Preparation method of ferromanganese carbonate for lithium battery
The co-precipitation method is used to synthesize ferromanganese carbonate, which solves the problems of uneven morphology, unstable iron-manganese ratio, and uneven distribution of metal ions in the existing technology. High-purity ferromanganese carbonate material suitable for industrial production is prepared, achieving high yield and low impurity ion content.
Patent Information
- Application Number
- CN202510866384.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-25
- Publication Date
- 2025-09-12
AI Technical Summary
The existing technology lacks a mature process route for synthesizing ferromanganese carbonate, resulting in uneven morphology, unstable iron-manganese ratio, and uneven distribution of metal ions, making it difficult to meet the needs of industrial production.
Ferromanganese carbonate was synthesized by co-precipitation method. By controlling the iron-manganese molar ratio to 4:6, using antioxidants and carbonate ion solution, carrying out precipitation reaction under N2 atmosphere, controlling pH value and droplet acceleration rate, combined with hot water washing and drying treatment, a material with uniform morphology, controllable iron-manganese ratio and uniform metal ion distribution was prepared.
The ferromanganese carbonate material has uniform morphology, stable iron-manganese ratio, and uniform distribution of metal ions. The yield is as high as 98.2%-99.4%, which meets the requirements of industrial production and reduces the content of impurity ions, making it suitable for large-scale production.
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Figure CN120622545A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of battery materials, in particular to ferromanganese carbonate materials and a preparation method thereof. Background Art
[0002] With a growing understanding of lithium-ion battery materials and the continued high international crude oil prices, many researchers have focused their attention on lithium-ion power batteries, particularly those used in automotive applications. Lithium manganese oxide (LiMnO) or lithium iron phosphate (LiFePO) as cathode materials offer improved safety performance in lithium-ion batteries. While LiMnO is more mature in terms of technology, lithium iron phosphate (LFP) offers superior safety and cycling performance. However, LFP's operating voltage only reaches 3.4V, which is insufficient to meet the high energy density requirements of current power batteries. Lithium manganese iron phosphate (LFMP) is a novel cathode material that incorporates manganese into LFP. The manganese doping increases the charge and discharge voltage to 4.1V, significantly improving the cathode material's energy density. LFMP boasts a theoretical energy density 20% higher than LFP. Furthermore, the abundance and low cost of manganese contribute to LFMP's low cost. Combining the advantages of LFP, LFMP offers a safe, low-cost, and high-energy-density cathode material for lithium-ion batteries.
[0003] The significant development potential of LFMP has attracted considerable attention and research, and the preparation of its precursors, such as ferromanganese carbonate and ferromanganese oxide, has also attracted widespread attention. Available methods for synthesizing ferromanganese carbonate include coprecipitation, hydrothermal, sol-gel, and solid-phase reaction. The hydrothermal method requires high equipment and is costly, while the sol-gel method is complex and yields low yields. The solid-phase reaction method can produce uneven element distribution and requires subsequent processing. The coprecipitation method is simple and suitable for industrial production, primarily as a precursor for lithium-ion battery cathode materials (such as lithium iron manganese phosphate). However, the preparation of ferromanganese carbonate is currently underresearched, and there is no established process route.
[0004] The invention discloses a mature process route for synthesizing ferromanganese carbonate by a co-precipitation method, which can obtain a product with uniform morphology, stable iron-manganese ratio and uniform metal ion distribution. Summary of the Invention
[0005] The purpose of the present invention is to provide a method for preparing Mn6Fe4CO3 material for batteries, forming a mature, simple process synthesis route suitable for industrial production, and preparing a material with uniform morphology, controllable iron-manganese ratio, and uniform metal ion distribution.
