Lithium-ion battery recycling market
Currently, my country is a major global producer and consumer of batteries, consuming 8 billion batteries annually. However, the common methods for disposing of used batteries are landfilling, incineration, and composting with household waste, making recycling a massive and urgent task. If waste lithium-ion batteries are not systematically processed and recycled, they will severely waste resources, pollute the environment, and harm human health.
The huge market demand for lithium-ion batteries will lead to a large number of waste batteries in the future. How to deal with these waste lithium-ion batteries in order to reduce their environmental impact is an urgent problem to be solved. On the other hand, in order to meet the huge market demand, manufacturers need to produce a large number of lithium-ion batteries to supply the market.
Waste lithium-ion batteries contain significant amounts of metals such as cobalt (Co), lithium (Li), nickel (Ni), manganese (Mn), copper (Cu), and iron (Fe), including several rare metals. Cobalt, in particular, is a scarce strategic metal in my country, which relies heavily on imports to meet its growing demand. The metal content in some waste lithium-ion batteries is higher than that in natural ores; therefore, given the increasing scarcity of production resources, recycling waste batteries has considerable economic value.
Lithium-ion battery recycling technology
The recycling methods for lithium-ion batteries can be mainly divided into three categories: dry recycling, wet recycling, and biological recycling.
1. Dry recycling
Dry recycling refers to the direct recovery of materials or valuable metals without the use of solutions or other media. Important methods used include physical sorting and high-temperature pyrolysis.
2. Wet recycling
The wet recycling process involves crushing and dissolving waste batteries, then using appropriate chemical reagents to selectively separate metal elements from the leaching solution, producing high-grade cobalt metal or lithium carbonate, which are then directly recycled. Wet recycling is well-suited for recovering waste lithium-ion batteries with relatively simple chemical compositions. Its equipment investment costs are relatively low, making it suitable for small to medium-scale waste lithium-ion battery recycling. Therefore, this method is currently widely used.
3. Biological recycling
Mishra et al. used inorganic acids and *Acidithiobacillus ferrooxidans* to leach metals from spent lithium-ion batteries, utilizing sulfur (S) and ferrous ions (Fe2+) to generate metabolic products such as H2SO4 and Fe3+ in the leaching medium. These metabolites help dissolve the metals in the spent batteries. Bioleaching is a low-cost, high-efficiency, low-pollution, low-consumption, and relatively environmentally friendly method, and the microorganisms can be reused. However, the difficulty in cultivating highly efficient microorganisms, the long processing cycle, and the control of leaching conditions are several major challenges for this method.
4. Combined recycling methods
Each recycling process for waste lithium-ion batteries has its own advantages and disadvantages. Currently, there is research on recycling methods that combine and optimize multiple processes in order to give full play to the advantages of various recycling methods and maximize economic benefits.
Waste lithium-ion battery recycling technology
*Biometallurgical method: Utilizing the metabolism of microorganisms to selectively leach elements such as cobalt and lithium.
*Direct electrode repair technology: This technology involves breaking down the binder to separate the electrode material for recycling.
* Leachate synthesis of electrode materials: The leachate directly participates in the chemical reaction to generate lithium cobalt oxide electrode materials.
