CN-115885409-B - Method for recovering active metal of lithium secondary battery

CN115885409BCN 115885409 BCN115885409 BCN 115885409BCN-115885409-B

Abstract

A method of recovering active metals of a lithium secondary battery includes preparing a primary positive electrode active material mixture from a positive electrode of a waste lithium secondary battery, fluidizing the primary positive electrode active material mixture by an oxygen-containing gas in a fluidized bed reactor to form a positive electrode active material mixture, injecting a reducing gas into the fluidized bed reactor to form a primary precursor mixture from the fluidized positive electrode active material mixture, and recovering lithium precursor from the primary precursor mixture.

Inventors

He xuanpei
Jin Zhimen
SUN CHENGLIE
JIN XUANZHONG
CHENG MINZHI

Assignees

SK新技术株式会社

Dates

Publication Date: 20260512
Application Date: 20210811
Priority Date: 20200818

Claims (14)

1. A method of recovering active metals of a lithium secondary battery, comprising the steps of: Preparing a primary positive electrode active material mixture from a positive electrode of a waste lithium secondary battery; Fluidizing the primary positive electrode active material mixture in a fluidized bed reactor by an oxygen-containing gas to form a positive electrode active material mixture; injecting a reducing gas into the fluidized bed reactor to form a primary precursor mixture from the positive electrode active material mixture, and Recovering lithium precursor from the primary precursor mixture, The step of fluidizing the primary positive electrode active material mixture by the oxygen-containing gas and the step of forming the primary precursor mixture are continuously performed in the fluidized bed reactor.
2. The method for recovering an active metal of a lithium secondary battery according to claim 1, wherein the positive electrode comprises a positive electrode current collector, and a positive electrode active material layer formed on the positive electrode current collector and including a binder, a conductive material, and a positive electrode active material, The step of preparing the primary positive electrode active material mixture includes removing the positive electrode current collector from the positive electrode, The primary positive electrode active material mixture includes the binder, the conductive material, and the positive electrode active material.
3. The method of recovering an active metal of a lithium secondary battery according to claim 2, wherein the step of fluidizing the primary positive electrode active material mixture by the oxygen-containing gas comprises decomposing or combusting the binder and the conductive material in the fluidized bed reactor.
4. The method for recovering an active metal of a lithium secondary battery according to claim 1, wherein the oxygen-containing gas comprises oxygen (O 2 ) and a non-reactive gas, The non-reactive gas includes at least one selected from helium (He), nitrogen (N 2 ), neon (Ne), argon (Ar), krypton (Kr), and xenon (Xe).
5. The method for recovering active metal of a lithium secondary battery according to claim 4, wherein a volume ratio of oxygen is 10-30% by volume and a volume ratio of the non-reactive gas is 70-90% by volume with respect to a total volume of the oxygen-containing gas.
6. The method for recovering active metal of a lithium secondary battery according to claim 1, wherein the step of fluidizing the primary positive electrode active material mixture by the oxygen-containing gas is performed at a temperature of 100-600 ℃.
7. The method of recovering an active metal of a lithium secondary battery according to claim 6, wherein the step of fluidizing the primary positive electrode active material mixture by the oxygen-containing gas comprises raising the temperature from a temperature lower than 50 ℃ to a target temperature in the range of 400-600 ℃ for 1-2 hours.
8. The method of recovering an active metal of a lithium secondary battery according to claim 7, wherein the step of fluidizing the primary positive electrode active material mixture by the oxygen-containing gas comprises heat-treating at the target temperature for 2 to 5 hours.
9. The method for recovering an active metal of a lithium secondary battery according to claim 1, wherein the reducing gas comprises hydrogen.
10. The method of recovering an active metal of a lithium secondary battery according to claim 9, wherein the step of forming the primary precursor mixture is performed at a temperature ranging from 400 to 500 ℃.
11. The method for recovering an active metal of a lithium secondary battery according to claim 1, wherein the step of fluidizing the primary positive electrode active material mixture by the oxygen-containing gas and the step of forming the primary precursor mixture are performed by in-situ means.
12. The method for recovering an active metal of a lithium secondary battery according to claim 9, wherein the primary precursor mixture comprises primary lithium precursor particles and transition metal-containing particles, The transition metal containing particles comprise Ni, co, niO, coO and MnO.
13. The method of recovering an active metal of a lithium secondary battery according to claim 12, wherein the primary lithium precursor particles comprise at least one of lithium hydroxide, lithium oxide, or lithium carbonate.
14. The method for recovering an active metal of a lithium secondary battery according to claim 13, wherein the step of recovering the lithium precursor comprises the step of subjecting the primary lithium precursor particles to a water washing treatment to collect the lithium hydroxide.

