Sewage treatment and reuse method of lithium battery positive electrode material lithium manganese iron phosphate

Abstract

The invention relates to the technical field of lithium batteries, in particular to a sewage treatment and reuse method of a lithium battery positive electrode material lithium manganese iron phosphate. The method comprises the following steps: firstly, carrying out solid-liquid separation on sewage generated in the production process of lithium manganese iron phosphate to remove large-particle impurities and suspended solids so as to obtain primarily purified sewage; manganese, iron and lithium heavy metal ions in the sewage are removed, so that the heavy metal content in the effluent is lower than the national discharge standard; organic matters in the sewage are degraded by utilizing a biological treatment method or an advanced oxidation technology; the treated water can be directly reused for cleaning and dissolving in the production of lithium manganese iron phosphate, so that the cyclic utilization of water resources is realized; valuable metal elements such as manganese, iron and lithium can be recovered from the generated precipitates through subsequent treatment and can be reused as raw materials or by-products, so that the resource utilization rate is increased. Through specific physical and chemical treatment steps, harmful substances in the sewage are effectively removed, valuable metal ions are recycled, and resource utilization of the sewage is achieved.

Description

Technical Field

[0001] This invention relates to the field of lithium battery technology, and specifically to a wastewater treatment and reuse method for lithium manganese iron phosphate, a positive electrode material for lithium batteries. Background Technology

[0002] With the rapid development of new energy vehicles and energy storage technologies, lithium batteries, as their core components, have become a focus of industry attention in terms of performance optimization and cost control. Lithium manganese iron phosphate (LiMnFePO4), as a cathode material with high safety, long cycle life, and environmental friendliness, faces increasingly prominent wastewater treatment challenges during its production process. Traditional wastewater treatment methods often suffer from low treatment efficiency, high costs, and substandard recycled water quality, limiting the reduction of production costs and the fulfillment of environmental protection requirements. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a wastewater treatment and reuse method for lithium manganese iron phosphate, a cathode material for lithium batteries.

[0004] The technical solution adopted in this invention is as follows: A method for wastewater treatment and reuse of lithium manganese iron phosphate, a cathode material for lithium batteries, includes the following steps: The wastewater generated during the production of lithium manganese iron phosphate is first subjected to solid-liquid separation to remove large particulate impurities and suspended solids, resulting in preliminarily purified wastewater. Chemical precipitation or ion exchange methods are used to add appropriate amounts of precipitant or ion exchange resin to remove manganese, iron, and lithium heavy metal ions from wastewater, ensuring that the heavy metal content in the effluent is lower than the national discharge standards. Biological treatment methods or advanced oxidation technologies are used to degrade organic matter in wastewater, improve the biodegradability of wastewater or directly remove organic matter, and reduce chemical oxygen demand (COD) and biochemical oxygen demand (BOD). After the above treatment, the wastewater enters the deep purification stage, where reverse osmosis and nanofiltration membrane technologies are used to remove dissolved salts, microorganisms, and fine particulate matter, so that the water quality meets or approaches the production water standards; the treated water can be directly reused for cleaning and dissolving in the production of lithium manganese iron phosphate, realizing the recycling of water resources; During the removal of heavy metal ions, the precipitates produced can be further processed to recover valuable metal elements, such as manganese, iron, and lithium, which can then be reused as raw materials or by-products, thereby improving resource utilization.

[0005] Preferably, nanoscale lithium, manganese, iron, phosphorus sources and graphyne materials are prepared.

[0006] Preferably, the mixed solution containing graphylene is dried to remove the solvent and form a solid precursor. The drying process requires control of temperature and time to avoid damage to the material properties.

[0007] Preferably, after sintering, annealing is performed to further optimize the crystal structure and performance of the material, and improve the stability and conductivity of the material; the annealing temperature and time need to be adjusted according to the specific material characteristics. Preferably, the prepared lithium manganese iron phosphate composite cathode material is combined with conductive agents, binders and other auxiliary materials to prepare a lithium battery cathode sheet.

[0008] Preferably, the positive electrode is assembled with the negative electrode, separator, electrolyte, etc. to form a lithium battery.

[0009] Preferably, during the charging and discharging process of a lithium battery, the Li and electrons in the lithium manganese iron phosphate composite cathode material can migrate rapidly, achieving high energy density and long cycle life.

[0010] Preferably, the addition of graphdiene improves the conductivity of the material and enhances battery performance.

[0011] This invention provides a wastewater treatment and reuse method in the production process of lithium manganese iron phosphate composite cathode materials. This method effectively removes harmful substances from wastewater through specific physicochemical treatment steps, while recovering valuable metal ions, thereby realizing the resource utilization of wastewater.

[0012] The present invention has the following beneficial effects: This invention effectively reduces wastewater discharge during the production of lithium manganese iron phosphate, thereby reducing environmental pollution and aligning with the concept of green production. It enables the resource utilization of wastewater, reduces production water costs, and simultaneously recovers valuable metal elements, improving economic efficiency. The recovered water is of excellent quality and can be used in key steps of the production process, helping to improve the preparation quality and performance stability of lithium manganese iron phosphate composite cathode materials. This invention provides strong support for the environmental transformation and sustainable development of the lithium battery cathode material production industry. Detailed Implementation

