Battery Recycling Through Extraction of Metals from Spent Lithium-ion Batteries
Automotive original equipment manufacturers (OEMs) are introducing more plug-in hybrid and electric vehicles (EVs). At the same time, they are faced with tougher recycling mandates which is leading to the development of reverse logistics networks and efficient recycling chains to process growing volumes of spent EV batteries. Tomorrow’s demand for battery metals is unlikely to be met by primary mining alone, and traditional recycling fails to yield the high-grade metals required for EV batteries. For these reasons, the automotive industry is looking for a new solution, a circular solution. Solvay’s portfolio of metal-specific extractants can be used to assemble solvent extraction circuits in a cascade and recover all valuable metals from spent lithium-ion batteries. Our reagents, backed by our technical capabilities and experienced teams, enable the recovery of critical metals from various lithium-ion battery sources, such as those powering electric vehicles, e-bikes, power tools, electronic devices, or stationary storage stations.
The Recycling Process
The process for the recycling of lithium-ion batteries can be divided into three main steps: (1) Pre-treatment (2) Material/Metal refining & extraction (3) Transformation & Chemical production. For each step, a variety of process options exist and typically a combination of technologies is used. During pre-treatment, batteries are conditioned into a form in which they are accessible for further material & metal recovery. Discharging, dismantling, mechanical pre-treatment, thermal pre-treatment, and/or smelting (often a combination) are techniques currently used. The material that comes out of the pre-treatment (e.g. black mass, alloy) needs further processing to be reintroduced into the battery value chain. This happens in the subsequent step where the streams are metallurgically refined typically via hydrometallurgical unit processes; metals are extracted to solutions (acids), separated from each other, and impurities are removed. Finally, the valuable battery metals are recovered from the purified hydrometallurgical solutions into products (e.g. Co salts, Ni salts, Li salts). These can be further transformed into new precursor and battery materials.
Solvay’s portfolio of metal-specific extractants can be used to assemble solvent extraction circuits in a cascade and recover all valuable metals from spent lithium-ion batteries.
Potential solvent extraction flow diagram for recovery of value metals from spent lithium-ion battery
Capturing Value From Spent Batteries
After the initial operations of mechanical and direct recycling to discard external battery casing and reclaim cathode materials, the battery recycling process continues with hydrometallurgy or pyrometallurgy to recover critical metals such as Lithium, Cobalt, Manganese, Copper, and Nickel. In collaboration with partner organizations in a circular economy consortium, Solvay's mining solutions are able to support the more environmentally friendly recycling technology of hydrometallurgy to optimize metal recovery processes and value chain solutions, ensure security of supply and reduce the carbon footprint commonly associated with EV lithium-ion battery recycling processes.
CO2 Savings Related to the Transition to Electric Vehicles
Life Cycle Assessment (LCA) is a methodology used to evaluate the environmental impact of products and systems. It is standardized by ISO 14040&14044:2006 and has widely been applied to batteries. The European Commission has also developed the Product Environmental Footprint Category Rules (PEFCR) which can be used for calculating the Environmental Footprint profile for products, especially batteries.
The analysis shows that the manufacture of the electric vehicle appears to be the most resource-intensive stage, accounting for 75% of the impact. The manufacture of the battery, which requires lithium and cobalt, accounts for 25% of the impact. Consequently, recycling the vehicle at the end of its life becomes a major lever for reducing this impact on abiotic resources. Potentially, it can be reduced by 50% if materials are recovered and recycled, avoiding the use of virgin ores and materials.
In terms of carbon impact, recycling also provides environmental benefits. If the recycled materials are reused to manufacture other batteries and other vehicles, the total carbon impact of electric vehicles can be reduced by up to 34%.
LCA analysis is based on today's available described technology. Solvay is keen to explore optimized ways to increase the saving t/CO2 by recycling.
Partnering to Create a Closed-loop for End-of-life Battery Metals
The Veolia and Solvay consortium, created in September 2020, as part of their partnership to enable the circular economy of EV battery metals in Europe through closed-loop recycling will enable strategic metals from used EV batteries to be extracted and refined into high-purity metals ready to be reused in new batteries. As lithium-ion battery production in Europe is expected to increase drastically, the project aims to reduce the environmental footprint of future EV batteries while securing a local supply source for critical raw materials.
At this stage, the proof of concept has successfully demonstrated Solvay’s hydrometallurgical process’ ability to purify cobalt, lithium, and nickel after Veolia's chemical extraction process from shredded battery cells (“black mass”). The next step is to validate and optimize the process in a pre-industrial setting by running a scaled-down production unit.
Top Solutions for More Environmentally Friendly Recycling
We are leveraging more than 100 years of mining operations knowledge to optimize battery recycling operations. Our portfolio of metal-specific extractants, including CYANEX® reagent for lithium and Interox®, our hydrogen peroxide-based solution used as a reducing agent to increase recycling efficiency, can be used to assemble solvent extraction circuits in a cascade and recover all valuable metals from spent lithium-ion batteries.
Advancing The Circular Economy by Closing The Loop
Solvay’s hydrometallurgical expertise and fundamental understanding of the recycling value chain support the development of a circular economy for EV batteries. Our chemistry closes the loop, moving the industry from a traditional recycling model to a circular, sustainable model, as we recover critical metals at purity levels suitable for use in new batteries. Enhancing our capabilities with partners, our aim is to improve productivity and reduce operating costs while meeting complex recycling challenges.