Lead-tin-cobalt-silver alloy for high-temperature-resistant long-life valve-controlled lead-acid storage battery and preparation method therefor

Abstract

A lead-tin-cobalt-silver alloy for a high-temperature-resistant long-life valve-controlled lead-acid storage battery and a preparation method therefor, relating to the technical field of lead-acid storage batteries. The Pb-Sn-Co-Ag alloy comprises the following alloy components: Pb with a mass fraction of 97%–99%; Sn with a mass fraction of 1.20%–1.80%; Co with a mass fraction of 0.18%–0.3%; and Ag with a mass fraction of 0.12%–0.15%.

Description

High temperature resistant life valve regulated lead acid battery lead tin cobalt silver alloy and preparation method thereof TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of lead-acid batteries, in particular, to a high temperature resistant life valve regulated lead acid battery lead tin cobalt silver alloy and preparation method thereof. BACKGROUND

[0002] Valve regulated lead acid battery is composed of positive plate, negative plate, electrolyte, separator, battery tank, exhaust valve and other main components. Valve regulated battery does not need to be maintained by adding water, is equipped with a one-way exhaust valve, and when the internal pressure of the battery is too high, the valve opens to discharge gas, external gas does not enter the internal battery, and has the function of absorbing oxygen at the negative electrode. This kind of battery is maintenance-free, which is called VRLA battery. The grid alloy used in the production of valve regulated lead acid battery is mainly Pb-Ca-Sn-Al alloy, and the battery can work under the condition of-40℃ to 60℃.

[0003] At present, the grid alloy type of valve regulated lead acid battery used in lawn mower is Pb-Ca-Sn-Al alloy. When the battery on the lawn mower is charged and discharged in a high temperature environment greater than 60℃, the positive grid is oxidized to PbSO4 and PbO2 during the charging process, and the water loss generated by the charging of the battery at high temperature increases the density of the electrolyte, accelerates the corrosion of the grid, and finally leads to the loss of the supporting effect of the active material by the grid, resulting in rapid failure of the battery. In order to improve the high temperature life of the battery, Sn, Co and Ag are added to the positive and negative grid alloys of VRLA battery in a suitable proportion, which can effectively improve the corrosion resistance of the grid, improve the mechanical properties and electrochemical properties of the grid alloy, reduce the water loss during the charging process of the battery, and improve the service life of the battery under the condition of 75℃ high temperature. Therefore, how to solve the problems existing in the prior art is the research subject of the present application.

[0004] APPLICATION CONTENT

[0005] In order to achieve the above purpose, the technical scheme of the present application is as follows: a high temperature resistant life valve regulated lead acid battery lead tin cobalt silver alloy, namely Pb-Sn-Co-Ag alloy, comprises the following alloy components:

[0006] Pb mass fraction is 97% to 99%;

[0007] Sn mass fraction is 1.20% to 1.80%;

[0008] Co mass fraction is 0.18% to 0.3%;

[0009] Ag mass fraction is 0.12% to 0.15%.

[0010] As an improvement of the present application, the Pb-Sn-Co-Ag alloy comprises a positive electrode Pb-Sn-Co-Ag alloy, the positive electrode Pb-Sn-Co-Ag alloy comprises the following alloy components, the mass fraction of Pb is 97.8%±0.5%, the mass fraction of Sn is 1.70%±0.05%, the mass fraction of Co is 0.25%±0.02%, and the mass fraction of Ag is 0.14%±0.02%.

[0011] As an improvement of the present application, the Pb-Sn-Co-Ag alloy comprises a negative electrode Pb-Sn-Co-Ag alloy, the negative electrode Pb-Sn-Co-Ag alloy comprises the following alloy components, the mass fraction of Pb is 98.4%±0.5%, the mass fraction of Sn is 1.20%±0.05%, the mass fraction of Co is 0.18%±0.02%, and the mass fraction of Ag is 0.12%±0.02%.

[0012] As an improvement of the present application, the Pb-Sn-Co-Ag alloy further comprises Ca, and the mass fraction of Ca is 0.025%-0.085%.

[0013] As an improvement of the present application, the Pb-Sn-Co-Ag alloy further comprises Al, and the mass fraction of Al is 0.025%±0.002%.

[0014] As an improvement of the present application, the mass fraction of Ca in the positive electrode Pb-Sn-Co-Ag alloy is 0.080%±0.002%, and the mass fraction of Ca in the negative electrode Pb-Sn-Co-Ag alloy is 0.090%±0.002%.

