| In recent years,with the widespread use of lithium-ion batteries in the field of electronic products and electric vehicles,waste lithium-ion batteries have been produced in large quantities.How to realize the recycling of waste lithium-ion batteries has become an important issue in the face of sustainable industrial development.At present,wet technology has become the mainstream process for recycling valuable metal elements in waste lithium-ion batteries,but it is still difficult to recover lithium from waste lithium battery leaching solution.Based on the principle of molecular recognition,this paper uses a crown ether compound that selectively recognizes lithium ions to effectively extract and separate lithium ions from the leachate.The main contents are as follows:(1)Two kinds of crown ether compounds,benzo-15-crown-5(B15C5)and dibenzo-14-crown-4(DB14C4),which have good selectivity to lithium ions,were screened by quantum chemistry calculation of interaction between crown ether compounds with different structures and metal ions in leachate.Thermo dynamic calculations show that these two crown ether compounds are capable of efficiently extracting lithium from aqueous solutions containing lithium,cobalt,nickel and manganese.(2)Using styrene synthesis method,benzo-15-crown-5 was synthesized from catechol and diethylene glycol bis-(2-chloroethyl)ether,and the yield was 70%.In order to verify the selectivity of benzo-15-crown-5 to lithium,an extraction experiment was carried out and the optimal extraction conditions were obtained:pH=6,temperature 30 °C,extraction time 2 h,extraction rate 37.23%.(3)Dibenzo-14-crown-4 was synthesized from the raw materials of catechol and1,3-dibromopropane by template synthesis,and the yield was 35.44%.The extraction experiment of dibenzo-14-crown-4 on lithium was carried out.The results showed that the extraction rate of lithium was 23.37% under the conditions of pH=0,temperature 30 °C and extraction time of 1 h. |
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