Non-invasive, UV/vis-based monitoring of the lithiation degree of prelithiated lithium-ion batteries

TO-108 • PT 1.2934 • As of 10/2023
Institute of Energy and Climate Research
Ionics in Energy Storage (IEK-12)

Technology

The technology is based on optical method for determining the degree of lithiation in electrode layers for Li-ion batteries. It aims to improve the performance, longevity, and cost efficiency of rechargeable batteries, particularly for consumer electronics and electric vehicles. Lithium-ion-based cells offer high energy density and the reversible storage of Li-ions in the electrodes is crucial for their operation. Conventional methods for determining lithium content are not suitable for industrial production processes. The proposed optical method allows for non-destructive, on-line monitoring of lithium content in electrode materials.

Problem addressed

Existing methods for determining lithium content in electrodes, such as electrochemical or chemical-analytical methods, are not feasible for industrial-scale production. These methods require separate sampling and analysis, making real-time process control impossible. Additionally, they do not provide statistically significant information about variations in lithium content over time or across the electrode roll.

Solution

The invention introduces an optical method that overcomes the limitations of previous techniques. The proposed method accurately and rapidly determines the amount of lithium ions in electrode layers. By calibrating known samples, the method utilizes reflection measurements to quantify the lithium content, even in complex electrode structures with multiple active materials. The method can be applied in an industrial setting, allowing for continuous, non-destructive monitoring of lithium content in electrode materials.

Benefits and Potential Use

The optical method offers a precise and adaptable approach for determining the degree of lithiation in electrode layers for Li-ion batteries. It can be used in various electrode sizes, providing either localized or statistically averaged measurements. The method is particularly suitable for electrode layers with mixed silicon/X active materials. The invention also includes a system for in-line determination of lithiation degree during electrode production, enabling continuous process control and assessment of lithiation variations.

Development Status and Next Steps

Forschungszentrum Jülich has extensive expertise in this field and holds several patents. The technology described above has already been initially verified through prototypes and is continuously being developed further. The Institute of Energy and Climate Research (IEK-12) – Ionics in Energy Storage – already cooperates with numerous national and international companies and scientific partners. Forschungszentrum Jülich focuses on energy and cost-efficient devices, suitable for various emerging technologies. We are continuously seeking for cooperation partners and/or licensees in this and adjacent areas of research and applications.

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