[0015] As an improvement of the present application, the mass fraction of Al in the positive electrode Pb-Sn-Co-Ag alloy is 0.025%±0.002%, and the mass fraction of Al in the negative electrode Pb-Sn-Co-Ag alloy is 0.030%±0.002%.

[0016] As an improvement of the present application, a preparation method of a high-temperature-resistant service life valve-regulated lead-acid battery lead-tin-cobalt-silver alloy comprises the following steps:

[0017] Step S1, electrolytic lead is added to a lead melting pot in proportion and heated;

[0018] Step S2, after the electrolytic lead is melted, stirring is performed, tin ingots are added in proportion and heated and stirred, cobalt ingots are added and heated and dissolved and stirred, and silver ingots are added and heated and dissolved and stirred;

[0019] Step S3, the Ca-Al alloy is broken into small pieces, wrapped with paper, and put into a bell with holes, directly under the molten lead liquid, and constantly shaken until the calcium-aluminum alloy is melted, and so on until the Ca-Al alloy is completely melted, and continue to stir to form a Pb-Sn-Co-Ag alloy strip for standby.

[0020] As an improvement of the present application, in step S1, the temperature of the positive lead melting pot is set to 475℃.

[0021] As an improvement of the present application, in step S1, the temperature of the negative lead melting pot is set to 480℃.

[0022] Compared with the prior art, the beneficial effects of the present application are: by using the Pb-Sn-Co-Ag alloy preparation method of the present application, adding appropriate proportions of Sn, Co, and Ag can effectively improve the corrosion resistance of the grid, improve the mechanical properties and electrochemical properties of the grid alloy, reduce water loss during battery charging, and improve the service life of the storage battery under high temperature conditions of 75℃. The Pb-Sn-Co-Ag alloy preparation method of the present application can improve the 75℃ life of the VRLA battery produced by the Pb-Sn-Co-Ag alloy by more than 90% compared with the conventional Pb-Ca alloy preparation method. BRIEF DESCRIPTION OF DRAWINGS

[0023] Fig. 1 is a flow chart of the Pb-Sn-Co-Ag alloy preparation method of the high-temperature-resistant life valve-regulated lead-acid battery according to the present application. DETAILED DESCRIPTION

[0024] The embodiments of the present disclosure will be described in detail below. The embodiments described below are exemplary and are only used to explain the present disclosure, and cannot be understood as a limitation of the present disclosure. If the specific technology or conditions are not specified in the embodiments, the technology or conditions described in the literature in the art or according to the product instructions are used.

[0025] The embodiment is a Pb-Sn-Co-Ag alloy preparation method of a high-temperature-resistant life valve-regulated lead-acid battery, which is divided into positive and negative Pb-Sn-Co-Ag alloys, and includes:

[0026] The positive rare earth silver alloy includes the following alloy components: Pb mass fraction 97.8%±0.5%, Sn mass fraction 1.70%±0.05%, Co mass fraction 0.25%±0.02%, Ag mass fraction 0.14%±0.02%, Ca mass fraction 0.080%±0.002%, and Al mass fraction 0.025%±0.002%.

[0027] The negative rare earth silver alloy comprises the following alloy components: Pb mass fraction 98.4%±0.5%, Sn mass fraction 1.20%±0.05%, Co mass fraction 0.18%±0.02%, Ag mass fraction 0.12%±0.02%, Ca mass fraction 0.090%±0.002%, and Al mass fraction 0.030%±0.002%.

[0028] When the Pb-Sn-Co-Ag alloy is prepared, the temperature of the positive rare earth silver alloy lead melting pot is set to 475 DEG C, and the temperature of the negative rare earth silver alloy lead melting pot is set to 480 DEG C.

[0029] By using the Pb-Sn-Co-Ag alloy preparation method in the embodiment of the application, the corrosion resistance of the grid can be effectively improved, the mechanical properties and electrochemical properties of the grid alloy can be improved, the water loss during the charging process of the battery can be reduced, and the service life of the storage battery under high temperature conditions of 75 DEG C can be improved. Compared with the conventional Pb-Ca alloy preparation method, the service life of the VRLA storage battery produced by using the Pb-Sn-Co-Ag alloy is increased by more than 90% under the condition of 75 DEG C.

