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Title：What are the methods for treating waste lithium ion battery electrolyte?
What are the methods for treating waste lithium ion battery electrolyte? How to treat the electrolyte of waste lithium battery? He Cheng Xiaobian talked with you about the treatment method of waste lithium ion battery electrolyte.
1、 Why should lithium ion battery electrolyte be recycled?
Lithium ion batteries contain a lot of heavy metals and electrolytes. Recycling useful components from waste lithium ion batteries has become an emerging industry.
The output of lithium-ion batteries has maintained a strong growth trend, and the number of lithium-ion batteries scrapped after the service life will increase year by year. The lithium-ion batteries contain 5% - 20% diamond, 5% - 10% nickel, 5% - 7% lithium, and 15% organic compounds and 7% plastic.
The electrolyte in lithium-ion batteries is difficult to recover due to its liquid and volatile nature. At present, the common recovery of waste lithium-ion battery electrolyte is mainly focused on the recovery of valuable metals, including non-ferrous metals such as diamond, lithium, nickel, copper, and other electrode materials with high value.
Electrolyte is volatile and difficult to recover. Few researches and treatment are conducted specifically for electrolyte recovery. However, the volatilization of the electrolyte will produce unpleasant and irritating odor, and the lithium salt in the electrolyte will hydrolyze to produce toxic arsenide, phosphide and fluoride, which are very harmful to human body and the environment. From the perspective of environmental protection, it should be treated. Recycling and disposal of waste lithium ion batteries can not only eliminate pollution sources, but also realize the recovery and reuse of resources.
2、 Electrolyte characteristics of waste lithium ion batteries
The electrolyte in waste lithium-ion batteries is mainly composed of the following three kinds of substances:
1. Organic solvent. Widely used include propylene carbonate (PC), ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl alunite (DMSO), dimethyl carbonate (DMC), methyl ethyl carbonate, etc.
2. Electrolyte lithium salt. For example, lithium hexafluoroarsenate (LiAsF.), lithium perchlorate (LiCIO,), lithium tetrafluoroborate (LiBF), lithium hexafluorophosphate (LiPF.), lithium bis (trifluoromethylsulfonyl) imide (LiN (CF, SO,) 2), LiCF, SO, Li (SO, CF) 2
3. Additives. Electrolyte additives can improve the performance of SEI film, improve the conductivity of electrolyte, low temperature performance, cycle stability, and improve battery performance. There are many kinds of additives, such as vinyl carbonate (VC), lithium oxalate borate (LiBOB), ethyl acetate (EA), biphenyl (BP), fluoroethylene carbonate (FEC), succinonitrile (SN), etc.
3、 The treatment of waste lithium-ion battery electrolyte can be roughly divided into two technical routes:
1. Fire treatment means that the battery or broken battery is treated at high temperature. If air or oxygen is introduced in the process, the electrolyte will volatilize and be oxidized and burned, and the flue gas shall be treated innocuously. The electrolyte cannot be recycled by this method; If this process is carried out under vacuum or inert gas protection, the electrolyte will decompose at high temperature, and generally cannot be reused as electrolyte, but can be used as fuel.
2. The physical method is to separate the electrolyte from the battery by freezing, distillation, centrifugation, extraction and other non-destructive methods. The electrolyte can be recycled by this method.
