Aqueous lead-lithium battery

Abstract

The application discloses a water-based lead-lithium battery, which comprises a positive electrode, a negative electrode and an electrolyte; the positive electrode contains a positive electrode active material; the negative electrode contains a negative electrode active material; the mass ratio of the positive electrode active material, the negative electrode active material and the electrolyte is 500-0.1:100-0.01:1000-0.1. The water-based lead-lithium battery has higher energy density and power density, and the cycle life is improved. The negative electrode active material is pretreated, so that nitrogen atoms are firmly combined with a lithium ion-embeddable and extractable base material (namely the negative electrode active material), the stability of lithium ions in the lithium ion embedding and extraction process is improved by using the high binding strength of the nitrogen atoms and the lithium ions, and the problem of dendrite is avoided.

Description

Technical Field

[0001] This invention relates to the field of storage batteries, and particularly to an aqueous lead-lithium battery. Background Technology

[0002] Aqueous electrolyte batteries are attracting increasing attention due to their advantages such as non-flammability, low cost, high power density, and environmental friendliness. However, the narrow electrochemical window for stability of water and low-capacity electrode materials severely limits their further development. To address this issue, a proposed approach is to combine the lead dioxide positive electrode of a lead-acid battery with a lithium-ion negative electrode material that allows for free insertion and extraction of lithium ions to form the positive and negative electrodes. A lead dioxide-lead-lithium ion battery is then prepared by adding a sulfuric acid solution containing soluble lithium salts inside the battery.

[0003] Lead-acid batteries, as a type of rechargeable battery, are widely used in hybrid electric vehicles (HEVs), SLI (starting, lighting, and ignition), and energy storage systems due to their mature technology, abundant raw materials, low cost, and good safety performance. However, when operating under high current density and undercharging conditions (i.e., high-rate partial state of charge (HRPSoC)), PbSO4 rapidly accumulates on the surface of the negative electrode, causing irreversible sulfation. Changing the composition of the negative electrode active material and electrolyte can fundamentally solve this problem and directly extend the lifespan of lead-acid batteries. By retaining the positive electrode and replacing the negative electrode with a modified electrode capable of embedding and extracting lithium ions, while replacing the electrolyte with a sulfuric acid solution containing lithium salts, the sulfation and hydrogen evolution problems of the negative electrode can be effectively solved. Furthermore, the energy density, power density, and cycle life of the battery can be significantly improved. This new type of battery is an ideal upgrade and replacement for lead-acid batteries. Summary of the Invention

[0004] To address the narrow stable electrochemical window of most water-based and low-capacity electrode materials (and to extend the duration of the stable electrochemical window under the same testing conditions), and to solve the problems of negative electrode sulfation and hydrogen evolution during lead-acid battery failure, the following solutions are proposed:

[0005] According to another aspect of this application, an aqueous lead-lithium battery is provided, the aqueous lead-lithium battery comprising a positive electrode, a negative electrode and an electrolyte;

[0006] The positive electrode contains a positive electrode active material;

[0007] The negative electrode contains a negative electrode active material;

[0008] The mass ratio of the positive electrode active material, the negative electrode active material and the electrolyte is 500-0.1:100-0.01:1000-0.1.

[0009] The mass ratio of the positive electrode active material, the negative electrode active material and the electrolyte is 120-20:40-1:200-50;

[0010] The positive electrode includes lead paste;

[0011] The positive electrode active material is lead from lead paste;

[0012] The negative electrode active material is selected from at least one of graphene, carbon nanotubes, multilayer graphite, lithium titanate, iron phosphate, cobalt phosphate, manganese dioxide, or molybdenum disulfide.

[0013] Optionally, the negative electrode active material is selected from multilayer graphite and / or iron phosphate.

[0014] The positive electrode is obtained through the following steps:

[0015] By weight, 500-800 parts of lead powder, 0.1-10 parts of carbon material, 6-10 parts of barium sulfate, and 0.1-0.5 parts of polypropylene fiber are stirred and premixed. While stirring, 50-100 parts of water are added and stirred continuously for 1-60 minutes to obtain lead paste.

[0016] The lead paste is scraped onto the surface of a metal grid, cured, and dried to obtain the positive electrode.

