To develop a high-density and long-life lithium-ion battery, a technology is needed that allows non-destructive visualization of the spatial distribution of deteriorated parts after cycle test. In the present study, we measured the distribution of the magnetic field leaking from the lithium-ion battery during its operation. Based on the measurement results, we evaluated the spatial distribution of electric current density that corresponds to the reaction rate of the active material and the ion diffusion rate in the electrolyte solution inside a battery using the electric current reconstruction process. With respect to the changes in the internal state of the lithium-ion battery associated with cycle deterioration, we successfully visualized the part where the electrical conductivity has changed that is the deteriorated part causing the battery capacity to decrease inside the lithium-ion battery.

为了开发高密度和长寿命的锂离子电池，需要一种技术，可以在循环测试后无损可视化劣化部件的空间分布。在本研究中，我们测量了锂离子电池在运行过程中泄漏的磁场分布。根据测量结果，我们使用电流重构过程评估了与活性材料的反应速率和电池内部电解质溶液中的离子扩散速率相对应的电流密度的空间分布。关于锂离子电池与循环劣化相关的内部状态变化，