Electrolyte for inhibiting circulating water loss of lead-carbon battery

Abstract

The invention discloses an electrolyte for inhibiting circulating water loss of a lead-carbon battery, and belongs to the technical field of lead-carbon battery electrolytes. The electrolyte is composed of a sulfuric acid solution, benzalacetone and L-cysteine; the addition amount of the benzalacetone is 0.005-0.015% of the mass of the sulfuric acid solution; the addition amount of the L-cysteine is 0.04-0.06% of the mass of the sulfuric acid solution; the mass percent of the sulfuric acid solution is 30-40%. L-cysteine in the electrolyte reduces the amount of metal active site binding water and strengthens a hydrogen bond network in water molecules; the benzalacetone can refine the crystal grains of lead sulfate, so that the lead sulfate crystal is more easily converted into lead in the charging process, and the hydrogen evolution side reaction is avoided. The benzalacetone and the L-cysteine are used as electrolyte additives to be applied to the electrolyte, so that the hydrogen evolution overpotential of a lead-carbon negative plate can be effectively and synergistically improved, and the gas evolution and the cycle water loss of the battery are reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of lead-carbon battery electrolyte, and in particular relates to an electrolyte capable of inhibiting cyclic water loss of a lead-carbon battery. Background Art

[0002] Lead-acid batteries are often cycled at a high rate partial state of charge (HRPSoC) during the driving of hybrid electric vehicles, which can easily lead to sulfation of the negative plate. In order to suppress this phenomenon, carbon additives need to be added to the negative plate. The addition of carbon materials can make the lead sulfate evenly distributed in the plate. The high specific surface area of ​​carbon can not only reduce the current density during charging and discharging, but also form a conductive network inside the plate, which is conducive to the transfer of electrons and improves the charging efficiency. However, since carbon materials have a lower hydrogen evolution overpotential than lead, the amount of hydrogen evolution and water loss of the battery at normal charging voltage increases. As the water content of the electrolyte gradually decreases, the increase in acid concentration will aggravate the corrosion of the grid, thereby aggravating the attenuation of the battery life. Summary of the invention

[0003] The object of the present invention is to provide an electrolyte for inhibiting water loss during the cycle of a lead-carbon battery, so as to solve the problem of water loss during the cycle of the lead-carbon battery in the background technology.

[0004] The purpose of the present invention can be achieved through the following technical solutions:

[0005] An electrolyte for inhibiting cyclic water loss of a lead-carbon battery, the electrolyte comprising a sulfuric acid solution, benzalkyne acetone and L-cysteine, wherein the amount of the benzalkyne acetone added is 0.005%-0.015% of the mass of the sulfuric acid solution; the amount of the L-cysteine ​​added is 0.04%-0.06% of the mass of the sulfuric acid solution;

[0006] As a further solution of the present invention, the mass percentage of the sulfuric acid solution is 30%-40%.

[0007] As a further solution of the present invention, the added amount of the benzalkyne acetone is 0.01% of the mass of the sulfuric acid solution.

[0008] As a further solution of the present invention, the amount of L-cysteine ​​added is 0.05% of the mass of the sulfuric acid solution.

[0009] As a further solution of the present invention, the mass percentage of the sulfuric acid solution is 37%.

[0010] A method for preparing an electrolyte for inhibiting cyclic water loss in a lead-carbon battery comprises the following steps:

[0011] Under stirring conditions, benzalkyne acetone is added to a sulfuric acid solution with a mass percentage of 30%-40%, and after mixing evenly, L-cysteine ​​is added and evenly dispersed to obtain an electrolyte; the amount of benzalkyne acetone added is 0.005%-0.015% of the mass of the sulfuric acid solution, and the amount of L-cysteine ​​added is 0.04%-0.06% of the mass of the sulfuric acid solution.

