阅读说明：本技术 一种正极板栅用铅钙合金及其制备方法 (Lead-calcium alloy for positive grid and preparation method thereof ) 是由 魏慧献 邵双喜 于 2020-12-08 设计创作，主要内容包括：本发明公开了一种正极板栅用铅钙合金及其制备方法,由以下组分制成：钙,铝,锡,铋,稀土,改性石墨烯,余量为铅。本发明所述的正极板栅用铅钙合金具有良好的防腐蚀能力与抗拉强度,能够有效提高蓄电池的使用寿命；本发明通过控制铅钙合金中钙的含量在0.09%～0.096%能够显著提高防腐效果,其中钙含量为0.094%时,防腐效果最佳,当钙的含量大于0.096%时,在使用过程中,长宽方向长大速度增大,合金的腐蚀速度增加,从而降低电池使用寿命,当钙的含量小于0.09%时,合金内部结晶结构变粗,晶间腐蚀速度增加,正极板栅在使用过程中,会更快的出现腐烂、断裂,从而降低电池的使用寿命。(The invention discloses a lead-calcium alloy for a positive grid and a preparation method thereof, wherein the lead-calcium alloy is prepared from the following components: calcium, aluminum, tin, bismuth, rare earth, modified graphene and the balance of lead. The lead-calcium alloy for the positive grid has good corrosion resistance and tensile strength, and can effectively prolong the service life of a storage battery; according to the invention, the corrosion prevention effect can be obviously improved by controlling the calcium content in the lead-calcium alloy to be 0.09% -0.096%, wherein the corrosion prevention effect is optimal when the calcium content is 0.094%, when the calcium content is more than 0.096%, the growth speed in the length and width directions is increased and the corrosion speed of the alloy is increased in the use process, so that the service life of the battery is shortened, and when the calcium content is less than 0.09%, the internal crystal structure of the alloy is thickened, the intergranular corrosion speed is increased, and the positive grid can be quickly rotted and broken in the use process, so that the service life of the battery is shortened.)

1. The lead-calcium alloy for the positive grid is characterized by being prepared from the following components in percentage by weight: 0.09-0.096% of calcium, 0.01-0.05% of aluminum, 1.5-2% of tin, 0.08-0.12% of bismuth, 0.1-0.4% of rare earth, 0.08-0.2% of modified graphene and the balance of lead.

2. The lead-calcium alloy for the positive grid according to claim 1, wherein the lead-calcium alloy is prepared from the following components in percentage by weight: 0.092-0.096% of calcium, 0.01-0.03% of aluminum, 1.6-1.8% of tin, 0.09-0.12% of bismuth, 0.15-0.4% of rare earth, 0.1-0.2% of modified graphene and the balance of lead.

3. The lead-calcium alloy for the positive grid according to claim 1, wherein the lead-calcium alloy is prepared from the following components in percentage by weight: 0.094% of calcium, 0.02% of aluminum, 1.7% of tin, 0.1% of bismuth, 0.3% of rare earth, 0.12% of modified graphene and the balance of lead.

4. The lead-calcium alloy for the positive grid according to claim 1, wherein the rare earth consists of the following components in percentage by weight: 25-35% lanthanum, 20-30% yttrium, 20-30% neodymium, and 15-25% cerium.

5. The lead-calcium alloy for the positive grid according to claim 1, wherein the rare earth consists of the following components in percentage by weight: 32% lanthanum, 28% yttrium, 22% neodymium, 18% cerium.

6. The lead-calcium alloy for the positive grid according to claim 1, wherein the preparation method of the modified graphene comprises the following steps:

adding 1-4 parts of carbon nano tube into 15-25 parts of concentrated sulfuric acid, and stirring at the rotating speed of 80-200 rpm for 80-150 min to obtain a mixed solution;

adding 2-5 parts of graphene into 20-30 parts of deionized water, and uniformly dispersing to obtain a suspension; and adding the mixed solution and the suspension into a planetary ball mill for ball milling to obtain mixed slurry, carrying out ultrasonic treatment on the mixed slurry, and drying to obtain the modified graphene.

7. The lead-calcium alloy for the positive grid according to claim 6, wherein the planetary ball mill has a rotation speed of 200-400 rpm and a ball milling time of 2-5 h.

