How to Optimize Lithium-Ion Battery Recycling with Handheld XRF

The transition to a low-carbon economy and the rise of electric vehicles are expected to drive an exponential increase in the demand for lithium-ion batteries. Consequently, the International Energy Agency projects that the need for certain critical commodities will rise significantly over the next two decades.

Copper (Cu) demand is forecasted to grow by over 40 %, while nickel (Ni) and cobalt (Co) are expected to see increases of 60-70 % each, and lithium (Li) demand is projected to surge by nearly 90 %.¹ This growing demand will likely lead to increased mining activities, potentially resulting in higher volumes of harmful waste.

To mitigate environmental impacts and reduce dependence on scarce commodities with economic and geopolitical consequences, several countries have introduced regulations addressing the responsibilities of producers and manufacturers.

These regulations incorporate incentives and accountability guidelines for lithium-ion battery and electric vehicle manufacturers. The aim is to facilitate the launch of a circular economy that will increasingly contribute to the supply of strategic raw materials through sustainable recycling techniques.

Lithium-ion batteries are composed of various components, with the cathode being the most valuable, accounting for 40 % to 70 % of the battery's total value, depending on its specific chemistry.^3,4

As of 2023, lithium nickel cobalt manganese (NCM) oxides make up 66 % of the cathode active materials in lithium-ion batteries for electric vehicles. Lithium iron phosphate (LFP) accounts for 24 %, while lithium nickel cobalt aluminum oxide (NCA) comprises the remaining 10 %.³

Lithium-Ion Battery Recycling Workflow

Several methods are available for recycling lithium-ion batteries, involving various combinations of thermal and mechanical treatments, as well as pyrometallurgical or hydrometallurgical processes.

A common recycling workflow begins with discharging the batteries, followed by dismantling the battery pack and modules to access the battery cells.

In the next phase, the cells are shredded, sieved, and separated using density and magnetism. During this stage, current collectors—typically aluminum and copper foils—are separated from the black mass, a powder containing active materials from the cathode (NCM, LFP, NCA) and the anode (graphite).

In the next stage, black mass can undergo several chemical treatments in hydrometallurgical processes to recover pure lithium, nickel, cobalt, and manganese salts. Alternatively, the black mass can be directly smelted (pyrometallurgy) to recover cobalt, nickel, and sometimes copper as a metal alloy, while lithium is transferred to the slag phase.

After pyrometallurgy, the resulting alloy is further refined into pure base metal salts through simplified hydrometallurgical processes. It is important to note that not all recycling routes are economically viable for every type of cathode material.

The Need for Rapid Chemical Analysis Throughout the Recycling Workflow

The recycling of lithium-ion batteries is complex due to the high variability of input materials and the multiple process steps required to recover valuable commodities.

Recovered materials typically need to be analyzed after each major step to verify their purity or ensure the proper composition for the next stage. Additionally, companies upstream in the recycling process, where black mass is recovered, must assess the market value of spent battery materials before shipping them to downstream recyclers.

Laboratory analysis of these materials can be both time-consuming and costly, sometimes exceeding the value of the material itself. This highlights the need for cost-effective, on-site analysis methods to enable fast, real-time decisions during the recycling process.

Handheld X-Ray Fluorescence Analysis

Handheld X-ray fluorescence (HHXRF) analysis is a proven, cost-effective elemental analysis technique widely used in recycling industries such as scrap metal and automotive catalytic converters. HHXRF can detect elements ranging from magnesium (Mg) to uranium (U) in various materials, including metals, alloys, ceramics, ores, and plastics.

The Thermo Scientific^™ Niton^™ XL2 and Thermo Scientific^™ Niton^™ XL5 Plus Handheld XRF Analyzers provide accurate, real-time elemental analysis with minimal sample preparation throughout multiple steps of the lithium-ion battery recycling process.