[0030] In the embodiment of the application, a Pb-Sn-Co-Ag alloy preparation method for high-temperature-resistant and long-life valve-regulated lead-acid storage batteries is provided to achieve the above-mentioned purpose. The service life of the VRLA storage battery under the condition of 75 DEG C can be improved, and the service life of the battery can be increased by more than 90%.

[0031] In the embodiment of the application, the temperature during alloy preparation, the alloy components and the content are included.

[0032] As shown in FIG. 1, No. 1 electrolytic lead (Pb≥99.994%) is added to a lead melting pot according to the proportions in Table 1 and Table 2, and heated. The temperature of the positive lead melting pot is set to 475 DEG C, and the temperature of the negative lead melting pot is set to 480 DEG C. After the electrolytic lead is melted, stirring is performed. Tin ingots are added according to the proportions in Table 1 and Table 2, and heating and stirring are continued for 5 minutes. Cobalt ingots are added, and heating, dissolution and stirring are continued for 6 minutes. Silver ingots are added, and heating, dissolution and stirring are continued for 3 minutes. Ca-Al alloy (Ca mass fraction 70%, Al mass fraction 30%) is beaten into small pieces, wrapped with paper, and loaded into a bell jar with holes. The Ca-Al alloy is directly pressed under the molten lead liquid, and continuously shaken until the Ca-Al alloy is melted. The above-mentioned process is repeated until the Ca-Al alloy is completely melted. Stirring is continued for 10 minutes, and Pb-Sn-Co-Ag alloy strips are cast for standby use.

[0033] Table 1: Preparation method of the positive Pb-Sn-Co-Ag alloy in the embodiment

[0034] Table 2: Preparation method of the negative electrode Pb-Sn-Co-Ag alloy of the example

[0035] Table 3: Preparation method of the positive electrode Pb-Ca-Sn-Al alloy of the control example

[0036] Table 4: Preparation method of the negative electrode Pb-Ca-Sn-Al alloy of the control example

[0037] The content of the Pb-Sn-Co-Ag alloy components was detected by a German Spector direct-reading spectrometer, and the detection results are shown in Tables 5 and 6.

[0038] Table 5: Content of the positive electrode Pb-Sn-Co-Ag alloy components

[0039] Table 6: Content of the negative electrode Pb-Sn-Co-Ag alloy components

[0040] The 75℃ life test results of the batteries prepared in the above examples and control examples are shown in Table 7.

[0041] The Pb-Sn-Co-Ag alloy was produced into a grid and then into a plate to assemble a battery, which was assembled according to the EBU1-4-P (12V22Ah) battery production process, filled with acid, and then charged to obtain a valve-regulated lead-acid battery, and the 75℃ life test was performed.

[0042] The 75℃ life test was performed according to the SAE J2801-2018 standard;

[0043] 1. The battery was tested in a water bath at 75℃±3℃, and the water level should be kept greater than or equal to 75% of the total height of the battery tank, and the life test was carried out according to the following procedure:

[0044] a: 25A discharge for 18s;

[0045] b: 14.2V current-limiting 25A charging for 30min;

[0046] c: 3A discharge for 15min;

[0047] d: 14.2V current-limiting 25A charging for 30min;

[0048] e: 25A discharge for 18s;

[0049] f: 14.2V current-limiting 25A charging for 30min;

[0050] g: 3A discharge for 15min;

[0051] h: 14.2V, 25A, 30min;

[0052] i: 3A, 15min;

[0053] j: 14.2V, 25A, 29min 24s;

[0054] The battery is continuously cycled through steps a-j for a total of 6 cycles. Each cycle will take 3.25h;

[0055] k: After 6 cycles, discharge at 10A for 15min, then charge at 14.2V, 25A for 255min;

[0056] l: Repeat a-k, and add four more times;

[0057] m: Repeat a-j, and add four more times;

[0058] n: 10A, 15min;

[0059] o: 14.2V, 25A, 120min;

[0060] The outlined test is to be performed for one week. A total of 34 cycles are to be recorded for a successful test per week;

[0061] 2. The battery is left open circuit in a water bath at 75°C ± 3°C for 28 to 33 hours. The battery is discharged at 200A to 7.2V, or for the minimum of 10s, whichever comes first, at a temperature of 75°C ± 3°C;

[0062] 3. The life test is considered complete if one or more of the following occurs:

[0063] 3.1. The battery current acceptance is greater than 15A at the end of any step charge;

[0064] 3.2. The battery is unable to maintain a minimum voltage of 7.2V during any of the discharge steps;

[0065] 3.3. The battery terminal voltage drops to below 12.0V at the end of the rest period.