8. The lead-calcium alloy for positive grids according to claim 6, wherein the ultrasonic treatment power is 400-800W.

9. The preparation method of the lead-calcium alloy for the positive grid according to any one of claims 1 to 8, characterized by comprising the following steps:

adding part of lead into a smelting furnace, heating to 650-720 ℃ to melt the lead, adding calcium, stirring to melt the calcium, adding the rest lead, adding bismuth, aluminum, rare earth and tin, stirring to melt, cooling to 400-450 ℃, adding modified graphene, melting, and uniformly stirring to obtain the lead-calcium alloy for the positive grid.

10. The preparation method of the lead-calcium alloy for the positive grid according to claim 9, wherein the part of lead accounts for 58-70% of the weight of the formula.

Technical Field

The invention relates to the technical field of storage batteries, in particular to a lead-calcium alloy for a positive grid and a preparation method thereof.

Background

In the current industry, 70-80% of the reasons for the failure of lead-acid storage batteries are caused by the corrosion of positive grids. The grid is used as a carrier and a conductor of the lead plaster, the lead plaster is usually made of lead-calcium alloy, the lead plaster can become a polar plate only after being filled and coated on the grid and solidified and dried, the polar plate is the core of the lead storage battery, the grid is like a framework, the strength and the service life of the whole polar plate are directly influenced, and the corrosion of the lead-calcium alloy is one of important factors influencing the service life of the battery.

Chinese patent (103943866A) discloses an alloy grid for a storage battery, and specifically discloses an alloy grid for a storage battery, which comprises, by weight, 0.06% -0.12% of calcium, 0.2% -0.6% of tin, 0.02% -0.04% of aluminum, and the balance of lead. The production process is easy to cast and form, pollution-free, high in efficiency, free of influence on the performance of the tubular rich-liquid storage battery, and long in service life, and the prepared grid is not fragile. The closest comparison document of the invention solves the technical problems of easy casting and molding in production and no pollution, and does not indicate the influence of the addition amount of the single component on the whole formula system.

Chinese patent (CN 100355920C) discloses a grid alloy and a preparation method thereof, which particularly discloses that the grid alloy consists of calcium, aluminum, tin, silver and lead, and particularly discloses that the components of the grid alloy are as follows according to the weight unit half ratio: 0.1 to 0.2 parts of calcium, 0.03 to 0.05 parts of aluminum, 1.2 to 2 parts of tin, 0.001 to 0.025 parts of silver and the balance of lead, wherein the specification describes that: the addition of aluminum greatly reduces the amount of calcium oxide suspended in the cast grids and improves the mechanical properties with higher calcium utilization, while the mechanical properties and corrosion strength of the alloy are improved by the addition of silver, it can be seen that in the above patent, the addition of calcium is for the mechanical properties and the addition of silver is for the mechanical properties and the corrosion strength of the alloy, which also does not point out the effect of the addition of the individual components on the overall formulation system.

Disclosure of Invention

The invention provides a lead-calcium alloy for a positive grid and a preparation method thereof, which can effectively improve the corrosion resistance and tensile strength of the lead-calcium alloy, thereby prolonging the service life of the positive grid.

The invention adopts the following technical scheme for solving the technical problems:

the lead-calcium alloy for the positive grid is prepared from the following components in percentage by weight: 0.09-0.096% of calcium, 0.01-0.05% of aluminum, 1.5-2% of tin, 0.08-0.12% of bismuth, 0.1-0.4% of rare earth, 0.08-0.2% of modified graphene and the balance of lead.

The applicant of the present invention surprisingly discovers in research that, in the formula system of the present invention, the corrosion prevention effect can be significantly improved by controlling the calcium content in the lead-calcium alloy to be 0.09% -0.096%, wherein the corrosion prevention effect is the best when the calcium content is 0.094%, and when the calcium content is greater than 0.096%, the growth speed in the length and width direction is increased and the corrosion speed of the alloy is increased during the use process, so as to reduce the service life of the battery, and when the calcium content is less than 0.09%, the internal crystal structure of the alloy is coarsened, the intergranular corrosion speed is increased, and the positive grid is more rapidly decomposed and broken during the use process, so as to reduce the service life of the battery.

As a preferable scheme, the lead-calcium alloy is prepared from the following components in percentage by weight: 0.092-0.096% of calcium, 0.01-0.03% of aluminum, 1.6-1.8% of tin, 0.09-0.12% of bismuth, 0.15-0.4% of rare earth, 0.1-0.2% of modified graphene and the balance of lead.