While HHXRF cannot detect lithium, it can measure most elements in the periodic table, such as nickel and cobalt, which often hold greater value than lithium in a lithium-ion battery.⁴

Handheld XRF is predominantly used upstream of the recycling process:

• HHXRF can identify the type of cathode scrap films from gigafactories, which account for approximately 70 %⁴ of the feedstock in battery recycling. Determining the cathode material (Figure 1) is crucial for selecting the appropriate recycling route. For instance, pyrometallurgy (smelting) is highly effective at recovering nickel and cobalt from NCM cathode films but is unsuitable for LFP cathode films. In LFP materials, lithium is the only valuable commodity, and during pyrometallurgy, it transfers to the slag phase, making its recovery through further hydrometallurgical processes costly.
• For end-of-life batteries, HHXRF can be utilized early in the recycling process to sort the housings from dismantled batteries, which are typically composed of various grades of stainless steel or aluminum alloys. Additionally, HHXRF is used after processes like shredding, magnetic and density separation, and sieving of battery cells to examine the resulting materials. These include copper and aluminum foils as well as black mass. By analyzing these fractions, HHXRF provides critical insights for risk assessment, such as confirming the absence of toxic metals, ensuring proper material handling, and optimizing process efficiency. The black mass, being the most valuable component, can be assessed for nickel, cobalt, manganese, and other elements with minimal preparation. This analysis can be performed directly in bags for rapid, semi-quantitative results (Figure 2a), or using sample cups with a test stand for more accurate, detailed measurements (Figure 2b). In this more precise method, additional elements like phosphorus, silicon, and aluminum can also be measured alongside nickel, cobalt, manganese, copper, and iron.

Handheld XRF can also be used to quickly and accurately analyze the main product from smelting (pyrometallurgy) and measure the amount of cobalt, copper, and nickel in the alloy.

Figure 1. Sorting production scrap with HHXRF by identifying types of scrap cathode films. Image Credit: Thermo Fisher Scientific – Handheld Elemental & Radiation Detection

Figure 2. Workflow for rapid analysis of black mass: (a) semi-quantitative analysis of black mass in bags (base metals such as copper, nickel, cobalt, or manganese) using the Niton XL2 XRF Analyzer; (b) quantitative analysis of the full element range from Mg–U in sample cups using the Niton XL5 Plus XRF Analyzer. Image Credit: Thermo Fisher Scientific – Handheld Elemental & Radiation Detection

Conclusion

There is no single ideal process for recycling lithium-ion batteries that balances low environmental impact, high metal recovery rates, and economic viability. Due to the diversity of technologies and materials involved, recycling lithium-ion batteries is a complex process with multiple potential approaches.

HHXRF supports recyclers by providing real-time, lab-quality data, enabling them to optimize processes and make quick, informed decisions, which offer several key benefits:

• Preventing unwanted materials containing heavy metals, such as lead or cadmium, from entering subsequent phases in the recycling workflow.
• Materials can be accurately sorted, and the appropriate recovery processes can be selected based on the material type (e.g., LFP vs. NCM).
• The economic value of both incoming and outgoing materials can be more accurately assessed.

References and Further Reading

1. International Energy Agency, The Role of Critical Minerals in Clean Energy Transitions, March 2022, www.iae.org.
2. Robert Bird, Zachary J. Baum, Xiang Yu, Jia Ma, The Regulatory Environment for Lithium-Ion Battery Recycling ACS Energy Lett. 2022, 7, 736−740
3. Heiner Heimes et al., Recycling von Lithium-Ionen-Batterien, 2. Edition, Dec 2023, PEM RWTH Aachen University & VDMA, ISBN: 978-3-947920-43-3
4. Julia Harty, Six key trends in the battery recycling market, June 2023, Fastmarkets https://www.fastmarkets.com/insights/six-key-trends-battery-recycling-market/

This information has been sourced, reviewed and adapted from materials provided by Thermo Fisher Scientific – Handheld Elemental & Radiation Detection.

For more information on this source, please visit Thermo Fisher Scientific – Handheld Elemental & Radiation Detection.