[0006] To achieve the above object, the present invention provides a method for synthesizing Mn6Fe4CO3, which is specifically as follows:
[0007] A method for preparing ferromanganese carbonate for lithium batteries comprises the following steps:
[0008] (1) Manganese salt and iron salt were weighed and dissolved in a molar ratio of 4:6 to prepare a mixed solution A, and an antioxidant with a concentration of 0.1% by mass was added to the solution A;
[0009] (2) Prepare a solution containing carbonate ions as B;
[0010] (3) taking a 0.5-0.7% carbonate ion-containing solution as a base solution, adding solution A and solution B at a molar ratio of 1:1.2 dropwise and mixing, and performing a precipitation reaction under a N2 atmosphere;
[0011] (4) Control the solution pH to 6.0-8.0, control the dropwise acceleration rate, the reaction time to 1-5 h, and the reaction temperature to 25-40°C;
[0012] (5) Filter, wash 2-3 times with deionized water at 35-95°C, and dry at 70-90°C for 10-14 hours to obtain Mn6Fe4CO3 powder.
[0013] Wherein, the manganese salt described in step (1) is a mixture of one or more of manganese chloride, manganese carbonate and manganese sulfate.
[0014] A preferred manganese salt is manganese sulfate.
[0015] The iron salt described in step (1) is a mixture of one or more of ferrous sulfate, ferrous nitrate and ferrous chloride.
[0016] The preferred iron salt is ferrous sulfate.
[0017] The antioxidant in step (1) is selected from ascorbic acid, citric acid, vitamin E and quercetin.
[0018] Ascorbic acid is preferred.
[0019] The carbonate ion-containing solution in step (2) comes from ammonium bicarbonate, sodium carbonate and potassium carbonate.
[0020] Ammonium bicarbonate is preferred.
[0021] The base liquid in step (3) is a 0.6% carbonate ion solution.
[0022] In order to control the reaction rate, avoid local oversaturation and make the particle size uniform, a 0.6% carbonate ion-containing solution is taken as the base solution, and the two solutions AB are mixed by dropping A into B, B into A, or A and B are dropped at the same time, preferably A and B are dropped at the same time.
[0023] In step (4), the small-scale laboratory preparation is carried out, the droplet rate is controlled at 5-10 mL / min, the reaction time is 1-5 h, the reaction temperature is 25-40° C., and the solution pH is controlled at 6.0-8.0.
[0024] The hot water washing temperature in step (5) of the present invention is 60° C., and the drying temperature is 80° C. for 10 hours.
[0025] The present invention adopts a co-precipitation method to synthesize ferromanganese carbonate. The ratio of manganese to ferromanganese, which is widely used in industry, is about 4:6. The yield range of the method is 98.2%-99.4%. The content of sulfate and nitrate in the final product is as low as 90 ppm, which is far lower than the content specified in the standard and does not affect the product quality.
[0026] Compared with the prior art, the present invention has the following beneficial effects:
[0027] 1. The present invention utilizes the similar precipitation coefficients of divalent manganese and divalent iron, and performs co-precipitation in a carbonate solution, which can uniformly mix the two elements of manganese and iron at the atomic level. The material with a controllable manganese-iron ratio can be prepared according to demand. The iron-manganese ratio is stable at 4:6, the morphology and particle size are controllable, and the content of sulfate and nitrate ions is low.
[0028] 2. The preparation process of the present invention has mild conditions, simple operation, abundant and easily available raw materials, high yield, does not generate a large amount of waste that pollutes the environment, has simple equipment, and is very suitable for large-scale industrial production. BRIEF DESCRIPTION OF THE DRAWINGS
[0029] Figure 1 This is the SEM image of Mn6Fe4CO3 prepared in Example 1 of the present invention.
[0030] Figure 2 This is the SEM image of Mn6Fe4CO3 prepared in Example 2 of the present invention.
[0031] Figure 3 This is the SEM image of Mn6Fe4CO3 prepared in Example 3 of the present invention.
[0032] Figure 4 This is the SEM image of Mn6Fe4CO3 prepared in Example 4 of the present invention.
[0033] Figure 5 This is the SEM image of Mn6Fe4CO3 prepared in Example 5 of the present invention. DETAILED DESCRIPTION
[0034] 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 embodiments described 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 making creative efforts are within the scope of protection of the present invention.
[0035] Example 1
[0036] A method for preparing ferromanganese carbonate for lithium batteries comprises the following steps:
[0037] (1) Mix 500 mL of 1 mol / L ferrous sulfate solution and 750 mL of 1 mol / L manganese sulfate solution, and add 1.25 g (equivalent to 0.1% mass concentration) of ascorbic acid, which is recorded as solution A.