[0066] Table 7: Battery 75°C life comparison test results

[0067] According to the SAE J2801-2018 standard comparison test, the control example 75°C life is 6 cells, the example 75°C life is 14 cells, the example 75°C life is increased by more than 90% compared with the control example.

[0068] It should be noted that the above content only illustrates the technical idea of the present application, and cannot limit the protection scope of the present application. For ordinary skilled in the art, without departing from the principle of the present application, a number of improvements and refinements can be made, which fall within the protection scope of the claims of the present application.

Claims

1. A high temperature resistant, long life valve regulated lead acid battery lead tin cobalt silver alloy wherein, The Pb-Sn-Co-Ag alloy comprises the following alloy components: Pb mass fraction is 97% to 99%; Sn mass fraction is 1.20% to 1.80%; Co mass fraction is 0.18% to 0.3%; Ag mass fraction is 0.12% to 0.15%.

2. The high-temperature life resistant valve regulated lead acid battery lead tin cobalt silver alloy of claim 1, wherein, The Pb-Sn-Co-Ag alloy comprises a positive electrode Pb-Sn-Co-Ag alloy, The positive electrode Pb-Sn-Co-Ag alloy comprises the following alloy components, Pb mass fraction is 97.8%±0.5%, Sn mass fraction is 1.70%±0.05%, Co mass fraction is 0.25%±0.02%, and Ag mass fraction is 0.14%±0.02%.

3. The high-temperature life resistant valve regulated lead acid battery lead tin cobalt silver alloy of claim 2 wherein, The Pb-Sn-Co-Ag alloy comprises a negative electrode Pb-Sn-Co-Ag alloy, The negative electrode Pb-Sn-Co-Ag alloy comprises the following alloy components, Pb mass fraction is 98.4%±0.5%, Sn mass fraction is 1.20%±0.05%, Co mass fraction is 0.18%±0.02%, and Ag mass fraction is 0.12%±0.02%.

4. The high-temperature life resistant valve regulated lead acid battery lead tin cobalt silver alloy of claim 3, wherein, The Pb-Sn-Co-Ag alloy further comprises Ca, and the mass fraction of Ca is 0.025% to 0.085%.

5. The high-temperature life resistant valve regulated lead acid battery lead tin cobalt silver alloy of claim 4 wherein, The Pb-Sn-Co-Ag alloy further comprises Al, and the mass fraction of Al is 0.025%±0.002%.

6. The high-temperature life resistant valve regulated lead acid battery lead tin cobalt silver alloy of claim 4 wherein, The mass fraction of Ca in the positive electrode Pb-Sn-Co-Ag alloy is 0.080%±0.002%, and the mass fraction of Ca in the negative electrode Pb-Sn-Co-Ag alloy is 0.090%±0.002%.

7. The high-temperature life resistant valve regulated lead acid battery lead tin cobalt silver alloy of claim 4 wherein, The mass fraction of Al in the positive electrode Pb-Sn-Co-Ag alloy is 0.025%±0.002%, and the mass fraction of Al in the negative electrode Pb-Sn-Co-Ag alloy is 0.030%±0.002%.

8. A method of formulating a high-temperature life resistant valve regulated lead acid battery lead tin cobalt silver alloy according to any one of claims 1 to 7 wherein, The method comprises the following steps: Step S1, add electrolytic lead to the molten lead pot in proportion and heat; Step S2, after the electrolytic lead is melted, stir, add tin ingot in proportion and continue to heat and stir, add cobalt ingot and continue to heat, dissolve and stir, add silver ingot and continue to heat, dissolve and stir; Step S3, the Ca-Al alloy is broken into small pieces, wrapped with paper, and placed in a bell jar with holes, directly pressed under the molten lead liquid, and continuously shaken until the calcium-aluminum alloy is melted, and the process is repeated until the calcium-aluminum alloy is completely melted, and then continuously stirred to form a Pb-Sn-Co-Ag alloy strip for standby.

9. The method of formulating a high-temperature life resistant valve regulated lead acid battery lead tin cobalt silver alloy of claim 8 wherein, In step S1, the temperature of the positive electrode molten lead pot is set to 475°C.

10. The method of formulating a high-temperature life resistant valve regulated lead acid battery lead tin cobalt silver alloy of claim 8 wherein, In step S1, the temperature of the negative electrode molten lead pot is set to 480°C.

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