the carbon material is not good, and a large amount of metallic lead is reduced. The prepared carbon material contains sulfhydryl, ether bond -O-, C-O bond and C-Pb bond, but the atomic mass of Pb element accounts for 70% of the total mass of the tested sample, and the atomic mass of oxygen element accounts for 0.5% of the total mass of the tested sample. Due to the high proportion of Pb element in the prepared carbon material and the low proportion of -O- bond, stable C-O-Pb bond cannot be formed, and Pb element cannot effectively inhibit the hydrogen evolution of carbon material. The assembled internal mixing type battery can run 2834 times in the normal temperature life test. The gas production rate of the assembled lead-carbon battery in the room temperature environment is 0.93 ml / (wh·h). The specific surface area of the prepared carbon composite material is 20 m 2 / g, and the tap density is 1.7 g / cm 3 .

[0064] Comparative Example 7

[0065] According to the requirements of Example 1, without changing other conditions, the sulfhydryl polyethylene glycol carboxylic acid in step one is replaced by polyethylene glycol dicarboxylic acid with the same molecular weight. The prepared carbon material does not contain sulfhydryl, contains ether bond -O-, C-O bond and C-Pb bond, the atomic mass of Pb element accounts for 30% of the total mass of the tested sample, and the atomic mass of oxygen element accounts for 20% of the total mass of the tested sample. Since the prepared carbon material does not contain sulfhydryl, it cannot achieve the best effect of improving the crystallization of lead sulfate grains, and the assembled internal mixing type battery can run 8528 times in the normal temperature life test. The gas production rate of the assembled lead-carbon battery in the room temperature environment is 0.49 ml / (wh·h). The specific surface area of the prepared carbon composite material is 1200 m 2 / g, and the tap density is 1.3 g / cm 3 .

[0066] Comparative Example 8

[0067] According to the requirements of Example 1, without changing other conditions, the sulfhydryl polyethylene glycol carboxylic acid in step one is replaced by sulfhydryl oxalic acid with the same mass. The prepared carbon material does not contain ether bond -O-, contains sulfhydryl, C-O bond and C-Pb bond, the atomic mass of Pb element accounts for 15% of the total mass of the tested sample, and the atomic mass of oxygen element accounts for 15% of the total mass of the tested sample. Since the prepared carbon material does not contain ether bond, it cannot achieve the best effect of improving the crystallization of lead sulfate grains, and the assembled internal mixing type battery can run 7963 times in the normal temperature life test. The gas production rate of the assembled lead-carbon battery in the room temperature environment is 0.54 ml / (wh·h). The specific surface area of the prepared carbon composite material is 1200 m 2 / g, and the tap density is 1.4 g / cm 3 .

[0068] Comparative Example 9

[0069] According to the requirements of Example 1, without changing other conditions, the ball milling process of step one was changed to disperse each reactant precursor in an aqueous solution, and after sufficient drying, sintering was performed to prepare a carbon composite material. Due to the lack of a ball milling process, although the prepared carbon material contained sulfhydryl groups, ether bonds -O-, C-O bonds, and C-Pb bonds, the characteristic peak of the C-Pb bond was very weak, the atomic mass of the Pb element accounted for 0.5% of the total mass of the tested sample, and the atomic mass of the oxygen element accounted for 20% of the total mass of the tested sample. The optimal effect of improving lead sulfate grain crystallization could not be achieved, and the assembled internal mixing type battery could run for 9035 cycles in the normal temperature life test. The gas production rate of the assembled lead-carbon battery in a room temperature environment was 0.61 ml / (wh·h). The specific surface area of the prepared carbon composite material was 1100 m 2 / g, and the tap density was 1.1 g / cm 3 .

[0070] Analyzing the experimental results of the above examples and comparative examples, it can be concluded that the prepared composite carbon material can only achieve the best effect on the cycle life of the battery when it simultaneously has sulfhydryl groups, ether bonds -O-, C-O bonds, and C-Pb bonds, and the bond strength of each bond is relatively strong.

[0071] The above is only a few embodiments of the present application, and does not limit the present application in any form. Although the preferred embodiments are disclosed as above, they are not intended to limit the present application. Any skilled person in the art can make some changes or modifications to the above disclosed technical content without departing from the scope of the technical solutions of the present application, and such changes or modifications are equivalent to equivalent embodiments, which are within the scope of the technical solutions.

Claims

1.A composite carbon material for lead-carbon battery, characterized in that, the composite carbon material is obtained by the following steps: mixing a mercapto polyethylene glycol carboxylic acid with a lead salt, sintering to obtain the composite carbon material; the composite carbon material contains mercapto group, ether bond, C-O bond and C-Pb bond; the mass content of Pb element in the composite carbon material is 1-40wt%, and the mass content of O element is 1-40wt%; The specific surface area of the composite carbon material is 500-2500 m 2 / g; The tap density of the composite carbon material is 1.2-3.0 g / cm 3 . 2.The composite carbon material for lead-carbon battery according to claim 1, characterized in that, the molecular weight of the mercapto polyethylene glycol carboxylic acid is 500-50000; the lead salt is selected from at least one of lead nitrate, lead chloride and tetraethyl lead; the mass ratio of the mercapto polyethylene glycol carboxylic acid to the lead salt is 10-0.1:1; the mixing is carried out by ball milling. 3.The composite carbon material for lead-carbon battery according to claim 1, characterized in that, the sintering temperature is 500-1500℃; the sintering time is 1-48h. 4.The composite carbon material for lead-carbon battery according to claim 1, characterized in that, the sintering atmosphere is a mixed atmosphere containing hydrogen and non-active gas; the non-active gas is selected from at least one of nitrogen, helium and argon; the flow ratio of the non-active gas to the hydrogen is 100-0.01:1; the ratio of the total mass of the mercapto polyethylene glycol carboxylic acid and the lead salt to the total volume of the gas passing through during the sintering process is 1g:0.001-200L. 5.An electrode, characterized in that, containing the composite carbon material for lead-carbon battery according to any one of claims 1-4. 6.A lead-acid battery, characterized in that, containing the electrode according to claim 5.