[0038] (2) Prepare 1.5 L of 1 mol / L ammonium bicarbonate solution, referred to as solution B.
[0039] (3) Take 0.6% ammonium bicarbonate solution as the base liquid, and add the two solutions of step 1 and 2 dropwise at the same speed and flow in parallel for reaction. The molar ratio of solution A to solution B is 1:1.2, and the reaction is carried out in a N2 atmosphere.
[0040] (4) The reaction temperature of step 3 was controlled to be 35°C, the reaction liquid droplet acceleration was 10 mL / min, the reaction was carried out for 3 h, and the pH was adjusted to 6.5-7.0 with aqueous ammonia.
[0041] (5) After the reaction is completed, the product is filtered, washed with deionized water at 60°C for 2-3 times, and dried at 80°C for 12 hours to obtain a Mn6Fe4CO3 powder product.
[0042] SEM Figure 1 , the temperature and the dropping speed are increased, under which conditions, uniform and smooth spherical agglomerates are obtained; SO4 2- The content of sulfate in the product increased with the increase of the dropping speed; the molar ratio of iron to manganese was 4:6.
[0043] Example 2
[0044] A method for preparing ferromanganese carbonate for lithium batteries comprises the following steps:
[0045] (1) Mix 500 mL of 1 mol / L ferrous sulfate solution and 750 mL of 1 mol / L manganese sulfate solution, and add 1.25 g of vitamin E. This is referred to as solution A.
[0046] (2) Prepare 1.5 L of 1 mol / L ammonium bicarbonate solution, referred to as solution B.
[0047] (3) Take 0.6% ammonium bicarbonate solution as the base liquid, and add the two solutions of step 1 and 2 dropwise at the same speed and flow in parallel for reaction. The molar ratio of solution A to solution B is 1:1.2, and the reaction is carried out in a N2 atmosphere.
[0048] (4) The reaction temperature of step 3 was controlled to be 35°C, the reaction liquid droplet acceleration was 10 mL / min, the reaction was carried out for 3 h, and the pH was adjusted to 7.5-8.0 with aqueous ammonia.
[0049] (5) After the reaction is completed, the product is filtered, washed with deionized water at 60°C for 2-3 times, and dried at 80°C for 12 hours to obtain a Mn6Fe4CO3 powder product.
[0050] SEM Figure 2 , a high pH value will affect the product morphology and produce agglomerates with rough surfaces; SO4 2- It is relatively high, at 3600ppm. The high pH of the reaction system will result in a relatively high content of sulfate in the product; the iron-manganese molar ratio is 4:6.
[0051] Example 3
[0052] A method for preparing ferromanganese carbonate for lithium batteries comprises the following steps:
[0053] (1) Mix 500 mL of 1 mol / L ferrous sulfate solution and 750 mL of 1 mol / L manganese sulfate solution, and add 1.25 g of citric acid. This is referred to as solution A.
[0054] (2) Prepare 1.5 L of 1 mol / L ammonium bicarbonate solution, referred to as solution B.
[0055] (3) Take 0.6% ammonium bicarbonate solution as the base liquid, and add the two solutions of step 1 and 2 dropwise at the same speed and flow in parallel for reaction. The molar ratio of solution A to solution B is 1:1.2, and the reaction is carried out in a N2 atmosphere.
[0056] (4) The reaction temperature of step 3 was controlled to be 35°C, the reaction liquid droplet acceleration was 5 mL / min, the reaction was carried out for 5 h, and the pH was adjusted to 6.5-7 with ammonia water.
[0057] (5) After the reaction is completed, the product is filtered, washed with deionized water at 60°C for 2-3 times, and dried at 80°C for 12 hours to obtain a Mn6Fe4CO3 powder product.
[0058] SEM Figure 3 , obtaining slightly loose uniform agglomerates; SO4 2- The reaction temperature is 900ppm, and the increase in reaction temperature affects the sulfate washing effect of the product and increases the sulfate ion content in the product; the iron-manganese molar ratio is 4:6.
