What is the resource technology of waste lithium-ion battery?

Resourcing technology for used lithium-ion batteries: Wet recovery technology.

The resource technology of used lithium-ion batteries is to separate the valuable components of used lithium-ion batteries according to their respective physical and chemical properties. In general, the entire recovery process is divided into four parts:(1) pretreatment part; (2) Electrode material repair; (3) leaching of valuable metals; (4) Chemical purification.

In the recycling process, according to the classification of different extraction processes, the recycling technology of lithium-ion batteries can be divided into three categories:(1) dry recovery technology; (2) Wet recovery technology; (3) Biotechnology.

Dry recovery mainly includes mechanical separation and high-temperature thermal solution(or high-temperature metallurgical method). The process of dry recovery is short, and the focus of recovery is not strong. It is the initial stage of metal separation and recovery. It mainly refers to the recovery method of materials or valuable metals without the use of the solution and other media. It is mainly through the physical separation method and the high-temperature thermal solution, the rough screening classification of battery fragmentation, or the high-temperature decomposition to remove organic matter for further The recovery of elements.

Wet recovery technology is relatively complex, but the recovery rate of each valuable metal is relatively high. It is currently the technology that mainly deals with used nickel-metal hydride batteries and lithium-ion batteries. Wet recovery technology uses a variety of acid and alkaline solutions as the transfer medium to transfer metal ions from electrode materials to leaching fluids, and then through ion exchange, precipitation, adsorption, and other means. Metal ions are extracted from the solution in the form of salts, oxides, etc..

Biological recycling technology has the characteristics of low cost, low pollution, and reusable. It is an ideal direction for the development of lithium-ion battery recycling technology in the future. Biological recovery technology mainly uses microbial leaching to convert useful components of the system into soluble compounds and selectively dissolve them to obtain a solution containing effective metals, achieve separation of target components from impurity components, and eventually recover lithium and other valuable metals. At present, the research on biological recovery technology is just beginning, after which it will gradually solve the problem of the cultivation of high-efficiency strains, the length of the cycle, and the control of leaching conditions.

From the order of the recovery process, the first step is the pre-treatment process. The purpose of the pre-treatment process is to initially separate and recover the valuable parts of the old lithium ion battery and to efficiently and selectively enrich the high value-added parts such as electrode materials so as to facilitate the subsequent recovery process. The pretreatment process generally combines fragmentation, grinding, screening and physical separation. The main pre-treatment methods include:(1) predischarge; (2) mechanical separation; (3) Heat treatment; (4) lye solution; (5) Solvent dissolution; (6) Manual dismantling, etc..

Step 2: Material separation. The mixed electrode materials of positive and negative poles were obtained during the pretreatment stage. In order to separate and recover the valuable metals such as Co and Li, selective extraction of the mixed electrode materials was needed. The process of material separation can also be divided into:(1) Inorganic acid leaching according to the classification techniques of dry recovery, wet recovery and biological recovery; (2) Biological leaching; (3) Mechanical chemical leaching.

Step 3: Chemical purification. The purpose is to separate, purify and recycle the various high-value-added metals in the solution obtained by leaching. The leachate contains many elements such as Ni, Co, Mn, Fe, Li, Al, and Cu, among which Ni, Co, Mn, and Li are the main recovered metal elements. After selective precipitation of Al and Fe by adjusting the pH, the elements such as Ni, Co, Mn and Li in the leachate are processed and recovered next. Commonly used recovery methods include chemical precipitation, salt precipitation, ion exchange, extraction, and electrodeposition.

Technology Route and Trend of power battery Recycling in Domestic and Foreign Enterprises: Wet process and high-temperature pyrolysis are the mainstreams compared with the old power battery recycling process of the mainstream battery recycling companies in foreign countries. At present, the mainstream lithium battery recycling process is mainly wet process and high-temperature pyrolysis. And a large part has been put into the industrial production stage.

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