WO2019205984A1

WO2019205984A1 - Method for recycling of positive electrode plates from lithium-ion battery

Info

Publication number: WO2019205984A1
Application number: PCT/CN2019/082844
Authority: WO
Inventors: Linjian ZHU; Yunfeng Li; Yongfeng Zhao; Fei Xu; Hongtao Ma; Yaqiong NI; Hongjuan Zhao; Xingdan LIU; Qian Tan; Ming Li
Original assignee: Do Fluoride New Energy Tech Co Ltd
Priority date: 2018-04-27
Filing date: 2019-04-16
Publication date: 2019-10-31
Also published as: CN108470955A

Abstract

A method for recycling of positive electrode plates from lithium-ion battery is provided. The method includes the following procedures: the scrapped positive electrode plates are undergone heat treatment at about 250~400°C; after the heating treatment positive electrode material and fragments of the plates are separated by vibration sieving; then the plate fragments are immersed into organic solvents to further separate into current collector fragments and positive electrode material slurry. To provide a method for recycling of positive electrode plates, the scrapped positive electrode plates are initially treated by heating, then approximately 80% of the positive electrode material can be removed through vibration sieving. This method is efficient in removal of positive electrode material; therefore, it offers high efficiency in recycle of positive electrode material.

Description

[Title established by the ISA under Rule 37.2] METHOD FOR RECYCLING OF POSITIVE ELECTRODE PLATES FROM LITHIUM-ION BATTERY

TECHNICAL FIELD

This disclosure relates to the field of recycling of lithium-ion battery and specifically relates to the method for recycling of the positive electrode plates from lithium-ion battery.

BACKGROUND

Lithium-ion battery is a new type of electrochemical power supply. It caters to the requirements of the development of modern electronic products, with features of high energy density, high voltage, non-pollutant, environmentally friendly, long cycle life, no memory effect, fast charging, etc. Presently Lithium-ion batteries are widely used for personal computer, cell phones, portable electronics and so on.

There are large amounts of fragmented and scrapped positive electrode platess generated during the production process of Lithium-ion battery, also daily life usages produce large amount of discarded batteries. The positive electrode plates of batteries, if not recycled but discarded directly, will not only become environmental pollutant that is difficult to process, but also causes difficulty to lower production cost. It is important to develop a method for recycling of positive electrode plates with high efficiency and at low cost.

Patent No. CN101212074B published a method for recycling positive electrode plates from lithium-ion battery. It utilizes a mixed solvent of N, N-dimethylformamide and liquid alcohol/liquid ketone to soak positive electrode plates, separating the positive electrode material from the current collector, which are then removed, the active material of positive electrode is recovered through filtering followed by drying.

Conventional methods for recycling positive electrode plates mainly use heated organic solvent to remove the positive electrode material from the current collector, such method exhibits low efficiency in removal, for which improvements in recycling efficiency and time are left much to be desired.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1: Process Flow Diagram of Recycling of Positive Electrode Plates from Lithium-ion Battery

DETAILED DESCRIPTION

The following is a detailed explanation of the implementation of the invented method for certain embodiments. The scrapped positive electrode plates may be made of ternary cathode, where the active substance is ternary cathode material, and the binder may be a Polyvinylidene fluoride (PVDF) .

The following cases, as illustrated in Figure 1, utilize the automated process system for recycling the positive electrode plates, . Such system may comprise, in sequential connection, acutting apparatus 1, a baking device 2, a vibration screening 4, and an ultrasonic agitation 3. The cutting apparatus 1 consists of a cutter 10 and an associated conveyor belt 12 for transferring the scrapped electrode plates 11. The baking device 2 may include a receiver box 20 for the collection of small fragments of scrapped electrode plates upon cutting, and an oven 21 for baking small fragments of the electrode plates. The outlet of the oven 21 may connect to the ultrasonic agitation device 3 through the vibration screening device 4.

In an embodiment, the procedures of the recycling method of the positive electrode plates from lithium-ion battery are as follows:

1) Cutting discarded positive electrode plates from the production line into small fragments, preferably about 1 cm in diameter, which are then heated to about 300℃ for about three hours. Subsequently, the fragments are placed in the vibration screen with a mesh diameter of about 1 mm. Upon vibration sieving the ternary cathode material and the current collector, are separated so that ternary cathode material powder is below the sieve or vibration screen, and fragmented electrode plates are above the sieve;

2) Placing the separated fragmented electrode plates in the ultrasonic agitation device, then adding NMP solvent (N-Methyl-2-pyrrolidone) , the separated fragmented electrode plates are treated under agitation and ultrasonic wave. The agitation speed is preferably about 100 r/min, the frequency of the ultrasonic wave is preferably about 30 kHz. The material may be treated for about two hours. . The treated mixture may be then coarsely filtered to separate any aluminum foil from the positive electrode material slurry;

3) The cathode material slurry may be dried in an oven at about 110℃ to recover the residual ternary cathode material. The NMP solvent may be recycled during the drying process for reuse.

