Recent progress in non-destructive magnetic field-based imaging techniques for lithium-ion batteries and future perspectives

This review provides a comprehensive examination of non-destructive magnetic field-based imaging techniques for advanced diagnostics and monitoring of lithium-ion batteries. Two primary methodological approaches are systematically analyzed: magnetic resonance imaging methods, which detect state-of-charge via magnetic susceptibility variations, and direct magnetic field imaging techniques, which visualize internal current distributions. These methods enable non-invasive probing of key battery states and structural defects, offering a fundamental advantage over conventional monitoring techniques that rely on external electrical parameters. Their capacity for module-level, non-contact assessment also presents significant potential in applied scenarios, including the screening of retired batteries, demonstrating the potential to transition from laboratory characterization toward practical application. This review synthesizes recent advances, consolidates the current landscape of the technology, identifies major existing barriers, and provides forward-looking insights, ultimately aiming to advance the field toward intelligent battery management.