Recycling old batteries is a crucial method for environmental protection and resource conservation. Therefore, it has become increasingly important to recycle old batteries in a reasonable manner and utilize them to produce recycled resources.

Battery recycling is essential; if discarded batteries are not properly disposed of, they can contaminate our water sources, erode the crops and land upon which we depend, and threaten our living environment. Therefore, it is necessary to recycle and reuse used batteries, both to prevent environmental pollution and to reuse the valuable components within them, conserving resources.

Battery Recycling: Why Recycle Used Batteries

Waste batteries discarded in the environment can affect the pH levels of soil and water systems, causing them to become either acidic or alkaline. Heavy metals like Hg and Cd, when absorbed by organisms, enter the human food chain through various routes, accumulating in the human body and potentially causing deformities or mutations. A single button battery can contaminate 600,000 liters of water, equivalent to a person's lifetime water intake. A single battery left in the ground can render one square meter of land unusable. Among the five substances posing the greatest threat to the natural environment, batteries contain three of them.

Battery recycling, the process of recycling and handling spent batteries generally includes the following points:

1. Category: The recycled spent batteries can be crushed, with the zinc casing and battery bottom iron removed, and the copper caps and graphite rods extracted. The remaining black material consists of a mixture of manganese dioxide and the battery core. After separately collecting these materials and processing them, we can obtain some useful substances. The graphite rods, after being washed with water and dried, can be reused as an electrode.

2. Zinc granules production: After cleaning the stripped zinc shells, place them in an iron pot and heat them, then maintain the temperature for 2 hours. Remove the top layer of scum, pour out the mixture for cooling, and then drip it onto an iron plate. Wait until it solidifies to obtain zinc granules.

3. Copper Sheet Recycling: We can flatten the copper caps, wash them with hot water, then boil them in a solution of 10% sulfuric acid for 30 minutes to remove the surface oxidation. After removing and washing, dry them to obtain copper sheets.

4. Recycling: We place the black substance in the tank, add 60°C warm water, and stir for an hour to dissolve it all. Then, let it settle, filter, and wash the residue twice with water to collect the mother liquor.

5. Manganese Dioxide Recovery: We wash the filtered residue with water three times, filter it, then dry it in a pot to remove a bit of carbon and other substances. Afterward, we immerse it in water and stir for 30 minutes thoroughly. Filter again, and finally, dry the filtrate at 100-110°C. This process yields manganese dioxide.

Battery Recycling: What are the methods for recycling and utilizing waste batteries?

1. The method of heat treatment involves crushing old batteries and sending them to the furnace for heating. At this point, the emitted Hg can be extracted. When the temperature is very high, zinc also evaporates, which is also a precious metal. Iron and manganese melt together to form the manganese iron alloy required for steelmaking.

2. Wet Processing: In this wet processing facility, all types of batteries, except for lead-acid batteries, are dissolved in sulfuric acid. Various metals are then extracted from the solution using ion exchange resins. The raw materials obtained through this method are purer than those from thermal processing, hence they command a higher market price. Moreover, 95% of the substances contained in the batteries can be extracted. Wet processing eliminates the sorting step (since sorting is a manual operation that adds to costs).

3. Vacuum Heat Treatment Method: First, nickel-cadmium batteries must be sorted from the waste batteries. The waste batteries are heated in a vacuum, where Hg evaporates rapidly, allowing for recovery. The remaining material is then crushed and the metal iron is extracted using a magnet. Nickel and manganese are further extracted from the remaining powder. The cost of processing one ton of waste batteries is less than 1,500 marks (now approximately 6,345.18 yuan)!!

Battery Recycling, Key Features of Lithium-ion Batteries:

1. High open-circuit voltage: The single battery cell voltage typically reaches 3.6V, which is three times that of a standard nickel-hydride or nickel-cadmium battery.

2. High Energy Density: Taking the UR18650 battery as an example, its mass energy density and volume energy density can reach 125Wh/kg and 300Wh/cm³, respectively.

3. High output power, suitable for high current charging and discharging.

4. Excellent cyclic performance, no memory effect.

5. Self-discharge rate low: At room temperature, the self-discharge rate is less than 12%, with nickel-cadmium batteries (about 25%/month) and nickel-metal hydride batteries (about 15%/month). Due to the formation of a solid electrolyte interface (SEI) film on the carbon negative surface during the charging and discharging process, this film allows ions to pass through but not electrons, effectively preventing the self-discharge process.

6. Recharge/Discharge: The Coulomb efficiency can reach after cycles.

7. Wide operating temperature range: -25°C to +45°C; the working temperature range can be expanded to -40°C to +70°C if the thermal stability of the positive material and electrolyte is improved.

8. Environmentally Friendly Chemical Energy: Lithium-ion batteries are free of pollutants and represent an extremely eco-friendly chemical energy storage device.

9. Long cycle life: With 80% discharge depth, the cycle life exceeds 1200 cycles; with a shallower discharge depth, the cycles can reach over 5,000.

10. Excellent processing flexibility, capable of producing batteries in various shapes, such as cylindrical and soft-pack. Consequently, lithium-ion secondary batteries offer significantly superior advantages compared to traditional secondary batteries.