Lithium iron phosphate batteries have good cycle performance, low price, good safety, and the potential for fast charging. Therefore, with the rapid development of the domestic electric vehicle industry, the demand for lithium-ion batteries is also increasing rapidly. Currently, electric buses and other vehicles with high safety requirements mainly use lithium iron phosphate batteries.
Lead-acid batteries are widely used in transportation, communication, and backup power. They are inexpensive, highly reliable, and easy to maintain, making them the world's most produced and widely used type of battery. However, they also have the greatest environmental impact. Their application is limited due to the harmful effects of lead on human health, the environmental pollution caused by sulfuric acid, and its corrosive properties on equipment.
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.
In my country, recycled waste rechargeable batteries must be manually sorted to separate nickel-cadmium, nickel-metal hydride, and lithium-ion batteries. They are then placed in sturdy plastic containers, sealed, and stored in specialized warehouses protected from rain, sun, fire, and theft. It is estimated that the collected waste batteries will need to be stored for a certain period before processing. The recycling of disposable dry-cell batteries will only be profitable once a certain volume is reached. The current disposal method involves centralized and harmless landfilling at sanitary landfills, with recycling to be carried out once the technology is mature.
It is understood that, based on battery lifespan and the rate of electronic device upgrades, the number of discarded rechargeable batteries generated in Shenzhen each year is staggering, reaching 50 to 100 tons per year. The main source of pollution from discarded batteries is the rechargeable batteries themselves, which contain lead that can damage the circulatory, digestive, and nervous systems, while cadmium can cause serious conditions such as kidney damage and osteomalacia.
Due to the potential heavy metal and organic pollution from waste batteries, waste battery pollution has attracted widespread attention from the public, media, and environmental management departments in recent years. Developed countries have a very positive attitude towards waste battery recycling.
Japan: Nomura Industrial Corporation in Hokkaido collects 13,000 tons of waste batteries annually from across Japan, accounting for 20% of the country's total waste batteries. 93% of these batteries are collected through private environmental organizations, and 7% through manufacturers. Previously, the primary focus was on recovering the mercury, but since domestically produced batteries in Japan no longer contain mercury, the focus has shifted to recovering the battery casing and the black components, and then developing and manufacturing secondary products. One such product can be used in television picture tubes.
Germany requires consumers to take all types of batteries, including dry cell batteries and button batteries, to stores or recycling centers for recycling. Stores and recycling centers must accept used batteries unconditionally and forward them to manufacturers for processing. Recycling centers and manufacturers generally only recycle batteries containing toxic chemicals such as cadmium and mercury, while 90% of ordinary zinc-carbon batteries and aluminum-magnesium batteries are disposed of as household waste in landfills or incinerators.
Switzerland: A factory uses a heat treatment method to process used batteries. The batteries are ground up and then heated in a furnace to extract the volatilized mercury and zinc, which are precious metals. Iron and manganese are fused together to form ferromanganese alloy, needed for steelmaking. The factory can process 2,000 tons of waste batteries annually, yielding 780 tons of ferromanganese alloy, 400 tons of zinc alloy, and 3 tons of mercury.
The United States has the most detailed and comprehensive legislation on waste battery environmental management. It has not only established a comprehensive waste battery recycling system, but also built many waste battery processing plants. At the same time, it has consistently carried out public education and awareness campaigns to encourage the public to consciously support and cooperate with waste battery recycling efforts.