[0013] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described content is only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0014] Example 1 The technical solution adopted by the present invention is provided in this embodiment as follows: A method for wastewater treatment and reuse of lithium manganese iron phosphate, a cathode material for lithium batteries, includes the following steps: The wastewater generated during the production of lithium manganese iron phosphate is first subjected to solid-liquid separation to remove large particulate impurities and suspended solids, resulting in preliminarily purified wastewater. Chemical precipitation or ion exchange methods are used to add appropriate amounts of precipitant or ion exchange resin to remove manganese, iron, and lithium heavy metal ions from wastewater, ensuring that the heavy metal content in the effluent is lower than the national discharge standards. Biological treatment methods or advanced oxidation technologies are used to degrade organic matter in wastewater, improve the biodegradability of wastewater or directly remove organic matter, and reduce chemical oxygen demand (COD) and biochemical oxygen demand (BOD). After the above treatment, the wastewater enters the deep purification stage, where reverse osmosis and nanofiltration membrane technologies are used to remove dissolved salts, microorganisms, and fine particulate matter, so that the water quality meets or approaches the production water standards; the treated water can be directly reused for cleaning and dissolving in the production of lithium manganese iron phosphate, realizing the recycling of water resources; During the removal of heavy metal ions, the precipitates produced can be further processed to recover valuable metal elements, such as manganese, iron, and lithium, which can then be reused as raw materials or by-products, thereby improving resource utilization.

[0015] Preferably, nanoscale lithium, manganese, iron, phosphorus sources and graphyne materials are prepared.

[0016] Preferably, the mixed solution containing graphylene is dried to remove the solvent and form a solid precursor. The drying process requires control of temperature and time to avoid damage to the material properties.

[0017] Preferably, after sintering, annealing is performed to further optimize the crystal structure and performance of the material, and improve the stability and conductivity of the material; the annealing temperature and time need to be adjusted according to the specific material characteristics. Preferably, the prepared lithium manganese iron phosphate composite cathode material is combined with conductive agents, binders and other auxiliary materials to prepare a lithium battery cathode sheet.

[0018] Preferably, the positive electrode is assembled with the negative electrode, separator, electrolyte, etc. to form a lithium battery.

[0019] Preferably, during the charging and discharging process of a lithium battery, the Li and electrons in the lithium manganese iron phosphate composite cathode material can migrate rapidly, achieving high energy density and long cycle life.

[0020] Preferably, the addition of graphdiene improves the conductivity of the material and enhances battery performance.

[0021] This invention provides a wastewater treatment and reuse method in the production process of lithium manganese iron phosphate composite cathode materials. This method effectively removes harmful substances from wastewater through specific physicochemical treatment steps, while recovering valuable metal ions, thereby realizing the resource utilization of wastewater.

Claims

1. A method for treating wastewater of lithium battery cathode material lithium iron manganese phosphate, characterized in that, Comprising the following steps: The wastewater produced in the production process of lithium manganese iron phosphate is first subjected to solid-liquid separation to remove large particle impurities and suspended solids, obtaining preliminarily purified wastewater; Chemical precipitation method or ion exchange method is adopted to add an appropriate amount of precipitant to the wastewater or use ion exchange resin to remove manganese, iron and lithium heavy metal ions in the wastewater, so as to ensure that the heavy metal content in the effluent is lower than the national discharge standard; Biological treatment method or advanced oxidation technology is used to degrade organic matter in the wastewater, improve the biodegradability of the wastewater or directly remove organic matter, reduce chemical oxygen demand and biochemical oxygen demand; After the above treatment, the wastewater enters the deep purification stage, and reverse osmosis and nanofiltration membrane technology are used to remove dissolved salts, microorganisms and small particles, so that the water quality reaches or approaches the production water standard; the treated water is directly used for cleaning and dissolution in the production of lithium manganese iron phosphate, realizing water resource recycling; In the heavy metal ion removal process, the precipitate produced is recycled through subsequent treatment to recover valuable metal elements, manganese, iron and lithium, which are reused as raw materials or byproducts, improving resource utilization.

2. The method for wastewater treatment and reuse of lithium battery cathode material lithium manganese iron phosphate according to claim 1, characterized in that, Prepare nanoscale lithium source, manganese source, iron source, phosphorus source and graphdiyne material.

3. The method for wastewater treatment and reuse of lithium battery cathode material lithium manganese iron phosphate according to claim 1, characterized in that, Dry the mixed solution containing graphdiyne to remove the solvent and form a solid precursor; the drying process needs to control the temperature and time to avoid damage to the material properties.

4. The method for wastewater treatment and reuse of lithium battery cathode material lithium iron manganese phosphate according to claim 1, characterized in that, After sintering, annealing treatment is performed to optimize the crystal structure and properties of the material and improve the stability and conductivity of the material; the annealing temperature and time need to be adjusted according to the specific material properties.

5. The method for wastewater treatment and reuse of lithium battery cathode material lithium iron manganese phosphate according to claim 1, characterized in that, Use the prepared lithium manganese iron phosphate composite cathode material to prepare lithium battery cathode sheets combined with conductive agents and adhesive auxiliary materials.

6. The method for wastewater treatment and reuse of lithium battery cathode material lithium iron manganese phosphate according to claim 1, characterized in that, Assemble the lithium battery by assembling the cathode sheet with the anode sheet, the separator and the electrolyte.

7. The method for wastewater treatment and reuse of lithium battery cathode material lithium iron manganese phosphate according to claim 1, characterized in that, In the charging and discharging process of the lithium battery, Li and electrons in the lithium manganese iron phosphate composite cathode material can quickly migrate, realizing high energy density and long cycle life.

8. The method for wastewater treatment and reuse of lithium battery cathode material lithium iron manganese phosphate according to claim 1, characterized in that, The addition of graphdiyne improves the conductivity of the material and enhances the battery performance.