As a most preferable scheme, the lead-calcium alloy is prepared from the following components in percentage by weight: 0.094% of calcium, 0.02% of aluminum, 1.7% of tin, 0.1% of bismuth, 0.3% of rare earth, 0.12% of modified graphene and the balance of lead.

As a preferable scheme, the rare earth consists of the following components in percentage by weight: 25-35% lanthanum, 20-30% yttrium, 20-30% neodymium, and 15-25% cerium.

The applicant of the invention finds that the electronegativity of lanthanum is 1.11, the electronegativity of yttrium is 1.22, the electronegativity of neodymium is 1.14, the electronegativity of cerium is 1.12, the electronegativity of the rare earth is 1.11-1.22, the electronegativity of the rare earth is greatly different from that of lead (electronegativity 1.8), the electronegativity of the rare earth is similar to that of calcium (electronegativity 1.0), and the rare earth tends to form a structure similar to that of Pb (Pb)₃In the solidification process, the intermediate compound of Ca can be precipitated on the surface of a grain boundary and the edge of the grain boundary to form a heterogeneous nucleation center, so that the nucleation energy is reduced, the nucleation rate in the crystallization solidification is increased, the alloy grain is refined, and the grain boundary is increased. The refined alloy grain structure can increase the obstruction of dislocation movement, realize the fine grain strengthening of the alloy, and further improve the mechanical property of the alloy.

In the formula system, the rare earth can improve hydrogen evolution overpotential and oxygen evolution overpotential of the lead-calcium alloy, inhibit oxygen evolution reaction on the surface of the alloy, and react with impurity elements to generate compounds, so that the impurity content in the lead-calcium alloy is reduced, the reduction of the hydrogen evolution overpotential caused by impurity introduction is avoided, the service life of a battery is prolonged, and a compact oxidation protection film can be formed on the surface of the lead alloy by adding the rare earth, so that the corrosion resistance of the alloy is obviously improved.

Meanwhile, the rare earth is added, so that holes on the corrosion film are distributed more uniformly, and the adhesion of active substances is facilitated.

As a most preferred scheme, the rare earth consists of the following components in percentage by weight: 32% lanthanum, 28% yttrium, 22% neodymium, 18% cerium.

As a preferable scheme, the preparation method of the modified graphene comprises the following steps:

adding 1-4 parts of carbon nano tube into 15-25 parts of concentrated sulfuric acid, and stirring at the rotating speed of 80-200 rpm for 80-150 min to obtain a mixed solution;

adding 2-5 parts of graphene into 20-30 parts of deionized water, and uniformly dispersing to obtain a suspension; and adding the mixed solution and the suspension into a planetary ball mill for ball milling to obtain mixed slurry, carrying out ultrasonic treatment on the mixed slurry, and drying to obtain the modified graphene.

The addition of the graphene into the lead-calcium alloy can increase the oxygen evolution overpotential of the lead-calcium alloy, inhibit the precipitation of oxygen and obviously improve the electrochemical performance and the corrosion resistance of the lead-calcium alloy, but the graphene cannot be uniformly dispersed in a metal matrix.

According to the invention, the modified graphene is obtained by modifying the graphene, the carbon nano tube and the graphene are compounded by modifying the graphene, so that the carbon nano tube and the graphene can be uniformly dispersed in the metal matrix and are compounded, the advantages of the carbon nano tube and the graphene can be fully exerted, the graphene can be effectively prevented from agglomerating, the crystal boundary becomes fuzzy by the modified graphene, the corrosion is prevented from going deep, and the corrosion resistance of the alloy is obviously improved.

As a preferable scheme, the rotating speed of the planetary ball mill is 200-400 rpm, and the ball milling time is 2-5 h.

As a preferred scheme, the ultrasonic treatment power is 400-800W.

The invention also provides a preparation method of the lead-calcium alloy for the positive grid, which comprises the following steps:

adding part of lead into a smelting furnace, heating to 650-720 ℃ to melt the lead, adding calcium, stirring to melt the calcium, adding the rest lead, adding bismuth, aluminum, rare earth and tin, stirring to melt, cooling to 400-450 ℃, adding modified graphene, melting, and uniformly stirring to obtain the lead-calcium alloy for the positive grid.

Through separately adding lead, and add earlier calcium before adding aluminium, tin, can make calcium and lead better alloying, can not lead to calcium to float on the lead liquid surface and by the oxidation loss of burning, aluminium can act as the covering agent, can prevent that lead calcium from contacting with the air and being oxidized at the surface film that the alloy fuse-element surface formed rich aluminium oxide, thereby can show improvement corrosion protection, improvement life.

