Dry recycling technology for spent lithium-ion batteries, also known as mechanical-physical methods, is a process for recovering materials or valuable metals without the use of solvents. Below, we will provide a detailed introduction to dry recycling technology.
Definition of Dry Recycling Technology
Without Solvents: Dry recycling refers to the method of directly recovering materials or valuable metals without the use of solvents or other media. It primarily involves physical separation techniques and high-temperature pyrolysis to coarsely sort and classify the crushed battery materials, or to remove organics through high-temperature decomposition to facilitate further element recovery.
No Additional Chemical Reactions: Dry recycling does not involve additional chemical reactions. The process is relatively short, and the targeted recovery is not as specific, making it suitable for the initial stages of metal separation and recovery.
Methods of Dry Recycling for Lithium-Ion Batteries
(1) Mechanical Separation: Mechanical separation utilizes the differences in physical properties such as density and magnetism of the battery components. The process involves crushing and sieving to coarsely sort and classify the battery materials, achieving the preliminary separation and recovery of different valuable metals. Due to the unique structure of lithium-ion batteries, where the active materials and current collectors are tightly bonded, it is challenging to fully separate the metals. During sieving and magnetic separation, there is often a loss due to mechanical entrapment, making complete separation difficult.
(2) High-Temperature Pyrolysis: High-temperature pyrolysis primarily involves the removal of binders through high-temperature incineration, allowing the materials to separate. Additionally, the metals in the battery undergo oxidation, reduction, and decomposition during the high-temperature process, forming gaseous volatiles that can be collected through condensation. Although this method is simple and produces a single product, it is energy-intensive and is more suitable for the pre-treatment stage.
These technologies collectively form the dry recycling methods for spent lithium-ion batteries. There are multiple ways to process spent lithium-ion batteries, and common methods include hydrometallurgy and pyrometallurgy, which will be discussed in detail later.