[0017] Optionally, the carbon material is selected from at least one of acetylene black, Super P, or carbon nanotubes;

[0018] Optionally, the polypropylene fiber has a length of 0.1 to 5 mm and a diameter of 100 nm to 5 μm.

[0019] The curing temperature is 30–50°C;

[0020] Optionally, the curing time is 10 to 30 hours;

[0021] Optionally, the drying temperature is 60–120°C;

[0022] Optionally, the drying time is 10 to 30 hours.

[0023] Optionally, the humidity of the drying process is 70-95%.

[0024] The negative electrode is obtained through the following steps:

[0025] By weight, raw materials containing 50-90 parts of the negative electrode active material, 5-40 parts of conductive carbon material, 10-5 parts of binder and 1000-1 part of water are mixed to obtain an active material paste.

[0026] The active material paste is scraped onto a metal grid and dried to obtain the negative electrode.

[0027] Optionally, the conductive carbon material is selected from at least one of acetylene black, SuperP, or commercially available KB carbon;

[0028] Optionally, the adhesive is selected from at least one of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), styrene-butadiene rubber (SBR), or carboxymethyl cellulose (CMC);

[0029] Optionally, the adhesive is selected from polytetrafluoroethylene;

[0030] Optionally, the mixing includes stirring;

[0031] Optionally, the stirring time is 1 to 60 minutes.

[0032] The drying temperature is 20–100°C;

[0033] Optionally, the drying temperature is 30–60°C;

[0034] Optionally, the drying time is 10 to 30 hours.

[0035] The negative electrode active material undergoes pretreatment;

[0036] Optionally, the preprocessing procedure includes the following steps:

[0037] The negative electrode active material is kept at a temperature in a nitrogen atmosphere;

[0038] Optionally, the insulation temperature is 200–800°C;

[0039] Optionally, the insulation temperature is 300–500°C;

[0040] Optionally, the heat preservation time is 1 to 24 hours;

[0041] Optionally, the heat preservation time is 4 to 8 hours.

[0042] The electrolyte includes lithium salt, sulfuric acid, and water;

[0043] Optionally, in the electrolyte, the mass ratio of lithium salt, sulfuric acid, and water is 10–0.1:10–0.1:100–1;

[0044] Optionally, the lithium salt is selected from at least one of lithium sulfate, lithium nitrate, lithium carbonate, lithium chloride, or lithium hexafluorophosphate;

[0045] Optionally, the sulfuric acid has a mass concentration of 95%.

[0046] The metal grid is a lead metal grid.

[0047] The metal lead plate grid has dimensions of 50–1000 mm in length, 20–80 mm in width, and 0.5–4 mm in thickness.

[0048] The lead paste or active substance paste fills the through holes on the metal lead plate grid.

[0049] The advantages of this application are:

[0050] 1. The aqueous lead-lithium battery described in this application has higher energy density and power density, and its cycle life is improved.

[0051] 2. The negative electrode active material used in this application undergoes pretreatment to ensure that nitrogen atoms are firmly bonded to the lithium ion intercalation and deintercalation substrate material (i.e., negative electrode active material). The high bonding strength between nitrogen atoms and lithium ions enhances the stability of lithium ions during the lithium ion intercalation and deintercalation process, thus avoiding dendrite formation. Detailed Implementation

[0052] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.

[0053] Unless otherwise specified, the raw materials and catalysts used in the embodiments of this application were all purchased commercially.

[0054] Example 1

[0055] The preparation method of the positive electrode of the lead-acid battery is as follows: (1) 600g of lead powder, 8.4g of barium sulfate, and 0.3g of polypropylene short fibers with a length of 5mm and a diameter of 1μm are premixed using a high-speed mixer. While stirring, 84g of deionized water is added to the premixed powder, and stirring is continued for 10min to obtain lead paste; (2) The lead paste is scraped onto a metal lead grid with a grid size of 70mm in length, 50mm in width, and 2mm in thickness. After curing and drying, the negative electrode of the lead-carbon battery is obtained. The curing temperature is 40℃, the humidity is 80%, and the curing time is 20 hours; the drying temperature is 80℃ and the time is 24 hours.

