CN-122000339-A - Separation and repair method for heterogeneous positive electrode black powder material

CN122000339ACN 122000339 ACN122000339 ACN 122000339ACN-122000339-A

Abstract

The invention provides a separation and repair method of a heterogeneous positive electrode black powder material, which comprises the following steps of carrying out carbonization heat treatment on the heterogeneous positive electrode black powder material to obtain a carbonized heterogeneous positive electrode black powder material, mixing the carbonized heterogeneous positive electrode black powder material with a density heavy liquid, carrying out cyclone separation treatment to obtain a heavy product and a light product respectively, mixing the heavy product with a lithium source, carrying out lithiation calcination treatment to obtain a nickel cobalt lithium manganate positive electrode material, carrying out oxidation sintering treatment on the light product to obtain a sintering material, mixing the sintering material with a carbon source and a lithium source, and carrying out heat reduction treatment to obtain a lithium iron phosphate positive electrode material, wherein the heterogeneous positive electrode black powder material comprises a mixed material of ternary nickel cobalt lithium manganate positive electrode material black powder and lithium iron phosphate positive electrode material black powder. In the separation and repair method, no strong acid, strong alkali or waste liquid is generated, no heavy metal is lost, the efficient recovery and utilization of key elements on the material level are realized, and the dense heavy liquid and the water for washing can be recycled.

Inventors

CHEN WEN
Duan Xixiong
WENG WEI
Wei Zhining
ZHANG CHAOSHAN
WANG CHAO
YANG JINGLONG
Xi Jiayao
LI LELE

Assignees

杭州科技职业技术学院(杭州开放大学、杭州远程教育中心、杭州社区大学、杭州市民大学、杭州广播电视中等专业学校)

Dates

Publication Date: 20260508
Application Date: 20260407

Claims (10)

1. The separation and repair method of the heterogeneous positive electrode black powder material is characterized by comprising the following steps of: Performing carbonization heat treatment on the heterogeneous positive electrode black powder material to obtain a carbonized heterogeneous positive electrode black powder material; Mixing carbonized heterogeneous anode black powder material with density heavy liquid, and performing cyclone separation treatment to obtain a heavy product and a light product respectively; mixing the heavy product with a first lithium source, and carrying out lithiation calcination treatment to obtain a ternary nickel cobalt lithium manganate anode material; Oxidizing and sintering the light product to obtain a sintering material, mixing the sintering material, a carbon source and a second lithium source, and performing thermal reduction treatment to obtain a lithium iron phosphate anode material; the heterogeneous positive electrode black powder material comprises a mixed material of ternary nickel cobalt lithium manganate positive electrode material black powder and lithium iron phosphate positive electrode material black powder.
2. The separation repair method of claim 1, wherein the carbonization heat treatment atmosphere comprises nitrogen and/or argon; and/or the temperature of the carbonization heat treatment is 450-720 ℃.
3. The separation repair method of claim 1, wherein the dense heavy liquid comprises a ferrosilicon heavy suspension and/or an aqueous sodium polytungstate solution; And/or the density of the dense liquid is 2.8g/cm 3 ~4g/cm 3 .
4. The separation and repair method according to claim 1, wherein the mass ratio of the carbonized heterogeneous anode black powder material to the dense heavy liquid is (5-20): 100.
5. The separation and repair method according to claim 1, wherein the cyclone separation treatment is followed by filter pressing and drying of the obtained heavy and light products, respectively.
6. The separation repair method of claim 1 wherein the first lithium source comprises any one or a combination of at least two of lithium hydroxide, lithium carbonate, or lithium oxalate.
7. The separation repair method of claim 1, wherein the lithiation calcination treatment atmosphere comprises an oxygen-containing atmosphere; And/or the lithiation and calcination temperature is 650-750 ℃; And/or the lithiation and calcination time is 2-5 hours.
8. The separation repair method of claim 1, wherein the atmosphere of the oxidative sintering treatment comprises an oxygen-containing atmosphere; and/or the temperature of the oxidation sintering treatment is 400-600 ℃; And/or the time of the oxidation sintering treatment is 1-3 hours.
9. The separation and repair method of claim 1, wherein the carbon source comprises any one or a combination of at least two of glucose, sucrose, or urea; And/or the mass ratio of the sintering material to the carbon source is 1 (0.03-0.15); And/or the second lithium source comprises any one or a combination of at least two of lithium hydroxide, lithium carbonate or lithium oxalate; and/or the mass ratio of the sintering material to the second lithium source is 100 (1-3).
10. The separation and repair method according to claim 1, wherein the atmosphere of the thermal reduction treatment includes a hydrogen-containing protective gas; And/or the temperature of the thermal reduction treatment is 550-660 ℃; And/or the time of the thermal reduction treatment is 1-3 h.

