Recycling Process

Lithium-ion batteries are a solution for energy storage in electronic devices and electric vehicles, leading to increased demand for raw materials. Developing sustainable recycling processes is crucial to mitigate the impact of battery manufacturers.

The value and carbon footprint of batteries are greatly influenced by the raw materials used in their production. Geopolitical risks in the supply chain of these materials threaten the production capacity and economic stability of local manufacturers.

E-Bus Parked. Starofmystore.com (2023)

In particular, lithium-ion batteries, widely used in electric vehicles, rely on specific minerals such as lithium, cobalt, nickel, and rare earth elements. These minerals are geographically concentrated, posing geopolitical risks. Any disruption in the supply chain, such as political instability, trade disputes, or export restrictions, can significantly affect the availability and cost of these materials.

Course Mascot (2023)

Consequently, these geopolitical risks associated with the raw material supply chain pose a threat to the overall stability and production capacity of the battery industry. Managing these risks becomes crucial to ensure a reliable and sustainable battery supply for various applications.

To address these challenges, some companies are commercializing new technologies for battery recycling. The initial step in the recycling process involves the collection, unloading, and dismantling of spent batteries, where optimizing storage logistics, transportation costs, and energy consumption are important considerations.

Recycling Processes

Battery recycling is a complex and selective process that demands high recovery rates for scarce materials, while effectively managing hazardous components. With batteries varying in size, shape, and chemical compositions, recyclers face increased pressure to optimize their processes, ensuring flexibility to adapt and maintain financial sustainability.

Furthermore, there are additional factors that add to the challenges for battery recyclers. These include growing battery consumption, diverse battery chemistries, resource recovery and environmental regulations, and technological advancements.

The combination of these factors places greater pressure on recyclers, necessitating process optimization, flexibility, and financial sustainability. Recyclers must meet the rising demand for battery recycling, adhere to regulations, and effectively navigate the evolving landscape of technology and battery chemistries. In the recycling process, the battery goes through a series of steps, transforming it into simpler components. Depending on the battery’s chemistry and chosen process, recycling may require several steps, including physical, mechanical and chemical transformations.

These recycling processes can be classified as the following.

• Pyrometallurgical Recycling.
• Hydrometallurgical Recycling.
• Mechanical/Physical Recycling.

Depending on the steps to be followed, battery recycling systems can return some of the raw materials recovered from the batteries, return materials in a form that eliminates steps in the battery supply chain, and return materials in a form ready for immediate electrode and electrolyte reuse. Generally, the battery supply chain involves stages like raw material extraction, refining, component manufacturing, assembly, and distribution. By streamlining the process, battery recycling eliminates the need for extensive processing or acquiring new raw materials, making more efficient use of recovered materials.

Types of recycling. PEM Motion (2023)

Pyrometallurgical Recycling

Pyrometallurgical recycling systems use high-temperature furnaces in which the batteries are introduced. In the case of large batteries (such as those used in electric vehicles), it is necessary to disassemble them from the pack beforehand in some cases. The chemical components (e.g. copper, cobalt, nickel, iron) are reduced to molten metals that are collected as alloys at the end of the process. The solid alloy is usually sent to metal refineries for further processing and recycling. Furnace slag is produced, consisting of ash from the burned components and containing mainly lithium, aluminum, silicon, calcium, and some iron compounds. This pyrometallurgical process is considered a mature technology for battery recycling as one of its advantages is to recycle all the battery chemicals simultaneously.

The pyrometallurgical process used in battery recycling has shown impressive recovery rates for specific materials. On average, it can recover and recycle approximately 80% to 95% of the initial materials found in batteries.

It’s worth noting that the exact recovery rates can vary depending on factors like the battery type, material composition, and the efficiency of the recycling facility. Some materials may require additional refining or processing steps before reusing, and certain components may be more challenging to recover effectively.

