What are the recycling methods for lithium iron phosphate batteries?

The service life of lithium iron phosphate battery is about 2-3 years, and the used lithium iron phosphate battery contains 27% lithium cobalt oxide. Because of its special physical and chemical properties, cobalt is widely used in industries, medical and other fields, and is an important international strategic material; copper and aluminum materials account for 10% of lithium iron phosphate batteries. The impact of recycling on resources and economy is obvious. There are three types of recycling methods for waste lithium iron phosphate batteries: physical method, chemical method and biological method. Lithium iron phosphate battery physical method Because the components in the lithium iron phosphate battery are different in physical properties, they are separated by different methods such as high temperature incineration, solvent dissolution, cracking and screening, and chemical changes will occur during the separation. 1. The fire method is used to burn the binding material of waste lithium iron phosphate batteries at a high temperature. The binding material will be analyzed under higher temperature conditions to achieve the purpose of removal, so that the components between the waste batteries are separated, and at high temperature During the incineration process, the metals and their compounds contained in the battery will also undergo chemical reactions and various compounds will appear, and these high-temperature smoke (dust) will be condensed and collected. Sony’s research is to burn used batteries at high temperature to separate iron and copper, then heat the remaining part to soak in acid, filter and extract cobalt with organic solvent. 2. The mechanical sorting method removes the used lithium iron phosphate batteries, and sorts them according to the differences in the density, specific heat, and magnetic properties of the components of the used lithium iron phosphate batteries. Combine mechanical separation and wet method to solve the waste lithium iron phosphate battery. First, remove the waste lithium iron phosphate battery to separate the plastic shell and metal. According to the magnetism of the metal, the iron is sieved out, and the remaining part is acidified. , After filtration, the leachate is recovered by wet method. 3. The organic solvent method lithium iron phosphate battery is based on the principle of close compatibility. The battery binder polyvinylidene fluoride is dissolved in the organic solvent to achieve the purpose of separating lithium cobaltate from the aluminum box, and it is easy to directly recover the aluminum box, and in the later stage Interference is eliminated when recovering cobalt. The proposal is convenient and the recovery rate is high. Chemical methods usually use strong acid, strong alkali and other strong oxidizing reagents to extract metal ions such as cobalt, lithium, and aluminum from waste lithium iron phosphate batteries, and use operations such as precipitation, extraction, and salting to separate metal elements such as cobalt and lithium. Purification. 1. The precipitation method is based on the different metal valence states of different metal compounds in the waste lithium iron phosphate battery, and the high valence cobalt compound is obtained from the waste lithium iron phosphate battery through precipitation. The leaching solution of the waste battery after acid solution contains cobalt and lithium in the form of ions, and the impurity-removing leaching solution can be purified to obtain cobalt and lithium precipitates. This method has a high metal recovery rate. 2. The salting-out method adds salts that do not undergo chemical reaction to the original solution until the original solution is supersaturated and some solutes can be precipitated, and valuable metals can be recycled. 3. The mechanochemical method is used to grind the electrode material and certain substances. During this process, a large amount of heat energy will be generated, and the high temperature in turn will cause a series of chemical reactions between the two, and finally cause the lithium cobalt oxide on the positive electrode of the battery to be converted into other forms The common grinding material is PVC (polyvinyl chloride) biological method, which uses microorganisms to convert the components in the waste lithium iron phosphate battery into soluble compounds, and dissolves the target metal to form a solution through operation to make useful components Get effective separation. The recycling process of used lithium iron phosphate batteries is mostly a combination of several methods, but each method has its own advantages and disadvantages. The wet process is more complete and the recovery rate is high, but the process consumes more strong oxidizing solvents and causes secondary pollution; the dry process has high energy consumption during the high-temperature incineration of waste lithium iron phosphate batteries, and it is harmful to the air. The quality is affected. Disclaimer: Some pictures and content of the articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous post: What to pay attention to when charging and discharging polymer lithium batteries