CN-122025893-A - Waste lithium ion battery electrolyte recovery process and equipment

CN122025893ACN 122025893 ACN122025893 ACN 122025893ACN-122025893-A

Abstract

The invention provides a waste lithium ion battery electrolyte recovery process and equipment, and relates to the technical field of solid waste recycling treatment, comprising the following steps of S1, decomposing a fully discharged waste lithium ion battery in an inert gas glove box, removing scraps such as adhesive tapes, immersing in a dimethyl carbonate solution, carrying out ultrasonic stirring, standing and filtering to obtain a mixed solution; and S2, transferring the mixed solution into a vacuum distillation device for distillation to obtain dimethyl carbonate and electrolyte, wherein the dimethyl carbonate can be circularly used for extracting other waste electrolyte. According to the scheme, the efficient recovery of the electrolyte is realized through the extraction of the dimethyl carbonate and the vacuum distillation, the lithium salt is recovered in the form of lithium fluoride, the key metal recovery of the lithium battery is realized, the fluoride and the phosphate can be reused as high-purity products, the resource utilization efficiency is improved, and the emission of toxic gas is avoided.

Inventors

YU JINXIANG
WANG XIAOMAO
WEI DONGDONG
YAO LI
PAN RUI
Zhan Daowu
ZHU GUANGJIE
YAN CHANGQING
NAN NING
SHUAI JUN

Assignees

江西九岭锂业股份有限公司

Dates

Publication Date: 20260512
Application Date: 20260226

Claims (8)