[0056] The modified lithium-ion electrode that can be inserted and extracted is prepared by placing 10g of multilayer graphite in a nitrogen environment and keeping it at 400℃ for 6 hours to obtain nitrogen-doped modified multilayer graphite negative electrode active material. The lead-acid battery negative electrode is prepared by: (1) according to the weight parts, 8.5g of the prepared nitrogen-doped modified multilayer graphite negative electrode active material, 1g of acetylene black and 0.5g of PTFE are stirred and premixed. While stirring, 50g of deionized water is added to the premixed powder and stirred continuously for 30min to obtain active material paste; (2) the active material paste prepared in step (1) is scraped onto the metal lead grid, the lead paste fills the through holes on the metal lead grid, and dried to obtain the lead-acid battery negative electrode; the drying temperature is 50℃ and the drying time is 12 hours.

[0057] The preparation method of the lead-acid battery electrolyte is as follows: 20g of lithium sulfate, 15g of 95% concentrated sulfuric acid solution and 65g of ultrapure water are thoroughly mixed to obtain 100g of electrolyte.

[0058] Preparation of lead-acid batteries: Three positive electrode plates and two negative electrode plates are arranged alternately and parallelly. A PE separator from a commercial lead-acid battery is placed between the positive and negative electrode plates. The two negative electrode plates are welded in parallel, and the three positive electrode plates are welded in parallel. The total mass of the positive electrode active material is 60.0g, which refers to the total mass of the lead paste contained in the three parallel-welded positive electrode plates. The total mass of the negative electrode active material is 12g. The positive and negative electrode grids use conventional lead grids with dimensions of 70mm long, 50mm wide, and 2mm thick. 80g of the prepared electrolyte is poured into the battery.

[0059] The battery underwent a room temperature life test under the following conditions: discharge at a constant current of 4.2A for 59 seconds, discharge at 18A for 1 second, and charge at a constant current and voltage of 6.3A (2.3V) for 60 seconds. This charge-discharge cycle was repeated 3600 times, followed by a 40-hour rest period. The cycle test was then resumed after 40 hours, ending when the battery voltage dropped below 1.2V. The initial voltage of the assembled battery at full charge at room temperature was 2.607V, and the battery completed 38099 cycles during the room temperature life test. Compared with the test results of a conventional lead-acid battery with the same lead content under the same test conditions (7206 cycles), the battery's room temperature cycle life is 5.3 times that of a traditional lead-acid battery.

[0060] Example 2

[0061] The process is the same as in Example 1, except that for the lead-acid battery: following the requirements of Example 1 without changing other conditions, the step of "placing 10g of multilayer graphite in a nitrogen environment and keeping it at 400°C for 6 hours to obtain nitrogen-doped modified multilayer graphite negative electrode active material" is replaced with "placing 10g of multilayer graphite in a nitrogen environment and keeping it at 800°C for 6 hours to obtain nitrogen-doped modified multilayer graphite negative electrode active material". The battery assembled under these conditions has an initial voltage of 2.601V under full charge at room temperature, and can run 28,892 cycles in the room temperature life test. Compared with the test results of a conventional lead-acid battery with the same lead content under the same test conditions (7,206 cycles), the room temperature cycle life of the prepared lead-acid battery can reach 4.0 times that of the conventional lead-acid battery.

[0062] Example 3

[0063] The process is the same as in Example 1, except that for the lead-acid battery: following the requirements of Example 1 without changing other conditions, the electrolyte preparation process is modified by replacing "thoroughly mixing 20g lithium sulfate, 15g 95% sulfuric acid solution, and 65g ultrapure water to obtain 100g electrolyte" with "thoroughly mixing 10g lithium sulfate, 15g 95% sulfuric acid solution, and 75g ultrapure water to obtain 100g electrolyte". The battery assembled under these conditions has an initial voltage of 2.723V under full charge at room temperature, and can run 32,825 cycles in the room temperature life test. Compared with the test results of a conventional lead-acid battery with the same lead content under the same test conditions (7,206 cycles), the room temperature cycle life of the prepared lead-acid battery can reach 4.6 times that of the conventional lead-acid battery.

[0064] Example 4

[0065] The process is the same as in Example 1, except that for the lead-acid battery: following the requirements of Example 1 without changing other conditions, the step of "pouring 80g of the prepared electrolyte into the battery" is replaced with "pouring 40g of the prepared electrolyte into the battery" during the electrolyte preparation process. The resulting battery, fully charged at room temperature, has an initial voltage of 2.715V, and can run 28,883 cycles in a room temperature life test. Compared with the test results of a conventional lead-acid battery with the same lead content under the same test conditions (7,206 cycles), the room temperature cycle life of the prepared lead-acid battery is four times that of a conventional lead-acid battery.