Overall, the pyrometallurgical process has proven to be a mature and effective technology for battery recycling. It plays a crucial role in resource conservation by significantly reducing the reliance on new raw materials and promoting a circular economy approach.

E-Bus in a bus stop in Brazil. Experts Mission Beio Horizonte Brazil (2019)

Hydrometallurgical Recycling

Hydrometallurgy uses acids to dissolve the metal components of the batteries in a process known as leaching. The batteries are disassembled to facilitate dissolution, and the cells are fragmented by crushing. Once the metals are put into solution, several steps of solvent extraction, chemical precipitation and/or electrolysis may be necessary to separate the constituent elements. The main drawback of hydrometallurgical processes is the difficulty of treating different chemistries and battery types. Each recycling sequence must be optimized for a given battery chemistry to ensure high recovery and favourable profitability.

The hydrometallurgical process utilized in battery recycling has demonstrated significant recovery rates for specific materials. On average, it can recover and recycle approximately 70% to 90% of the initial materials found in batteries.

Just like the pyrometallurgical process, the precise recovery rates can vary depending on factors like battery type, material composition, and the efficiency of the recycling facility. The hydrometallurgical process involves using chemical solutions to dissolve and separate different battery components, enabling the retrieval of valuable metals and other materials.

It is important to acknowledge that not all materials can be fully recycled and reused through the hydrometallurgical process, as some components may present limitations or necessitate additional processing for reuse. Nonetheless, hydrometallurgical recycling remains a significant and effective approach for recovering valuable materials from batteries while reducing the demand for new resources.

Mechanical/Physical Recycling

It consists of manual and/or automated disassembly of the battery, recovering critical components in their original state (e.g. electrodes, wiring, casing). Some recovered parts can be used directly to manufacture new batteries, while other components (e.g., wiring) can be recycled using the usual pyro- or hydrometallurgical systems. The mechanical/physical process is still under development, and its effectiveness has yet to be proven, but it provides components that can be immediately reused in new batteries. This process is used only in pilot projects since everything that can be recovered from the batteries could become obsolete.

The components recovered from batteries may become obsolete or incompatible with future advancements in battery technology. As battery composition, structure, and specifications change over time, some of the recovered components may lose their relevance or suitability for use in newer battery systems.

While the potential for obsolescence exists, it is not certain. The effectiveness and applicability of recovered components depend on ongoing developments and changes in battery technology. This emphasizes the importance of continuous research and adaptation to ensure that recycling processes align with the evolving requirements of emerging battery technologies.

E-Bus with garlands in India. Karntankacom (2019)

The mechanical/physical process is currently undergoing refinement and optimization through ongoing research and development efforts. The primary objective is to enhance the recovery and reusability of materials to their maximum potential. The effectiveness of this process hinges on advancements in technology and the capability to extract valuable components with greater efficiency.

Researchers and industry professionals are actively working towards improving the mechanical/physical process, exploring innovative techniques and technologies to enhance material recovery rates and promote greater circularity in battery recycling. Through continuous advancements and optimization, the mechanical/physical process is anticipated to become increasingly effective in recovering and reusing materials from batteries.

Conclusion

With these processes identified as necessary for the recycling of batteries, two mature and the other in the pilot stage, it was possible to recognize that all the components obtained could be introduced directly into the production of new batteries, thus reducing the cost and complexity of their manufacture.

It is essential to recognize that the mechanical/physical recycling process outperforms pyro and hydro in terms of materials recovered. Although, this process is very new and only a few recyclers use it.

Therefore, it’s crucial to have proper recycling facilities and processes in place to ensure efficient and environmentally friendly battery recycling.

Let’s take in a following step a look at the materials that are recovered in the recycling process, shall we?

References

• Neumann, et al.(2022) Wiley Online Library. Retrieved from: Link
• Transport & Environment (2019) Batteries on wheels: the role of battery electric cars in the EU power system and beyond Retrieved from: Link