1. The waste lithium ion battery electrolyte recovery process is characterized by comprising the following steps of: S1, decomposing the completely discharged waste lithium ion battery in an inert gas glove box, removing scraps such as adhesive tapes, immersing the waste lithium ion battery in a dimethyl carbonate solution, ultrasonically stirring, standing and filtering to obtain a mixed solution; s2, transferring the mixed solution into a vacuum distillation device for distillation to obtain dimethyl carbonate and electrolyte, wherein the dimethyl carbonate can be circularly used for extracting other waste electrolyte; Step S3, mixing the electrolyte with deionized water, oscillating and filtering to obtain lithium fluoride precipitate and mixed filtrate; S4, carrying out oil-water phase separation on the mixed filtrate to obtain an oil phase and an aqueous phase containing H 3 PO 4 and HF, wherein the oil phase can be treated by vacuum distillation and a molecular sieve to remove residual water and HF, so as to obtain a purified organic solvent; S5, adding a calcium hydroxide solution into the aqueous phase containing H 3 PO 4 and HF, and continuously stirring to obtain CaF 2 and Ca 3 (PO4) 2 coprecipitate; S6, mixing the co-precipitate in powder particles with hydrochloric acid in a reaction tank, stirring, and filtering to obtain CaF 2 precipitate and filtrate; step S7, adding a calcium hydroxide solution into the filtrate for reaction, filtering, washing, drying and grinding to obtain Ca 3 (PO 4 ) 2 precipitate; And S8, adding the corresponding solvent and the LiPF 6 into the purified organic solvent obtained in the step S4, uniformly mixing, and preparing the regenerated electrolyte of the LiPF 6 in an argon-filled glove box.
2. The waste lithium ion battery electrolyte recycling device is characterized by being used for the waste lithium ion battery electrolyte recycling process according to claim 1 and comprising a reaction tank, a sealing plate, a reciprocating mechanism and a feeding mechanism; The reciprocating mechanism comprises two belt pulleys which are vertically and rotatably connected to the bottom of the sealing plate through a rotating shaft, belts are sleeved on the surfaces of the two belt pulleys, a driving motor for driving the belt pulleys to rotate is arranged on the left side of the top of the sealing plate, and the bottom of the sealing plate is fixedly connected with the top of the reaction tank; The feeding mechanism comprises two sliding rails fixedly arranged at the bottom of the sealing plate, the surfaces of the sliding rails are slidably connected with sliding frames, the sliding frames are fixedly connected with a belt, a feeding cylinder is fixedly arranged at the bottom of the sliding frames, a first sliding support is vertically and slidably connected with the inside of the feeding cylinder, a first rotating wheel is rotatably connected with the inner side of the top of the first sliding support, a convex plate is fixedly arranged at the bottom of the sealing plate, the top of the first rotating wheel is in contact with the bottom of the convex plate, a spring is sleeved on the surface of the first sliding support and positioned at the top of the feeding cylinder, and a movable cone is rotatably connected with the bottom of the first sliding support.
3. The waste lithium ion battery electrolyte recycling device according to claim 2, wherein a convex platform is arranged on the right side of the convex plate, the top of the movable cone is cone-shaped, the bottom of the movable cone is cylinder, and the diameter of the cylinder at the bottom of the movable cone is slightly smaller than the diameter of the outlet at the bottom of the charging barrel.
4. The waste lithium ion battery electrolyte recycling device according to claim 2, wherein the inside of the sealing plate is vertically and rotatably connected with a knocking mechanism, the knocking mechanism comprises a rotating shaft vertically and rotatably connected with the inside of the sealing plate, a driving disc is fixedly arranged on the peripheral side surface of the rotating shaft, a guide rail is fixedly arranged at the bottom of the sealing plate, a reciprocating seat is slidably connected with the surface of the guide rail, a guide rod is fixedly arranged on the inner side of the guide rail, the reciprocating seat is slidably connected with the guide rod, a reset spring is sleeved on the surface of the guide rod and positioned on the left side of the reciprocating seat, a movable support is fixedly arranged at the bottom of the reciprocating seat, a driving wheel is rotatably connected with the bottom of the movable support, the driving wheel is in contact with the peripheral side surface of the driving disc, and the knocking support is fixedly arranged at the bottom of the movable support.
5. The waste lithium ion battery electrolyte recycling device according to claim 4, wherein the cleaning mechanism is fixedly arranged at the top of the movable support, the cleaning mechanism comprises a driving plate fixedly arranged at the top of the movable support, a second sliding support is vertically and slidably connected to the inside of the sealing plate, a second rotating wheel is rotatably connected to the inner side of the bottom of the second sliding support, the bottom of the second rotating wheel is in contact with the top of the driving plate, a buffer spring is sleeved on the surface of the second sliding support and positioned at the bottom of the sealing plate, an air cylinder is fixedly arranged at the top of the sealing plate, the peripheral side surface of the top of the second sliding support is in sliding connection with the air cylinder, and a piston is fixedly arranged at the top end of the second sliding support and positioned inside the air cylinder.
6. The waste lithium ion battery electrolyte recycling device according to claim 2, wherein a feeding mechanism is fixedly arranged on the left side of the inner wall of the reaction tank and comprises a T-shaped frame fixedly arranged on the left side of the inner wall of the reaction tank, a tooth group is fixedly arranged on the back surface of the T-shaped frame, a rotating gear is fixedly arranged at the bottom of the movable cone through a rotating shaft, a stirring plate is fixedly arranged on the surface of the movable cone, and two feeding pipes are vertically arranged on the inner side of the sealing plate.
7. The waste lithium ion battery electrolyte recycling device according to claim 4, wherein a mixing mechanism is fixedly arranged on the surface of the rotating shaft and comprises a plurality of mixing paddles fixedly arranged on the surface of the rotating shaft, an installation seat is fixedly arranged at the top of the sealing plate, and a mixing motor for driving the rotating shaft to rotate is arranged at the top of the installation seat.
8. The waste lithium ion battery electrolyte recycling device according to claim 2, wherein two sides of the reaction tank are respectively communicated with a liquid inlet pipe, two exhaust pipes are vertically arranged in the sealing plate, a discharge pipe is communicated with the left side of the bottom of the reaction tank, and two supporting seats are fixedly arranged at the bottom of the reaction tank.