[0066] Example 5

[0067] The process is the same as in Example 1, except that for the lead-acid battery: according to the requirements of Example 1, without changing other conditions, in the process of preparing the electrolyte, the following is replaced with the following: "The preparation method of the negative electrode of the lead-acid battery is: (1) according to the weight parts, 8.5g of the prepared nitrogen-doped modified multilayer graphite negative electrode active material, 1g of acetylene black and 0.5g of PTFE are stirred and premixed, and 50g of deionized water is added to the premixed powder while stirring, and the active material paste is obtained by stirring continuously for 30 minutes". The battery assembled under the full charge state at room temperature has an initial voltage of 2.627V, and the assembled battery can run 21357 cycles in the room temperature life test. Compared with ordinary lead-acid batteries with the same lead content under the same test conditions (7206 cycles), the prepared lead-acid battery can achieve a cycle life of 3 times that of traditional lead-acid batteries at room temperature.

[0068] Comparative Example 1

[0069] The process is the same as in Example 1, except that for the lead-acid battery: following the requirements of Example 1 without changing other conditions, two copies of the prepared lead-acid battery positive electrode are made, one for use as the positive electrode and the other for use as the negative electrode. The battery prepared under these conditions is a lead-acid battery. The assembled battery has an initial voltage of 2.126V under full charge at room temperature, and the battery can withstand a life test of 7206 cycles under room temperature conditions.

[0070] Comparative Example 2

[0071] The process is the same as in Example 1, except that for the lead-acid battery: following the requirements of Example 1 without changing other conditions, the electrolyte in the prepared lead-acid battery is replaced with the same mass of sulfuric acid electrolyte with a density of 1.275 g / ml. The battery prepared under these conditions is a lead-acid battery. The initial voltage of the assembled battery under full charge at room temperature is 2.116V, and the battery can run for 7202 cycles under room temperature conditions.

[0072] Comparative Example 3

[0073] The process is the same as in Example 1, except that for the lead-acid battery: according to the requirements of Example 1, without changing other conditions, in the process of preparing the electrolyte, the following is replaced with "The preparation method of the negative electrode of the lead-acid battery is: (1) according to the weight parts, 8.5g of the prepared nitrogen-doped modified multilayer graphite negative electrode active material, 1g of acetylene black, and 0.5g of PTFE are stirred and premixed, and 50g of deionized water is added to the premixed powder while stirring, and the active material paste is obtained by stirring continuously for 30 minutes". PTFE was stirred and premixed, and 50g of deionized water was added to the premixed powder while stirring. Stirring was continued for 30 minutes to obtain active material paste. Due to the serious hydrogen evolution problem of the negative electrode of the prepared lead-acid battery, a large amount of electrode active material was detached during the battery test. The initial voltage of the assembled battery under full charge at room temperature was 2.614V. The assembled battery could run 3485 cycles in the room temperature life test.

[0074] Comparative Example 4

[0075] The process is the same as in Example 1, except that for the lead-acid battery: following the requirements of Example 1 without changing other conditions, in the process of preparing the electrolyte, "pour 80g of the prepared electrolyte into the battery" is replaced with "pour 0.5g of the prepared electrolyte into the battery". Due to the insufficient amount of electrolyte added, the electrode active material is severely lacking, resulting in the initial voltage of the assembled battery at room temperature under full charge being 2.568V. The assembled battery can run 142 cycles in the room temperature life test.

[0076] Comparative Example 5

[0077] The process is the same as in Example 1, except that for the lead-acid battery: following the requirements of Example 1 without changing other conditions, the step of "pouring 80g of the prepared electrolyte into the battery" is replaced with "repeatedly preparing the electrolyte until a total of 1100g of electrolyte is prepared, and then pouring 1000g of the prepared electrolyte into the battery". Due to the excessive amount of electrolyte added, the proportion of electrode active materials is severely unbalanced, leading to rapid sulfation of the positive electrode active material. As a result, the initial voltage of the assembled battery under full charge at room temperature is 2.003V, and the assembled battery can run 2652 cycles in the room temperature life test.