[0059] Example 4
[0060] A method for preparing ferromanganese carbonate for lithium batteries comprises the following steps:
[0061] (1) Mix 500 mL of 1 mol / L ferrous sulfate solution and 750 mL of 1 mol / L manganese sulfate solution, and add 1.25 g of ascorbic acid. This is referred to as solution A.
[0062] (2) Prepare 1.5 L of 1 mol / L ammonium bicarbonate solution, referred to as solution B.
[0063] (3) Take 0.6% ammonium bicarbonate solution as the base liquid, and add the two solutions of step 1 and 2 dropwise at the same speed and flow in parallel for reaction. The molar ratio of solution A to solution B is 1:1.2, and the reaction is carried out in a N2 atmosphere.
[0064] (4) The reaction temperature of step (3) was controlled to be 25° C., the reaction liquid droplet acceleration was 5 mL / min, the reaction was carried out for 5 h, and the pH was adjusted to 6.5-7.0 with aqueous ammonia.
[0065] (5) After the reaction is completed, the product is filtered, washed with deionized water at 60°C for 2-3 times, and dried at 80°C for 12 hours to obtain a Mn6Fe4CO3 powder product.
[0066] SEM Figure 4 , obtaining slightly loose uniform agglomerates; improving the sulfate washing effect by affecting the morphology, SO4 2- It can be as low as 90ppm. Reducing the dripping speed can greatly reduce the sulfate ion content in the product and improve the washing efficiency; the iron-manganese molar ratio is 4:6.
[0067] Example 5
[0068] A method for preparing ferromanganese carbonate for lithium batteries comprises the following steps:
[0069] (1) Mix 500 mL of 1 mol / L ferrous sulfate solution and 750 mL of 1 mol / L manganese sulfate solution, and add 1.25 g of ascorbic acid. This is referred to as solution A.
[0070] (2) Prepare 1.5 L of 1 mol / L ammonium bicarbonate solution, referred to as solution B.
[0071] (3) Take 0.6% ammonium bicarbonate solution as the base liquid, and add the two solutions of step 1 and 2 dropwise at the same speed and flow in parallel for reaction. The molar ratio of solution A to solution B is 1:1.2, and the reaction is carried out in a N2 atmosphere.
[0072] (4) The reaction temperature of step 3 was controlled to be 25°C, the reaction liquid droplet acceleration was 5 mL / min, the reaction was carried out for 5 h, and the pH was adjusted to 6.5-7.0 with aqueous ammonia.
[0073] (5) After the reaction is completed, the product is filtered, washed with deionized water at 95°C for 2-3 times, and dried at 80°C for 12 hours to obtain a Mn6Fe4CO3 powder product.
[0074] SEM Figure 5 , the iron-manganese molar ratio is 4.2:5.8. The washing temperature has an impact on the iron-manganese molar ratio and will reduce the Mn content.
[0075] Example 6
[0076] A method for preparing ferromanganese carbonate for lithium batteries comprises the following steps:
[0077] (1) Mix 500 mL of 1 mol / L ferrous nitrate solution and 750 mL of 1 mol / L manganese carbonate solution, and add 1.25 g of citric acid. This is referred to as solution A.
[0078] (2) Prepare 1.5 L of 1 mol / L sodium carbonate solution, referred to as solution B.
[0079] (3) Take 0.5% sodium carbonate solution as the base liquid, and add the two solutions of step 1 and 2 dropwise at the same speed and flow in parallel for reaction. The molar ratio of solution A to solution B is 1:1.2, and the reaction is carried out in a N2 atmosphere.
[0080] (4) The reaction temperature of step 3 was controlled to be 40°C, the reaction liquid droplet acceleration was 7 mL / min, the reaction was carried out for 4 h, and the pH was adjusted to 6.0-6.5 with aqueous ammonia.
[0081] (5) After the reaction is completed, the product is filtered, washed with deionized water at 35°C for 2-3 times, and dried at 90°C for 10 h to obtain a Mn6Fe4CO3 powder product.
[0082] Example 7
[0083] A method for preparing ferromanganese carbonate for lithium batteries comprises the following steps:
[0084] (1) Mix 500 mL of 1 mol / L ferrous chloride solution and 750 mL of 1 mol / L manganese chloride solution, and add 1.25 g of vitamin E. This is referred to as solution A.
