Three yuan charging lithium battery ‘retired tide’ back: is the carnival of wet recycling technology

Three yuan charging lithium battery 'retired tide' back: is the carnival of wet recycling technology

Retired battery electrode material recycling, imminent. With the rapid rise of the three-yuan lithium-ion battery market, the retired three-dimensional lithium-ion battery has burst rising, so the recovery of the three-yuan lithium-ion battery electrode material into a new focus of the battery industry..

Under the dual stimulation of national industrial policies and market demand, the output of three-yuan material has continued to rise. With the development of my country’s new energy automotive industry, and the requirements of high-energy density have a three-yuan material with high energy density in the development of China’s new energy automotive industry, and the requirements of electric vehicle battery life. Widely used, future three-yuan lithium-ion battery market share will further increase.

Lithium-ion batteries, especially new energy vehicles dynamic lithium battery life is usually three to five years, and CO, LI and NI in ternary lithium-ion batteries are higher value of metal.. Therefore, recovery after retiring the powerful lithium battery will have a considerable economic benefit and social benefits.

. At present, the retired lithium-ion battery material recycles is important into two major categories of fire-based metallurgy and wet metallurgy..

Fire mimetallurgy is a method of extracting metal or metal oxide in the electrode directly using high temperature treatment, is simple, but the recovery material is low, the electrolyte, and the organic matter such as electrolyte, binder, such as the electrolyte, and the high temperature reactive gas, to install Supported facilities for secondary exhaust gas treatment. Wet metallurgy is first dismantled the battery case, broken, sieved, and obtains the electrode material in the electrode material in an acid or biological solution, and then separates, obtains each metal corresponding salt or oxide..

Wet recovery operation conditions are mild, and the metal recovery is high, less product impurities, the recovery product can directly enter the production of new electrode materials, and realize the closed cycle of the viable metal material, so it has become a research hot spot at home and abroad.. So, what is the step of retreating a dual lithium-ion battery material wet recovery? An important step of the retardation of a residential lithium-ion battery electrode wet reclamation includes pre-treatment, pretreatment, leaching, and separation extraction, viable metal, etc.

. The former treatment is a physical discharge and dismantling of retired ternary batteries..

If the retired lithium-ion battery charge state is uneven, there will be different levels of electricity residues.. Lithium-ion batteries are in charge, and the dismantling is relatively hazardous, and therefore, from the perspective of safety, it is sufficiently discharged before the battery is disassembled.

. At present, there are two ways to discharge the decommissioning battery, one is to perform physical discharge on the charge and discharge device; the second is sufficiently discharged in a concentration of salt solution..

A typically lithium-ion battery pack is covered by a plastic shell, and the monomer lithium ion battery is covered by a metal casing or an aluminum-plastic film, and the sufficiently discharged battery pack is divided into a monomer battery, and the monomer battery is again selected from the battery. Shell, electrode, diaphragm, etc..

Dissolving part, currently with more manual disassembly, less material impurities, recycled products, low efficiency, small processing volume, dangerous. Pretreatment is the electrode active material and the collector separation, but the electrode contains not only the active material, but also a material such as a conductive carbon, a binder, and a current collector, but also pretreatment, and separating the active material and the current fluid to obtain a viable metal. Solid powder, conducive to subsequent leaching.

Commonly used pretreatment methods include heat treatment method, mechanical separation, solvent method and alkali solvent. The heat treatment method is to decompose the temperature of each substance in the electrode material, which causes the bond to decompose by high temperature, and the active substance is detached from the collector..

The heat treatment method is simple, and the active substance and aluminum foil can be effectively separated, and less impurities introduced by the recovered active material, high purity, suitable for large-scale industrial applications.. Since the heat treatment method is carried out under high temperature conditions, the energy consumption is high, and the organic solvent remaining in the electrode will have a harmful gas, and special devices are purified.

. The mechanical separation method is to use the physical characteristics of the components, such as differential differences such as particle size, magnetic properties, density, etc. to achieve separation of each component.

. Since the lithium ion battery is complex, the chemical component composition comprises a plurality of metals, organic matter, inorganic substances, and mechanical separation methods difficult to achieve high separation of each component, so recovering product impurity content, low purity. The solvent method is to dissolve the binder using an organic solvent having the same polarity of the same polarity using a similar phase soluble.

. Figure 1. Solvent method treatment of retired battery process, compared, common solvent is N-methylpyrrolidone, can promote the dissolution of the binder in retired battery recovery.

Further, the activation of the active material obtained by the solvent method is high, so that the assembled battery performance is also excellent, and the solvent method is small in destructive, simplifies the separation process, but the generally used organic solvent is expensive, the toxicity is large, to the human body Harmful. The alkali solvent is important to selectively dissolve the aluminum foil using a strong base, while Li, Ni, Co and Mn viable metal in the electrode material are substantially unsoluble, thereby achieving separation of aluminum foil and active substance..