Description

Waste lithium ion battery electrolyte recovery process and equipment Technical Field The invention relates to the field of solid waste recycling treatment, in particular to a waste lithium ion battery electrolyte recovery process and equipment. Background Along with the increasing severity of global energy and environmental problems, lithium ion batteries are widely applied in the fields of electric automobiles, portable electronic equipment, energy storage systems and the like due to the advantages of high energy density, long cycle life, environmental protection and the like. However, with the rapid increase of the production capacity and the demand of lithium ion batteries, the number of waste lithium ion batteries is also rapidly increased, and if the waste lithium ion batteries are improperly treated, not only is the waste of resources caused, but also serious pollution is caused to the environment. At present, the recovery of the waste lithium ion battery is mainly concentrated on the recovery of anode and cathode materials, and the recovery and utilization research of electrolyte is relatively less. The electrolyte is used as an important component of the lithium ion battery and mainly comprises lithium salt (such as lithium hexafluorophosphate and LiPF 6), organic solvent (such as ethylene carbonate, EC, dimethyl carbonate, DMC and the like) and additives, and the recycling and reutilization of the electrolyte have remarkable economic and environmental benefits. However, lithium salts in the electrolyte are prone to react with water to form toxic gases (e.g., hydrofluoric acid, HF), and organic solvents are toxic and volatile, making recycling of the electrolyte a technical challenge. Therefore, it is necessary to provide a process and equipment for recovering the electrolyte of the waste lithium ion battery to solve the technical problems. Disclosure of Invention The invention provides a waste lithium ion battery electrolyte recovery process and equipment, which solve the problems that lithium salt in the electrolyte is easy to react with water to generate toxic gas and an organic solvent has toxicity and volatility when the waste lithium ion battery electrolyte is recovered at present. In order to solve the technical problems, the waste lithium ion battery electrolyte recovery process provided by the invention comprises the following steps: S1, decomposing the completely discharged waste lithium ion battery in an inert gas glove box, removing scraps such as adhesive tapes, immersing the waste lithium ion battery in a dimethyl carbonate solution, ultrasonically stirring, standing and filtering to obtain a mixed solution; s2, transferring the mixed solution into a vacuum distillation device for distillation to obtain dimethyl carbonate and electrolyte, wherein the dimethyl carbonate can be circularly used for extracting other waste electrolyte; Step S3, mixing the electrolyte with deionized water, oscillating and filtering to obtain lithium fluoride precipitate and mixed filtrate; S4, carrying out oil-water phase separation on the mixed filtrate to obtain an oil phase and an aqueous phase containing H 3PO4 and HF, wherein the oil phase can be treated by vacuum distillation and a molecular sieve to remove residual water and HF, so as to obtain a purified organic solvent; S5, adding a calcium hydroxide solution into the aqueous phase containing H 3PO4 and HF, and continuously stirring to obtain CaF 2 and Ca 3(PO4)2 coprecipitate; S6, mixing the co-precipitate in powder particles with hydrochloric acid in a reaction tank, stirring, and filtering to obtain CaF 2 precipitate and filtrate; step S7, adding a calcium hydroxide solution into the filtrate for reaction, filtering, washing, drying and grinding to obtain Ca 3(PO4)2 precipitate; And S8, adding the corresponding solvent and the LiPF 6 into the purified organic solvent obtained in the step S4, uniformly mixing, and preparing the regenerated electrolyte of the LiPF 6 in an argon-filled glove box. The electrolyte recycling equipment for the waste lithium ion batteries comprises a reaction tank, a sealing plate, a reciprocating mechanism and a feeding mechanism; The reciprocating mechanism comprises two belt pulleys which are vertically and rotatably connected to the bottom of the sealing plate through a rotating shaft, belts are sleeved on the surfaces of the two belt pulleys, a driving motor for driving the belt pulleys to rotate is arranged on the left side of the top of the sealing plate, and the bottom of the sealing plate is fixedly connected with the top of the reaction tank; The feeding mechanism comprises two sliding rails fixedly arranged at the bottom of the sealing plate, the surfaces of the sliding rails are slidably connected with sliding frames, the sliding frames are fixedly connected with a belt, a feeding cylinder is fixedly arranged at the bottom of the sliding frames, a first sliding support is vertically and slidably connected wit