[0085] (2) Prepare 1.5 L of 1 mol / L potassium carbonate solution, referred to as solution B.
[0086] (3) Take 0.7% potassium carbonate solution as the base solution, and add the two solutions of step 1 and 2 dropwise at the same speed and flow in parallel for reaction. The molar ratio of solution A to solution B is 1:1.2, and the reaction is carried out in a N2 atmosphere.
[0087] (4) The reaction temperature of step 3 was controlled to be 40°C, the reaction liquid droplet acceleration was 10 mL / min, the reaction was carried out for 1 h, and the pH was adjusted to 7.5-8.0 with ammonia water.
[0088] (5) After the reaction is completed, the product is filtered, washed with deionized water at 55°C for 2-3 times, and dried at 70°C for 14 hours to obtain a Mn6Fe4CO3 powder product.
[0089] Example 8
[0090] A method for preparing ferromanganese carbonate for lithium batteries comprises the following steps:
[0091] (1) Mix 500 mL of 1 mol / L ferrous chloride solution, 250 mL of 1 mol / L manganese carbonate solution, and 500 mL of 1 mol / L manganese chloride solution, and add 1.25 g of quercetin. This is referred to as solution A.
[0092] (2) Prepare 1.5 L of 1 mol / L potassium carbonate solution, referred to as solution B.
[0093] (3) Take 0.6% potassium carbonate solution as the base solution, and add the two solutions of step 1 and 2 dropwise at the same speed and flow in parallel to react. The molar ratio of solution A to solution B is 1:1.2, and the reaction is carried out in a N2 atmosphere.
[0094] (4) The reaction temperature of step 3 was controlled to be 25°C, the reaction liquid droplet acceleration was 5 mL / min, the reaction was carried out for 5 h, and the pH was adjusted to 6.5-7.0 with aqueous ammonia.
[0095] (5) After the reaction is completed, the product is filtered, washed with deionized water at 60°C for 2-3 times, and dried at 80°C for 12 hours to obtain a Mn6Fe4CO3 powder product.
Claims
1. A method for preparing ferromanganese carbonate for lithium batteries, characterized in that: The following steps are involved: (1) Manganese salt and iron salt were weighed and dissolved in a molar ratio of 4:6 to prepare a mixed solution A, and an antioxidant with a concentration of 0.1% by mass was added to the solution A; (2) Prepare a solution containing carbonate ions as B; (3) taking a 0.5-0.7% carbonate ion-containing solution as a base solution, adding solution A and solution B at a molar ratio of 1:1.2 dropwise and mixing, and performing a precipitation reaction under a N2 atmosphere; (4) Control the solution pH to 6.0-8.0, control the dropwise acceleration rate, the reaction time to 1-5 h, and the reaction temperature to 25-40°C; (5) Filter, wash 2-3 times with deionized water at 35-95°C, and dry at 70-90°C for 10-14 hours to obtain Mn6Fe4CO3 powder.
2. The method for preparing ferromanganese carbonate for lithium batteries according to claim 1, wherein: The manganese salt described in step (1) is a mixture of one or more of manganese chloride, manganese carbonate and manganese sulfate.
3. The method for preparing ferromanganese carbonate for lithium batteries according to claim 1, wherein: The iron salt described in step (1) is a mixture of one or more of ferrous sulfate, ferrous nitrate and ferrous chloride.
4. The method for preparing ferromanganese carbonate for lithium batteries according to claim 1, wherein: The antioxidant in step (1) is selected from ascorbic acid, citric acid, vitamin E and quercetin.
5. The method for preparing ferromanganese carbonate for lithium batteries according to claim 1, wherein: The carbonate ion-containing solution in step (2) comes from ammonium bicarbonate, sodium carbonate and potassium carbonate.
6. The method for preparing ferromanganese carbonate for lithium batteries according to claim 1, wherein: The base liquid in step (3) is a 0.6% carbonate ion solution.
7. The method for preparing ferromanganese carbonate for lithium batteries according to claim 1, characterized in that: The hot water washing temperature in step (5) is 60° C., and the drying temperature is 80° C. for 10 h.