High concentrations of alkali in alkali is harmful to the environment and human body, and there are more bonding agents and conductive carbon black residues, affecting subsequent ratio metal leaching. The two immersed valvily metal is dissolved in the retired tri-ion battery electrode active material such that Li, Co, Ni, Mn valuable metal is highly efficiently immersed in solution, which is the core of wet recovery technology..

At present, an important method for the price of metal leaching for ternary materials is acid immersion method and biological immersion method.. Add an appropriate amount of reducing agent in the leaching liquid, which can effectively improve the immersion efficiency of the price.

An important use of reducing agents (H2O2, NaHSO3, glucose, etc.) is to reduce CO and MN of high-priced in solid phase into CO2 + and Mn2 +, improve CO and Mn’s immersion rate..

The acid immersion method can transfer metal ions of most solid powder to the acid solution, and can be effectively separated from residual components such as moisture carbon, binder, etc., for subsequent separation and purification supply of raw materials. Acid immersion method is divided into inorganic acid and organic acid.

The inorganic acid can dissociate hydrogen ions, exhibiting strong acidity, with strong dip effects on Li, CO, Mn, and N.. The immersion of the inorganic acid is important in hydrochloric acid, sulfuric acid, nitric acid, etc.

as a leaching agent, and then detested acid impant and residue.. In the inorganic acid leaching system, there is more than the solvent system as a leaching agent, H2O2 as a reducing agent.

. The source of inorganic acid is wide, the price is relatively inexpensive, but it is prone to CL2, SO3, NOx acid gases and waste liquids, resulting in potential threats to the health of the environment and people..

And the strong acid of the inorganic acid, the strong corrosion resistance is higher to the production equipment, and the recovery cost has been added to some extent.. Compared with the organic acid to extract the price of metal and inorganic acid, the equipment instrument used is weak, and the waste liquid in the process is easy to biodegradation, which is low in environmental pollution, suitable for recycling, and exhibits viable metals.

Excellent dip ability. In recent years, the technology of organic acids such as formic acid, tartaric acid, citric acid, and malic acid is favored by researchers..

In numerous organic acids, citric acid can be dissolved into H +, Hcit2-, H2cit- and Cit3 in an aqueous solution, which is advantageous for metal immersion.. Apple acid is an environmentally friendly dual organic weak acid, contains 1 hydroxyl group, 2 carboxyl groups, and transition metal binding to form a complex, since itself self-strap hydroxyl group, has a certain reduction, can promote forward in the dip reaction Reaction use.

In addition to different types of acid leaching agents and reducing agents have an important impact on metal, the concentration of the leaching agent, the amount of reducing agent, the liquid solid ratio, the time, and the temperature of the leaching are also important factors affecting metal leaching.. Biological immersing is the use of microbial bacteria to realize metal dip and dissolution.

Biological dip has the advantages of small consumption, high metal dissolution rate, environmentally friendly, moderate operation conditions, etc., gradually applied to the recycling of viable metals. Biological immersing is the potential technology of the fuel-retired battery price metal, but in a higher metal solubility solution, the flora is easily inactivated, and the immersion efficiency is affected, so the biometric method is only suitable for low-soluble metals.

Solution. In addition, the cycle of bioformats should be cultivated, demanding environmental requirements, limiting their industrial applications..

Therefore, further improve the culture velocity of strains, adsorbing metal ion speed, etc., improve the leaching rate of metal ions..

The three-point extraction of the price is the separation extraction of the valuable metal from the leaching liquid. It is currently an important extraction method and a precipitation method..

The extraction method is to select a mixture of one or several organic solvents as an extractant, and the target metal ion forms a complex complex, and then transfer metal ions of the complex complex to another organic solvent, and then realize Different metal ion separation and purification. The extraction method is low, the equipment is simple, the separation effect is good, the recovered metal is high, but the extractant is mostly toxic organic solvent, the cost is higher, the separation process is complex. Regarding the system containing Li, Ni, Co, Mn, the usual extractant is often used with trimethylate, diphosphate, monoethylphosphinate mono-2-ethyl ester, etc.

. The precipitation method is to add a suitable precipitant to the leaching liquid such that metal ions and precipitates form a compound that is difficult to dissolve, thereby achieving metal separation..

Figure 2. Retired ternary battery precipitation separation recovery flow chart passed through acid leaching nickel-manganese electrode material, the precipitation method can realize the purification and precipitation of metal ions. The step of the precipitation method is simple, the cost is low, the flow is short, the metal ion recovery is high, but Ni, Co, Mn is the transition metal, the chemical properties are similar, and the coprecipitation is low, resulting in low purity.

Therefore, in the precipitation process, it is important to select a suitable precipitant and control precipitation conditions.

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