[0078] in conclusion

[0079] Based on the experimental results of the above embodiments and comparative examples, it can be seen that the aqueous lead-lithium battery described in this application solves the problem of narrow stable electrochemical window for most water and low-capacity electrode materials, and solves the problems of negative electrode sulfation and negative electrode hydrogen evolution during the failure of lead-acid batteries, ultimately achieving the effect of extending battery cycle life.

[0080] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. An aqueous lead-lithium battery, characterized in that, The aqueous lead-lithium battery includes a positive electrode, a negative electrode, and an electrolyte; The positive electrode contains a positive electrode active material; The positive electrode includes lead paste; The positive electrode active material is lead from lead paste; The negative electrode contains a negative electrode active material; The negative electrode active material is selected from at least one of graphene, carbon nanotubes, multilayer graphite, lithium titanate, iron phosphate, cobalt phosphate, manganese dioxide, or molybdenum disulfide. The negative electrode active material undergoes pretreatment; The preprocessing process includes the following steps: The negative electrode active material is kept at a temperature in a nitrogen atmosphere; The electrolyte includes lithium salt, sulfuric acid, and water; The mass ratio of the positive electrode active material, the negative electrode active material and the electrolyte is 500~0.1:100~0.01:1000~0.

1.

2. The aqueous lead-lithium battery according to claim 1, characterized in that, The mass ratio of the positive electrode active material, the negative electrode active material and the electrolyte is 120~20:40~1:200~50; The negative electrode active material is selected from multilayer graphite and / or iron phosphate.

3. The aqueous lead-lithium battery according to claim 1, characterized in that, The positive electrode is obtained through the following steps: By weight, 500-800 parts lead powder, 0.1-10 parts carbon material, 6-10 parts barium sulfate, and 0.1-0.5 parts polypropylene fiber are stirred and premixed. While stirring, 50-100 parts water are added and stirred continuously for 1-60 minutes to obtain lead paste. The lead paste is scraped onto the surface of a metal grid, cured, and dried to obtain the positive electrode; The carbon material is selected from at least one of acetylene black, Super P, or carbon nanotubes; The polypropylene fiber has a length of 0.1~5mm and a diameter of 100nm~5μm.

4. The aqueous lead-lithium battery according to claim 3, characterized in that, The curing temperature is 30~50℃; The curing time is 10~30 hours; The drying temperature is 60~120℃; The drying time is 10-30 hours.

5. The aqueous lead-lithium battery according to claim 1, characterized in that, The negative electrode is obtained through the following steps: By weight, raw materials containing 50-90 parts of the negative electrode active material, 5-40 parts of conductive carbon material, 10-5 parts of binder and 1000-1 parts of water are mixed to obtain an active material paste. The active material paste is scraped onto a metal grid and dried to obtain the negative electrode. The conductive carbon material is selected from at least one of acetylene black, SuperP, or commercial KB carbon. The adhesive is selected from at least one of polyvinylidene fluoride, polytetrafluoroethylene, styrene-butadiene rubber or carboxymethyl cellulose; The adhesive is selected from polytetrafluoroethylene; The mixing includes stirring; The stirring time is 1 to 60 minutes.

6. The aqueous lead-lithium battery according to claim 5, characterized in that, The drying temperature is 20~100℃; The drying temperature is 30~60℃; The drying time is 10-30 hours.

7. The aqueous lead-lithium battery according to claim 1, characterized in that, The insulation temperature is 200~800℃; The heat preservation time is 1~24h.

8. The aqueous lead-lithium battery according to claim 1, characterized in that, The insulation temperature is 300~500℃; The heat preservation time is 4-8 hours.

9. The aqueous lead-lithium battery according to claim 1, characterized in that, In the electrolyte, the mass ratio of lithium salt, sulfuric acid, and water is 10~0.1:10~0.1:100~1; The lithium salt is selected from at least one of lithium sulfate, lithium nitrate, lithium carbonate, lithium chloride, or lithium hexafluorophosphate. The sulfuric acid has a mass concentration of 95%.

10. The aqueous lead-lithium battery according to claim 3 or 5, characterized in that, The metal grid is a lead metal grid.

11. The aqueous lead-lithium battery according to claim 10, characterized in that, The metal lead plate grid has dimensions of 50-1000 mm in length, 20-80 mm in width, and 0.5-4 mm in thickness.