Everyone knows that disposing of used batteries is quite troublesome, and littering them causes significant environmental damage. In the treatment of used lithium-ion and lead-acid batteries, recycling and reuse are one aspect, but it's also crucial to eliminate this pollution at its source. Only with increased public awareness and the establishment of a comprehensive and effective recycling network and system will the pollution problem caused by used batteries gradually be resolved.
What are the hazards of discarded lithium-ion batteries?
Lithium-ion batteries pose no harm to humans or the environment during normal use. However, improper disposal of discarded lithium-ion batteries can harm the environment and then affect surrounding organisms and humans through environmental transmission. This is primarily because chemicals such as lithium hexafluorophosphate and polypropylene glycol contained in lithium-ion batteries can cause organic pollution. Additionally, heavy metals such as cobalt contained in these batteries can also harm the environment.
In the treatment of waste lithium-ion batteries, the first step is to pre-treat them, including discharging, dismantling, crushing, and sorting. The plastic and iron shells after dismantling can be recycled. Then, the electrode materials are subjected to alkaline leaching, acid leaching, and other processes before extraction.
The electrolytes and their conversion products from used lithium-ion batteries, such as LiPF6, LiAsF6, LiCF3SO3, HF, P2O1, etc., as well as the solvents and their decomposition and hydrolysis products, such as DME, methanol, formic acid, etc., are all toxic and harmful substances. Used lithium-ion batteries should be sent to qualified facilities for unified treatment and should not be discarded at will.
Lithium-ion batteries contain various toxic substances, exhibiting strong corrosiveness and polluting properties. Furthermore, waste lithium-ion battery electrolytes contain highly toxic, flammable, explosive, and corrosive electrolytes and organic solvents. Improper disposal or leakage will pollute and damage the atmosphere, water, and soil. Moreover, electrolyte leaks and excessively high temperatures can cause battery explosions and fires, directly threatening people's lives and property.
In addition, a series of pollutants are generated during the crushing, sorting, and high-temperature pyrolysis pretreatment of waste lithium-ion batteries, such as electrolyte decomposition, plastic film pyrolysis, crushing dust, and waste residue. These pollutants not only cause serious pollution to the atmosphere and water bodies but also have a severe corrosive effect on equipment. At the same time, the various acid and alkali leaching agents, extractants, and active additives added during the process not only increase the cost of the recycling process, causing resource waste and increased energy consumption, but also generate a large amount of wastewater, waste gas, waste residue, and waste additives, which cause secondary pollution.
The dangers of used batteries
The main hazards of used batteries lie in the small amounts of heavy metals they contain, such as lead, mercury, and cadmium. These toxic substances enter the human body through various routes, accumulate over time, and are difficult to eliminate, damaging the nervous system, hematopoietic function, and bones, and may even cause cancer.
1. Mercury (Hg) has significant neurotoxicity and also has adverse effects on the endocrine and immune systems, causing rapid pulse, muscle tremors, and oral and digestive system lesions;
2. Cadmium (Cd) can enter the human body through various pathways, accumulate over a long period and is difficult to eliminate, damaging the nervous system, hematopoietic function and bones, and may even cause cancer;
3. Lead (Pb) can cause neurasthenia, numbness in the hands and feet, indigestion, abdominal cramps, blood poisoning and other diseases; manganese can harm the nervous system.
How harmful are used lead-acid batteries?
Hazardous substances produced in lead-acid battery manufacturing include lead, sulfuric acid, carbon black, sulfur, and asphalt. Lead and sulfuric acid pose the most frequent exposure to workers, and these two substances are particularly harmful. my country has already included lead poisoning, carbon black pneumoconiosis, and dental erosion in its list of legally recognized occupational diseases.
1. Routes of lead ingress and hazards
The primary route of entry for lead and its compounds is through the respiratory tract, followed by the digestive tract; intact skin cannot absorb them.
2. Routes of entry and hazards of sulfuric acid
Sulfuric acid is primarily introduced through the respiratory tract, causing damage to the teeth and upper respiratory tract of workers. Currently, dental erosion is listed as a legally recognized occupational disease. While respiratory allergic reactions are not listed, they should still be considered.