As a preferable scheme, the part of lead accounts for 58-70% of the weight of the formula.

The invention has the beneficial effects that: (1) the lead-calcium alloy for the positive grid has good corrosion resistance and tensile strength, and can effectively prolong the service life of a storage battery; (2) according to the invention, the corrosion prevention effect can be obviously improved by controlling the content of the lead-calcium alloy to be 0.09% -0.096%, wherein the corrosion prevention effect is optimal when the calcium content is 0.094%, when the calcium content is more than 0.096%, the growth speed in the length and width directions is increased and the corrosion speed of the alloy is increased in the use process, so that the service life of the battery is reduced, when the calcium content is less than 0.09%, the internal crystal structure of the alloy is thickened, the intergranular corrosion speed is increased, and the positive grid can be quickly rotted and broken in the use process, so that the service life of the battery is reduced; (3) according to the invention, the lead is added separately, and the calcium is added before the aluminum and the tin are added, so that the calcium and the lead can be alloyed better, the calcium cannot float on the surface of the lead liquid and be oxidized and damaged, the aluminum can serve as a covering agent, an aluminum oxide-rich surface film can be formed on the surface of the alloy melt, the lead and the calcium are prevented from being oxidized due to contact with the air, the corrosion resistance can be obviously improved, and the service life is prolonged; (4) according to the invention, the corrosion resistance and the tensile strength are obviously improved by the rare earth and the modified graphene, wherein the addition of the rare earth is beneficial to the adhesion of the modified graphene, so that the corrosion resistance and the tensile strength are further improved.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are a part of the embodiments of the present invention, but not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the present invention, the "parts" are all parts by weight unless otherwise specified.

The graphene and the carbon nano tube are purchased from Suzhou carbon Feng graphene science and technology company, wherein the number of a graphene product is as follows: HQNANO-GR-011, carbon nanotube product number: HQNANO-CNTs-010.

Example 1

The lead-calcium alloy for the positive grid is prepared from the following components in percentage by weight: 0.094% of calcium, 0.02% of aluminum, 1.7% of tin, 0.1% of bismuth, 0.3% of rare earth, 0.12% of modified graphene and the balance of lead.

The rare earth comprises the following components in percentage by weight: 32% lanthanum, 28% yttrium, 22% neodymium, 18% cerium.

The preparation method of the modified graphene comprises the following steps:

adding 2 parts of carbon nano tube into 23 parts of concentrated sulfuric acid, and stirring at the rotating speed of 150rpm for 120min to obtain a mixed solution;

adding 4 parts of graphene into 21 parts of deionized water, and uniformly dispersing to obtain a suspension; and adding the mixed solution and the suspension into a planetary ball mill for ball milling to obtain mixed slurry, carrying out ultrasonic treatment on the mixed slurry, and drying to obtain the modified graphene.

The rotating speed of the planetary ball mill is 300rpm, and the ball milling time is 4 h.

The ultrasonic treatment power is 500W.

The preparation method of the lead-calcium alloy for the positive grid comprises the following steps:

adding 65% of lead in the formula weight into a smelting furnace, heating to 680 ℃ to melt the lead, adding calcium, stirring to melt the calcium, adding the rest lead, adding bismuth, aluminum, rare earth and tin, stirring to melt, cooling to 430 ℃, adding modified graphene, melting, and uniformly stirring to obtain the lead-calcium alloy for the positive grid.

Example 2

The lead-calcium alloy for the positive grid is prepared from the following components in percentage by weight: 0.09% of calcium, 0.01% of aluminum, 1.5% of tin, 0.08% of bismuth, 0.1% of rare earth, 0.08% of modified graphene and the balance of lead.

The rare earth comprises the following components in percentage by weight: 32% lanthanum, 28% yttrium, 22% neodymium, 18% cerium.

The preparation method of the modified graphene comprises the following steps:

adding 2 parts of carbon nano tube into 23 parts of concentrated sulfuric acid, and stirring at the rotating speed of 150rpm for 120min to obtain a mixed solution;

adding 4 parts of graphene into 21 parts of deionized water, and uniformly dispersing to obtain a suspension; and adding the mixed solution and the suspension into a planetary ball mill for ball milling to obtain mixed slurry, carrying out ultrasonic treatment on the mixed slurry, and drying to obtain the modified graphene.

