What kind of pollution will be caused by the production and recycling of lithium batteries?

Boko Raw Materials reminds you:

The Shenma stuff should not be there if it is not polluted. If it appears, it should be in a certain amount. If it is excessive, there should be no heavy metals in the river. , the presence of heavy metals is called pollution, but if there are no heavy metals in mines, it won’t be the same. There is a small amount of phosphorus in the river. Now excessive phosphorus has caused eutrophication, which is also pollution. In short, leaving things lying around is pollution. Whatever it is. Of course, you are welcome to contaminate my home with money, gold, silver, platinum, gems, diamonds, securities, etc.

It is not very meaningful to discuss the pollution problem of lithium batteries because they contain less toxic substances. It mainly depends on the management and control of the production company. If the production of chemical pesticides is well controlled, it is also very good. On the contrary, if the company that produces lithium batteries does not control it, it cannot be ignored.

Look at the pollution problem of lithium batteries from the toxicity of each component to the human body. Its composition is as follows:

1. Positive and negative current collectors. Generally, aluminum foil is used for the positive electrode and copper foil is used for the negative electrode. Some nickel strips may also be welded for connection and conductivity. These are basically non-toxic. Some waste lithium battery recycling units that have emerged now make money by recycling these and steel and aluminum casings. Label: recyclable, pollution-free.

2. The negative electrode is usually graphite, and a few may be lithium titanate or silicon-based materials. Of course, tin-based negative electrodes are also available, but they are so damn high-end that no one uses them now. Graphite is divided into natural graphite and artificial graphite. Natural graphite comes from graphite ore, and then undergoes some processing. The mining of natural graphite causes serious pollution, mainly causing damage to the respiratory tract. You can search for it; artificial graphite, It is made of high-temperature graphitization of polymers such as petroleum coke or asphalt, and is basically pollution-free. There are some recycling methods for graphite flotation in lithium batteries, but I don’t know how they are currently used. It can definitely be recycled. The production process of lithium titanate is unclear. Silicon-based negative electrodes are basically pollution-free. Evaluate according to the graphite with the largest dosage. Label: Moderately contaminated, recycling status unknown.

3. Positive electrode: The current positive electrodes include lithium iron phosphate, lithium manganate, ternary materials, lithium cobalt oxide, and lithium nickel cobalt aluminate. Lithium iron phosphate is generally used as car batteries or energy storage batteries and is non-toxic. Lithium manganate, electric bicycle battery, non-toxic. Ternary material: lithium nickel cobalt manganate, widely used in electric bicycles, electronic products, model aircraft, etc. Cobalt element is toxic. Lithium cobalt oxide, used in digital products, mobile phones, pads, etc., is moderately toxic. Lithium nickel cobalt aluminate: unknown, guessed to be the same as lithium nickel cobalt manganate.

4. The electrolyte is composed of organic solvents and lithium salts. Organic solvents generally include pc, ec, dec, dmc, dme, etc., among which dmc is microscopic and the others are non-toxic. The lithium salt is lithium hexafluorophosphate (the most commonly used, but there are also other lithium salts). When exposed to water, it hydrolyzes to form hf, which is toxic.

5. There are several categories of shells: aluminum shells, steel shells, plastic shells, and aluminum-plastic films. The aluminum shell and steel shell are non-toxic. Plastic shells and aluminum-plastic films are white pollution.

6. Separator, usually a microporous film of polyolefin, pp, pe, white pollution.

7. Binders, currently generally include styrene-butadiene rubber SBR, polyvinylidene fluoride PVDF, and some acrylic binders. Just think of these as white pollution.

In addition, the substances used in the lithium battery processing process are mainly NMP (slightly toxic), which are used as solvents for the positive and negative electrodes. They evaporate during the manufacturing process, and companies need to control their emissions and recycle them.

In my opinion, there are currently three main categories of pollution problems in lithium batteries:

First, pollution caused by cleaning equipment for positive and negative electrode pulping and coating equipment during the production process. These two include positive and negative electrode materials, NMP, glue and other substances. Some companies have poor control (malicious speculation and do not want to control), resulting in the leakage of toxic wastewater.

First point 1. Cleaning the supplies for injecting electrolyte during the production process may cause water containing electrolyte to flow into the sewer.

Under normal circumstances, technical developers are likely to discharge water directly into the sewer.

Second, nmp recycling is not complete.

Third, it is true that very few lithium batteries circulating in the market are recycled. First, lithium batteries themselves pollute little, and people don’t pay enough attention to them. Second, the income from recycling lithium batteries is low. As a result, lithium batteries now do not have large-scale recycling applications like lead-acid batteries, but are more like nickel-metal hydride and other batteries, with only a few slogans such as "Don't throw away batteries casually".

I have been writing for more than 40 minutes today, and I still have to work overtime, so let’s just do it.