Non-destructive evaluation of lithium-ion batteries
Inventors
Assignees
Publication Number
US-12276703-B2
Publication Date
2025-04-15
Expiration Date
2043-05-05
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Abstract
A method for non-invasive characterization of an electrical charge storage device such as a lithium battery, containing lithium ions or lithium metal, the method comprising. The method includes the steps of a) providing at least one electric charge storage device; b) measuring a magnetic field generated by the at least one electrical charge storage device using at least one magnetic field sensor positioned in electromagnetic communication_to the electrical charge storage device; c) acquiring magnetic field data; and, d) determining the condition of the at least one electrical charge storage device using the magnetic field data. The method is operable and effective without magnetic shielding from external magnetic fields, including Earth's magnetic field.
Core Innovation
The invention provides a method for non-invasive characterization of electrical charge storage devices such as lithium batteries, which contain lithium ions or lithium metal. This method involves providing at least one electrical charge storage device, measuring the magnetic field generated by the device using at least one magnetic field sensor positioned in electromagnetic communication at various possible distances, acquiring magnetic field data, and determining the condition of the device using the magnetic field data. The approach can operate without the requirement of magnetic shielding from external magnetic fields, including Earth's magnetic field.
The problem addressed by the invention is the lack of a reliable, portable, and non-destructive evaluation (NDE) technique for determining the health state, defects, or performance characteristics of lithium-ion batteries and battery packs. Existing strategies—such as discharge tests, Coulombic counting, open-circuit-potential measurements, electrical-impedance-spectroscopy, and advanced imaging methods like X-ray CT and MRI—have various limitations including impracticality for field or manufacturing floor use, need for specific environments or hardware, resource-intensity, and inability to detect certain defects or subtle structural changes.
This invention solves those limitations by teaching that magnetic field signatures from internal battery materials can be measured, even through ferromagnetic casings, using commercially available magnetometers without special shielding or invasive procedures. The method can determine state-of-charge (SOC), state-of-health (SOH), and detect defects or inhomogeneities within the battery or cell components directly from the acquired magnetic field data. The system is adaptable for use with individual cells, battery packs, or during the manufacturing process for component-level or assembled battery quality and health evaluation.
Claims Coverage
The patent includes one independent claim covering the inventive features of the method for non-invasive characterization of lithium-based electrical charge storage devices.
Non-invasive magnetic field-based characterization of electrical charge storage device
The method includes: 1. Providing at least one electrical charge storage device having a cathode material. 2. Measuring the magnetic field characteristic of the cathode material using at least one magnetic field sensor positioned in electromagnetic communication with the device. 3. Acquiring magnetic field data from this measurement. 4. Determining the condition of the electrical charge storage device using the magnetic field data. - Determination of the device condition does not require a complete circuit or a functional cell.
The inventive features focus on a non-invasive, magnetic field-based method for diagnosing the condition of lithium-based electrical charge storage devices, operable even when the device is not in a complete or functional circuit.
Stated Advantages
The method is non-invasive and non-destructive, so the device under test remains intact and undamaged during measurement.
No magnetic shielding from Earth's magnetic field or other external fields is required, enabling use on the factory floor, in-field, or in real-world environments.
The technique allows for fast, field-portable, and online evaluation of battery health and state-of-charge without requiring specialized or hazardous equipment.
The method is applicable to devices with different casing materials, including ferromagnetic steel and non-magnetic polymer casings.
This approach enables direct detection of battery health, state of charge, and defects from the magnetic field data without further need for calculation or complex modeling.
It permits screening for defects or inhomogeneities in individual battery components or fully assembled devices during manufacturing or after assembly.
Documented Applications
Quality assurance and quality control (QA/QC) on the manufacturing floor for battery components or fully assembled batteries.
In-field diagnostic evaluation of lithium battery packs, such as in electric vehicles or during shipment monitoring.
Post-accident safety screening of electric vehicle battery packs for first responders.
Open-circuit (no-load) and closed-circuit (under load) health and charge monitoring of individual batteries, battery modules, or battery packs.
Screening and identification of defective cells within a multi-cell array or battery pack.
Monitoring state-of-charge and state-of-health non-invasively at any stage in a battery's lifecycle, including pre-use, during use, and post-use.
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