The rotating speed of the planetary ball mill is 300rpm, and the ball milling time is 4 h.

The ultrasonic treatment power is 500W.

The preparation method of the lead-calcium alloy for the positive grid comprises the following steps:

adding 65% of lead in the formula weight into a smelting furnace, heating to 680 ℃ to melt the lead, adding calcium, stirring to melt the calcium, adding the rest lead, adding bismuth, aluminum, rare earth and tin, stirring to melt, cooling to 430 ℃, adding modified graphene, melting, and uniformly stirring to obtain the lead-calcium alloy for the positive grid.

Example 3

The lead-calcium alloy for the positive grid is prepared from the following components in percentage by weight: 0.096% of calcium, 0.05% of aluminum, 2% of tin, 0.12% of bismuth, 0.4% of rare earth, 0.2% of modified graphene and the balance of lead.

The rare earth comprises the following components in percentage by weight: 32% lanthanum, 28% yttrium, 22% neodymium, 18% cerium.

The preparation method of the modified graphene comprises the following steps:

adding 2 parts of carbon nano tube into 23 parts of concentrated sulfuric acid, and stirring at the rotating speed of 150rpm for 120min to obtain a mixed solution;

adding 4 parts of graphene into 21 parts of deionized water, and uniformly dispersing to obtain a suspension; and adding the mixed solution and the suspension into a planetary ball mill for ball milling to obtain mixed slurry, carrying out ultrasonic treatment on the mixed slurry, and drying to obtain the modified graphene.

The rotating speed of the planetary ball mill is 300rpm, and the ball milling time is 4 h.

The ultrasonic treatment power is 500W.

The preparation method of the lead-calcium alloy for the positive grid comprises the following steps:

adding 65% of lead in the formula weight into a smelting furnace, heating to 680 ℃ to melt the lead, adding calcium, stirring to melt the calcium, adding the rest lead, stirring to melt, adding aluminum and tin, stirring to melt, cooling to 430 ℃, adding modified graphene, melting, and uniformly stirring to obtain the lead-calcium alloy for the positive grid.

Example 4

The lead-calcium alloy for the positive grid is prepared from the following components in percentage by weight: 0.091% of calcium, 0.04% of aluminum, 1.6% of tin, 0.09% of bismuth, 0.2% of rare earth, 0.12% of modified graphene and the balance of lead.

The rare earth comprises the following components in percentage by weight: 32% lanthanum, 28% yttrium, 22% neodymium, 18% cerium.

The preparation method of the modified graphene comprises the following steps:

adding 2 parts of carbon nano tube into 23 parts of concentrated sulfuric acid, and stirring at the rotating speed of 150rpm for 120min to obtain a mixed solution;

adding 4 parts of graphene into 21 parts of deionized water, and uniformly dispersing to obtain a suspension; and adding the mixed solution and the suspension into a planetary ball mill for ball milling to obtain mixed slurry, carrying out ultrasonic treatment on the mixed slurry, and drying to obtain the modified graphene.

The rotating speed of the planetary ball mill is 300rpm, and the ball milling time is 4 h.

The ultrasonic treatment power is 500W.

The preparation method of the lead-calcium alloy for the positive grid comprises the following steps:

adding 65% of lead in the formula weight into a smelting furnace, heating to 680 ℃ to melt the lead, adding calcium, stirring to melt the calcium, adding the rest lead, adding bismuth, aluminum, rare earth and tin, stirring to melt, cooling to 430 ℃, adding modified graphene, melting, and uniformly stirring to obtain the lead-calcium alloy for the positive grid.

Comparative example 1

The difference between the comparative example 1 and the example 1 is that the proportion of the lead-calcium alloy in the comparative example 1 is different from that in the example 1, and the rest is the same.

The lead-calcium alloy for the positive grid is prepared from the following components in percentage by weight: 0.08% of calcium, 0.02% of aluminum, 1.7% of tin, 0.1% of bismuth, 0.3% of rare earth, 0.12% of modified graphene and the balance of lead.

Comparative example 2

Comparative example 2 is different from example 1 in that the lead-calcium alloy in comparative example 2 is different from example 1, and the rest is the same.

The lead-calcium alloy for the positive grid is prepared from the following components in percentage by weight: 0.1% of calcium, 0.02% of aluminum, 1.7% of tin, 0.1% of bismuth, 0.3% of rare earth, 0.12% of modified graphene and the balance of lead.

