Author :Iflowpower – Portable Power Station Supplier
Today, today's highly developed today, various high-tech emerged in our lives, bring convenience for our lives, then do you understand the lithium-ion batteries that these high-tech may contain? Lithium-ion batteries important ingredients Contains housing, electrolyte, anode material, cathode material, adhesive, copper foil, and aluminum foil, etc. Among them, CO, Li, Ni mass fraction is 5% to 15%, 2% to 7%, 0.5% to 2%, as well as metal elements such as Al, Cu, Fe, and the value of important components, the anode The material and cathode materials account for about 33% and 10%, and the electrolyte and the diaphragm have accounted for 12% and 30%, respectively.
At present, the method of separating and recovery is important with solvent extraction, precipitation, electrolysis, ion exchange method, salting and etiology. 1, pretreatment 1.1, pre-charge: most of the remaining electricity in the used lithium ion battery must be completely discharged before discharge.
Otherwise, the residual energy will be concentrated in subsequent processing, which can lead to security hazards and other adverse effects. The discharge method of used lithium ion batteries can be divided into two types, namely physical discharge and chemical discharge. Among them, physical discharge is short-circuit discharge, which is usually frozen at low temperatures with refrigerants such as liquid nitrogen, and then mandatory by perforation.
1.2, crushing and separation: the process of crushing and separation is important, it combines electrode materials with other substances (organic materials, etc.) with other substances (organics, etc.
) through multi-stage crushing, screening and other separation techniques to achieve separation and enrichment of mechanical purposes. Use combustion method, wet method and other methods can recover valuable metals and compounds. Mechanical separation is one of the commonly used pretreatment methods, it is easy to realize the processing of large-scale industrial recovery and waste lithium-ion batteries.
1.3, heat treatment: The heat treatment process is very important to remove insoluble organic matter, toner, etc., toner, etc.
, toner materials, and current electrode materials and collectors. At present, most of the heat treatment methods used are high temperature conventional heat treatment, but there are problems such as separation depth and environmental pollution. In order to further improve the process, in recent years, more and more research on high-temperature vacuum pyrolysis.
1.4, dissolution method: The solubility method is based on similar compatibility principles, using a cathode material, an adhesive (important PVDF), aluminum foil and other impurities in an organic solvent in an organic solvent to achieve separation and enrichment. A strong polar organic solvent is typically selected to dissolve the PVDF on the electrode to distinguish the positive electrode material from the aluminum foil of the current collector.
2, the dissolution leaching dissolution leaching process of the electrode material is to dissolve and leach the electrode material obtained after pre-treatment, so that the metal element in the electrode material into the solution in an ionic form, then selectively separated and recovered important metal CO, Li et al. Methods of dissolving leaching Important include chemical leaching and biological leaching. 2.
1, chemical leaching: The traditional chemical leaching method is to achieve dissolution and leaching of the electrode material by acid immersion or alkaline, it is important to include a step leaching method and two-step leaching method. Single-step leaching method typically uses inorganic acid HCl, HNO3, H2SO4, etc., directly dissolved electrode materials as a leaching agent, but this method will appear harmful gases such as CL2, SO2, so exhaust gas treatment.
2.2, biological leaching method: With the development of technology, biometrial technology has better development trend and application prospects with its efficient, environmentally friendly and low cost advantages. Biological leaching is to use bacteria to oxidize the metal into a solution in ionic form.
In recent years, some researchers have studied methods of leaching from a waste lithium ion battery. 3. Separation and recovery of valuable metal elements in the leaching liquid 3.
1, solvent extraction method: solvent extraction method is currently more widely used in separating and recovering metal elements in waste lithium ion batteries. The principle is to use an organic solvent to form a stable complex with the target ion in the leaching solution, and then separate it using a suitable organic solvent to extract the target metal and the compound. 3.
2, precipitation method: The precipitation method is to dissolve the pretreated waste lithium ion battery and obtained CO and Li solution after acid dissolution, and add precipitant to settle the important target metal Co, Li, etc., thereby achieving metal separation. 3.
3, electrolysis: Electrolysis is to recover the precious metals in the lithium ion battery by chemical electrolytic electrode material leaching liquid to recover the precious metals in the lithium ion battery to simple substances or deposits. This method does not add other substances, it is difficult to introduce impurities, and product having higher purity can be obtained. However, total deposition will occur in the presence of multiple ions, which will reduce the purity of the product and consume more electrical energy.