[0012] As a further solution of the present invention, the stirring speed is 100-300 rpm.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] The invention provides an electrolyte for inhibiting the cyclic water loss of a lead-carbon battery, which is composed of a sulfuric acid solution, benzalkyne acetone and L-cysteine. The polar groups amino (-NH2) and thiol (-SH) of the L-cysteine ​​in the electrolyte are adsorbed onto the surface of the negative electrode Pb metal, thereby reducing the amount of water bound to the metal active site and strengthening the hydrogen bond network in the water molecules. The introduction of benzalkyne acetone can refine the grains of lead sulfate, making it easier for these lead sulfate crystals to be converted into lead during the charging process, thereby avoiding the occurrence of hydrogen evolution side reactions. Applying benzalkyne acetone and L-cysteine ​​as electrolyte additives to the electrolyte can effectively and synergistically improve the hydrogen evolution overpotential of the lead-carbon negative plate and reduce gas evolution and battery cyclic water loss. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present invention will be further described below in conjunction with the accompanying drawings.

[0016] Figure 1 1 is an LSV curve diagram of the lead-carbon negative electrode of the present invention in the electrolyte of Comparative Example 1 and the electrolyte of Example 1;

[0017] Figure 2 10A discharge curve comparison diagram of the 6-DMF-25 experimental battery of the present invention in the electrolyte of Example 1 and Comparative Example 3;

[0018] Figure 3 The graphs are of the change in grams of water loss of the 6-DMF-25 experimental battery of the present invention in the electrolytes of Example 1 and Comparative Example 3 as the battery is cycled. DETAILED DESCRIPTION

[0019] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] An electrolyte for inhibiting cyclic water loss of a lead-carbon battery, the electrolyte comprising a sulfuric acid solution, benzalkyne acetone and L-cysteine, and a method for preparing the electrolyte comprising the following steps:

[0021] Under stirring condition of 100-300rpm, benzalkyne acetone is added to 30%-40% sulfuric acid solution by mass, mixed evenly, and then L-cysteine ​​is added and dispersed evenly to obtain electrolyte; the amount of benzalkyne acetone added is 0.005%-0.015% of the mass of the sulfuric acid solution, and the amount of L-cysteine ​​added is 0.04%-0.06% of the mass of the sulfuric acid solution.

[0022] Example 1

[0023] An electrolyte for inhibiting cyclic water loss of a lead-carbon battery, the electrolyte comprising a sulfuric acid solution, benzalkyne acetone and L-cysteine, and a method for preparing the electrolyte comprising the following steps:

[0024] Under stirring at 200 rpm, 0.0128 g of benzalkylacetone was added to 100 mL of 37% sulfuric acid solution (density of 1.28 g / mL, mass of 100 mL solution of 128 g), mixed evenly, and then 0.064 g of L-cysteine ​​was added and evenly dispersed to obtain an electrolyte.

[0025] Comparative Example 1

[0026] A lead-carbon battery electrolyte, the electrolyte consisting of a sulfuric acid solution and L-cysteine, and a method for preparing the electrolyte, comprising the following steps:

[0027] Under stirring at 200 rpm, 0.064 g of L-cysteine ​​was added to 100 mL of 37% sulfuric acid solution (density of 1.28 g / mL, mass of 100 mL solution of 128 g) and the electrolyte was obtained after uniform dispersion.

[0028] Comparative Example 2

[0029] An electrolyte for a lead-carbon battery, the electrolyte consisting of a sulfuric acid solution and benzalkyne acetone, and a method for preparing the electrolyte comprising the following steps:

[0030] Under stirring at 200 rpm, 0.0128 g of benzalkyneacetone was added to 100 mL of 37% sulfuric acid solution (density of 1.28 g / mL, mass of 100 mL solution of 128 g), and the mixture was mixed uniformly to obtain an electrolyte.

[0031] Comparative Example 3

[0032] A lead-carbon battery circulating electrolyte, wherein the electrolyte is 100 mL of a 37% by mass sulfuric acid solution (density is 1.28 g / mL).

[0033] The performance tests were performed on the electrolytes of Example 1 and Comparative Examples 1-3:

[0034] (I) Hg / Hg2SO4 is used as the reference electrode, the Pt sheet is used as the counter electrode, and the lead-carbon negative electrode plate is used as the working electrode. The electrolytes in Example 1 and Comparative Example 1 are used to form a three-electrode test system:

[0035] First, the lead-carbon negative electrode was activated for 24 hours in an electrochemical workstation, and then a cyclic voltammetry curve test was performed (scanning range was -1.5∽-0.2V, scanning speed was 5mV / s). After the scanning curve was stable, a hydrogen evolution LSV test was performed (scanning range was -1.5∽-1.1V, scanning speed was 5mV / s).