Comparative example 3

Comparative example 3 is different from example 1 in that the lead-calcium alloy in comparative example 3 is different from example 1, and the proportion is the same, i.e. rare earth is not contained in the comparative example.

The lead-calcium alloy for the positive grid is prepared from the following components in percentage by weight: 0.094% of calcium, 0.02% of aluminum, 1.7% of tin, 0.1% of bismuth, 0.12% of modified graphene and the balance of lead.

Comparative example 4

Comparative example 4 is different from example 1 in that the composition of rare earth described in comparative example 4 is different from that of example 1, and the others are the same.

The rare earth comprises the following components in percentage by weight: 32% of samarium, 28% of praseodymium, 22% of gadolinium and 18% of cerium.

Comparative example 5

Comparative example 5 is different from example 1 in that the lead-calcium alloy in comparative example 5 is different from example 1, and the proportion is the same, i.e. modified graphene is not contained in the comparative example.

The lead-calcium alloy for the positive grid is prepared from the following components in percentage by weight: 0.094% of calcium, 0.02% of aluminum, 1.7% of tin, 0.1% of bismuth and the balance of lead.

Comparative example 6

Comparative example 6 is different from example 1 in that graphene is used to replace modified graphene in the lead-calcium alloy described in comparative example 6, and the rest is the same.

The lead-calcium alloy for the positive grid is prepared from the following components in percentage by weight: 0.094% of calcium, 0.02% of aluminum, 1.7% of tin, 0.1% of bismuth, 0.3% of rare earth, 0.12% of graphene and the balance of lead.

Comparative example 7

Comparative example 7 is different from example 1 in that the modified graphene described in comparative example 7 is prepared by a method different from example 1, and the same is true in that the modified graphene used in comparative example 7 is modified by a surfactant-treated method

The preparation method of the modified graphene comprises the following steps:

adding 4 parts of graphene into 21 parts of sodium dodecyl benzene sulfonate, carrying out ultrasonic treatment at 500W for 30min, filtering, and drying to obtain the modified graphene.

To further demonstrate the effect of the present invention, the following test methods were provided:

1. anticorrosion tests, wherein the anticorrosion capacity of the lead-calcium alloy in examples 1 to 4 and comparative examples 1 to 7 (three are measured respectively, and an average value is taken) is tested by adopting a constant current corrosion weight loss method, and the experimental conditions are as follows: 0.3A/cm in 75 ℃ water area environment²The current of (2) was charged for 100 hours at constant current, and then compared by a weight loss method, and the test results are shown in table 1.

2. The tensile strength test is carried out according to GB/T228-2002, and the test results are shown in Table 1.

Table 1 results of performance testing

As can be seen from table 1, the lead-calcium alloy for the positive grid of the present invention has a good corrosion prevention effect and an excellent tensile strength.

As can be seen from comparison of examples 1 to 4, the proportion of different lead-calcium alloys can affect the corrosion prevention effect and tensile strength of the lead-calcium alloys, wherein example 1 is the best proportion.

It can be seen from the comparison of example 1 with comparative examples 1 and 2 that when the percentage content of calcium is out of the range described in the present invention, the corrosion prevention effect is significantly reduced, further, it is illustrated that when the content of calcium is greater than 0.096%, the length and width directions increase in speed and the corrosion rate of the alloy increases during use, thereby reducing the service life of the battery, and when the content of calcium is less than 0.09%, the internal crystal structure of the alloy becomes coarse, the intergranular corrosion rate increases, and the positive grid becomes rotten and broken during use more rapidly, thereby reducing the service life of the battery.

It is understood from the comparison of example 1 with comparative examples 3 and 4 that the rare earth of the present invention can significantly improve the corrosion prevention effect and the tensile strength, and in the present invention, the corrosion prevention effect and the tensile strength are reduced when the components of the rare earth are replaced.

Compared with the comparative examples 5 to 7, the modified graphene disclosed by the invention can obviously improve the anti-corrosion effect and the tensile strength, and compared with the graphene, the modified graphene disclosed by the invention can improve the anti-corrosion effect and the tensile strength, and compared with the common surfactant modification, the preparation method of the modified graphene disclosed by the invention can improve the anti-corrosion effect and the tensile strength.

In light of the foregoing description of preferred embodiments according to the invention, it is clear that many changes and modifications can be made by the person skilled in the art without departing from the scope of the invention. The technical scope of the present invention is not limited to the contents of the specification, and must be determined according to the scope of the claims.