Description

Separation and repair method for heterogeneous positive electrode black powder material Technical Field The invention belongs to the technical field of resource recycling, and relates to a separation and repair method of a heterogeneous positive electrode black powder material. Background With the rapid development of new energy automobile industry and the rapid increase of market conservation, the power battery industry in China is increased in scale. However, after a large number of batteries are put into service and gradually reach the design life, the number of retired batteries produced each year is growing geometrically. If the huge waste resources cannot be efficiently and environmentally-friendly treated, the soil and the water body are permanently polluted by the contained heavy metal, electrolyte and other components, and the key strategic metal resources such as lithium, cobalt, nickel and the like are seriously lost. Therefore, the construction of a large-scale and green waste power battery recovery system and the promotion of high-quality recycling regeneration of the waste power battery have become urgent tasks related to resource safety and sustainable development of the environment. At present, the recycling of the failed lithium ion battery mainly follows three technical paths of pyrometallurgy, hydrometallurgy and direct repair. The fire method and the wet method have earlier process development and relatively mature technology, but generally have long flow, high energy consumption and complicated wastewater and waste gas treatment problems, and are under pressure on economic and environmental cost. In contrast, the direct repair technology is an emerging method based on material structure reactivation and chemical lithium supplementation, and directly restores the electrochemical performance of the anode material through a mild physicochemical process, and has the distinct advantages of short flow, remarkably reduced energy consumption and emission and high resource utilization rate. The technology not only accords with the development direction of green manufacturing and circular economy, but also can effectively shorten the regeneration period and reduce the dependence on primary mineral products, so the technology is regarded as a key break for pushing the battery recovery industry to convert and upgrade to low carbon and high efficiency, and has extremely important strategic significance and application prospect. In the existing large-scale recovery process, the waste batteries are usually subjected to pretreatment steps such as crushing, screening and the like to obtain valuable components mainly containing electrode materials. However, the failure electrode material produced by industrial recycling is essentially a multiphase mixture containing a plurality of components such as positive electrode active material, negative electrode active material, conductive agent, binder and residual electrolyte, commonly known as "black powder". The highly complex physical and chemical composition causes remarkable differences of each component in microstructure, surface property and reactivity, thereby forming fundamental constraint on the suitability and stability of the direct repair process and becoming a main technical barrier for the technology to be applied to engineering. Particularly, under the drive of the current new energy automobile pursuing high energy density and long endurance mileage, in order to take the performance advantages of different anode materials into consideration, battery enterprises increasingly adopt a composite anode system, namely, two or more anode materials are mixed according to a specific proportion. For example, the combination of high specific capacity nickel cobalt lithium manganate (NCM) and high safety lithium iron phosphate (LFP) can improve the comprehensive performance of the battery core, but brings serious challenges for subsequent direct repair, namely, NCM and LFP are different in crystal structure and lithium diffusion mechanism, the thermodynamic environment required for synthesis and regeneration is completely opposite, NCM is usually required to be stably existing in an oxidizing atmosphere and repaired by lithium supplementation, and LFP is required to prevent oxidation of iron element and maintain structural integrity in an inert or reducing atmosphere. If the two materials are directly mixed for high-temperature regeneration treatment, mutual interference is easy to occur, so that the phase change of the materials, the irreversible change of the structure, the aggravation of surface side reactions and the irreversible attenuation of the electrochemical performance are caused. Therefore, developing high-efficiency and accurate preamble separation technology to realize ordered separation and enrichment of heterogeneous positive electrode materials has become a core premise for breaking through the direct repair technology bottleneck of mixed b