In a second embodiment, the procedures of the recycling method of the positive electrode plates from lithium-ion battery are as follows:

1) Cutting the scrapped positive electrode plates from lithium-ion batteries into small fragments of about 1 cm in diameter, and then they are heated at about 250℃ for about four hours. Subsequently, the fragments are placed in the vibration screen with mesh diameter of about 1 mm. Upon vibration sieving the ternary cathode material and the current collector are separated, so that ternary cathode material powder is below the sieve, or vibration screen, and fragmented electrode plates are above the sieve.

2) Placing the separated fragmented electrode plates in the ultrasonic agitation device, then adding NMP solvent, the separated fragmented electrode plates are treated under agitation and ultrasonic wave. The agitation speed is preferably about 120 r/min, and the frequency of the ultrasonic wave is preferably about 30 kHz. The material may be treated for about three hours. The treated mixture may then be coarsely filtered to separate any aluminum foil from the positive electrode material slurry;

3) The cathode material slurry may be dried in an oven at 100℃ to recover the residual ternary cathode material and the NMP solvent may be recycled during the drying process for reuse.

In a further embodiment, the procedures of the recycling method of the positive electrode plates from lithium-ion battery are as follows:

1) Cutting the scrapped positive electrode plates from lithium-ion batteries into small fragments of about 1 cm in diameter, and then they are heated at about 400℃ for about two hours. Subsequently, the fragments are placed in the vibration screen with mesh diameter of about 1 mm. Upon vibration sieving the ternary cathode material and the current collector are separated, so that ternary cathode material powder is below the sieve, or vibration screen and fragmented electrode plates are above the sieve;

2) Placing the separated fragmented electrode plates in the ultrasonic agitation device, then adding an acetone solvent, the separated fragmented electrode plates are treated under agitation and ultrasonic wave. The agitation speed is preferably about 150 r/min, and the frequency of the ultrasonic wave is about 25 kHz. The material may be treated for about four hours. The treated mixture may then be coarsely filtered to separate any aluminum foil from the positive electrode material slurry;

3) The cathode material slurry may be dried in an oven at 200℃ to recover the residual ternary cathode material, and the acetone solvent may be recycled during the drying process for reuse.

The capacity and cycle performance of the lithium-ion battery manufactured from the ternary cathode material recovered by the presented invention and used as raw material for the production of lithium-ion batteries have been found to be comparable to those from normal production. The invention provides a method for recycling of positive electrode plates; the scrapped positive electrode plates are initially treated by heating, then approximately 80%of the positive electrode material can be removed through vibration sieving.

Although the disclosed subject matter has been described and illustrated in the foregoing exemplary embodiments, it is understood that the present disclosure has been made only by way of example, and that numerous changes in the details of implementation of the disclosed subject matter may be made without departing from the scope of the disclosed subject matter.

Claims

A method for recycling of positive electrode plates from the lithium-ion batteries comprising:

heating the positive electrode plates to about 250–400℃, then cathode material and plate fragments are separated using a vibration screen;

immersing the plate fragments in organic solvents, so that current collector fragments and cathode material slurry are separated;
The method ofclaim 1, wherein, the diameter of the holes in the vibration screen are between 1 and 2 mm.
The method of claims 1 or 2, wherein, the organic solvent is N-Methyl-2-pyrrolidone (NMP) or Acetone.
The method of any one of claims 1 to 3, wherein, immersing further comprises ultrasonic treatment.
The method of any one of claims 1 to 4 wherein, the duration of immersion treatment is between 3 and 5 hours.
The method of any one of claims 1 to 5 further comprising, drying the positive electrode material slurry.
The method of any one of claims 1 to 6 wherein, the duration of heat treatment is between 2 and 4 hours.
The method of any one of claims 1 to 7 wherein, the positive electrode plates are from disassembled lithium-ion batteries and/or discard from the production line.
The method of any one of claims 1 to 8 wherein the fragmented positive electrode plates are from cutting of the scrapped positive electrode plates.