[0036] The test results are as follows Figure 1 As shown, Figure 1 is an LSV curve of a lead-carbon negative electrode in a sulfuric acid system electrolyte containing L-cysteine ​​(Comparative Example 1) and a lead-carbon negative electrode in a sulfuric acid system electrolyte containing benzalkyne acetone and L-cysteine ​​(Example 1), Figure 1 It can be seen that after the introduction of benzalkyne acetone, the gas evolution LSV curve of the carbon-containing negative electrode shifted negatively. 2 , the HER overpotential increased by 72 mV, indicating that the introduction of benzylidene acetone can effectively inhibit the generation of H2. The reason is that the introduction of benzylidene acetone can refine the lead sulfate grains, making these lead sulfate crystals easier to be converted into lead during the charging process, avoiding the occurrence of hydrogen evolution side reaction.

[0037] (ii) Take two groups of 6-DMF-25 lead-carbon dry batteries, add the electrolytes prepared in Example 1 and Comparative Examples 1-3 into 6-DMF-25 lead-carbon dry batteries respectively, adopt the same process for internal formation, and test the formed batteries by 100% DOD water bath cycle (eliminating the influence of external temperature changes on the batteries), and weigh the batteries after every 50 cycles to calculate the grams of water loss during the battery cycle.

[0038] The test results are shown in Table 1:

[0039] Table 1

[0040]

[0041] The test results of Example 1 and Comparative Example 3 are as follows Figure 2 and Figure 3 As shown, Figure 2 This is a comparison of 10A discharge curves of 6-DMF-25 experimental batteries in different electrolytes. Figure 3 The graph of the change of grams of water loss in the 6-DMF-25 experimental battery in different electrolytes as the cycle progresses; Figure 2 It can be seen that the discharge time of the battery containing the electrolyte of Comparative Example 3 is 152 min, and the discharge time of the battery containing the electrolyte of Example 1 is 156 min, indicating that the introduction of benzalkyne acetone and L-cysteine ​​will not have an adverse effect on the discharge capacity of the battery; Figure 3 It can be seen that by adding benzyl acetone and L-cysteine, the water loss grams of the battery during the cycle can be effectively reduced. Figure 1 The test results are consistent with those of the previous study, further proving the feasibility of using benzylidene acetone and L-cysteine ​​in actual electrolytes. In addition, according to the results in Table 1, benzylidene acetone and L-cysteine ​​have the potential to synergistically reduce the grams of water loss during battery cycles.

[0042] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0043] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An electrolyte for inhibiting cyclic water loss in a lead-carbon battery, characterized in that: The electrolyte consists of sulfuric acid solution, benzyl acetone and L-cysteine; The amount of benzalkyne acetone added is 0.005%-0.015% of the mass of the sulfuric acid solution; The amount of L-cysteine ​​added is 0.04%-0.06% of the mass of the sulfuric acid solution; The mass percentage of the sulfuric acid solution is 30%-40%.

2. The electrolyte for inhibiting cyclic water loss of lead-carbon batteries according to claim 1, characterized in that: The added amount of the benzalkyne acetone is 0.01% of the mass of the sulfuric acid solution.

3. The electrolyte for inhibiting cyclic water loss of lead-carbon batteries according to claim 1, characterized in that: The amount of L-cysteine ​​added is 0.05% of the mass of the sulfuric acid solution.

4. The electrolyte for inhibiting cyclic water loss of lead-carbon batteries according to claim 1, characterized in that: The mass percentage of sulfuric acid solution is 37%.

5. The electrolyte for inhibiting cyclic water loss of lead-carbon batteries according to claim 1, characterized in that: The method for preparing the electrolyte comprises the following steps: Under stirring conditions, benzalkyne acetone is added to a sulfuric acid solution with a mass percentage of 30%-40%, and after mixing evenly, L-cysteine ​​is added and evenly dispersed to obtain an electrolyte; the amount of benzalkyne acetone added is 0.005%-0.015% of the mass of the sulfuric acid solution, and the amount of L-cysteine ​​added is 0.04%-0.06% of the mass of the sulfuric acid solution.

6. The electrolyte for inhibiting cyclic water loss of lead-carbon batteries according to claim 5, characterized in that: The stirring speed is 100-300 rpm.

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