The global surge in renewable energy and electric vehicles has been underpinned by a key technology: lithium-ion batteries. Yet, as these batteries reach their end-of-life (EoL), they present a significant challenge. Their disposal not only represents an environmental hazard, but it's also a waste of valuable materials. The solution lies in embracing a circular economy that aims to reintroduce spent materials back into the manufacturing cycle.
The circular economy of lithium-ion batteries are conceptualized through two flows: a closed-loop system and an open-loop system.
In a closed-loop system, the lifecycle begins with the extraction of virgin raw materials such as lithium, cobalt, nickel, manganese, and aluminum. Once extracted and processed, these materials are transported to battery manufacturing facilities. Here, they are utilized in the production of lithium-ion batteries through several stages including cathode and anode preparation, cell assembly, formation, and aging.
The produced batteries are then integrated into various devices, such as electric vehicles or renewable energy storage systems. Once a battery's capacity falls below a certain threshold, usually about 80% of its initial capacity, it's considered at its EoL. Rather than being disposed of, these EoL batteries are collected and sent to recycling facilities.
At these facilities, the valuable metals within the batteries are extracted using techniques such as pyrometallurgy, hydrometallurgy, and the less mature, bio-metallurgy. The aim is to recover as many valuable materials as possible. After extraction, the metals are refined to ensure they are free from impurities and meet the necessary quality standards for battery production.
Finally, the refined materials are reintroduced into the battery production cycle, creating a closed-loop system. This reduces waste, optimizes resource utilization, and mitigates environmental impact.
The second flow, the open-loop system, follows a similar trajectory but differs at the point of metal recovery. In this system, materials extracted from EoL batteries that do not meet the quality requirements for battery production are redirected.
After undergoing extraction and refinement, these materials may not be suitable for battery production, but they are still valuable. They, along with other pre-treated materials, are supplied to other industries where they are used in the production of various goods.
In essence, both the closed and open-loop systems offer innovative approaches to managing EoL lithium-ion batteries. By focusing on resource recovery and reintroduction, these systems divert valuable materials from landfills, reducing environmental impact and promoting sustainable production.