Description

Method for recovering active metal of lithium secondary battery Technical Field The present invention relates to a method for recovering active metals of a lithium secondary battery. In more detail, the present invention relates to a method for recovering active metals from a waste positive electrode of a lithium secondary battery. Background The secondary battery is a battery that can be repeatedly charged and discharged, and is widely used in portable electronic communication devices such as camcorders, cellular phones, notebook computers, etc., with the development of information communication and display industries. As the secondary battery, for example, a lithium secondary battery having a high operating voltage and an energy density per unit weight, and being advantageous in terms of charging speed and weight reduction, a nickel-cadmium battery, a nickel-hydrogen battery, and the like are cited, and therefore, lithium secondary batteries have been actively developed and applied. The lithium secondary battery may include an electrode assembly including a positive electrode, a negative electrode, and a separation membrane (separator), and an electrolyte impregnating the electrode assembly. The lithium secondary battery may further include, for example, a soft pack type exterior material accommodating the electrode assembly and the electrolyte. The positive electrode active material of the lithium secondary battery may use lithium metal oxide. The lithium metal oxide may further contain a transition metal such as nickel, cobalt, and manganese. The lithium metal oxide as the positive electrode active material may be prepared by reacting a lithium precursor with a Nickel Cobalt Manganese (NCM) precursor containing nickel, cobalt and manganese. Since the above-mentioned high-cost valuable metal is used in the positive electrode active material, an excessive cost is required for preparing the positive electrode material. In addition, since environmental problems have been highlighted in recent years, a method of recovering a positive electrode active material is being studied. In order to recover the positive electrode active material, it is necessary to regenerate the lithium precursor from the waste positive electrode with high efficiency and high purity. Disclosure of Invention Technical problem to be solved An object of the present invention is to provide a method for recovering active metals of a lithium secondary battery with high efficiency and high purity. Technical proposal In a method of recovering active metals of a lithium secondary battery according to an embodiment of the present invention, a primary positive electrode active material mixture is prepared from a positive electrode of a waste lithium secondary battery, the primary positive electrode active material mixture is fluidized by an oxygen-containing gas in a fluidized bed reactor to form a positive electrode active material mixture, a reducing gas is injected into the fluidized bed reactor to form a primary precursor mixture from the fluidized positive electrode active material mixture, and a lithium precursor is recovered from the primary precursor mixture. In some embodiments, the positive electrode may include a positive electrode current collector, and a positive electrode active material layer may be formed on the positive electrode current collector and include a binder, a conductive material, and a positive electrode active material. The step of preparing the primary positive electrode active material mixture may include removing the positive electrode current collector from the positive electrode. The primary positive electrode active material mixture may include the binder, the conductive material, and the positive electrode active material. In some embodiments, the step of fluidizing the primary positive electrode active material mixture by the oxygen-containing gas may include decomposing or combusting the binder and the conductive material in the fluidized bed reactor. In some embodiments, the oxygen-containing gas may comprise oxygen (O 2) and a non-reactive gas. The non-reactive gas may include at least one selected from helium (He), nitrogen (N 2), neon (Ne), argon (Ar), krypton (Kr), and xenon (Xe). In some embodiments, the volume ratio of oxygen may be 10 to 30% by volume and the volume ratio of the non-reactive gas may be 70 to 90% by volume relative to the total volume of the oxygen-containing gas. In some embodiments, the step of fluidizing the primary positive electrode active material mixture by the oxygen-containing gas may be performed at a temperature of 100 to 600 ℃. In some embodiments, the step of fluidizing the primary positive electrode active material mixture by the oxygen-containing gas may include increasing the temperature from a temperature below 50 ℃ to a target temperature in the range of 400-600 ℃ for 1-2 hours. In some embodiments, the step of forming the primary positive electrode active material