A terahertz chemical microscope has been developed to visualize electric potential distribution on lithium ion battery cathodes during battery operation. A sensing plate comprising a Si film grown epitaxially on a sapphire substrate was used as a terahertz emitter. The amplitude of terahertz radiation from the sensing plate could be related to the electric potential at the exact point where a femtosecond laser illuminated. Here, the sensing plate was integrated into a conventional can-type lithium ion battery and terahertz radiation from the sensing plate was observed during battery operation between 2.7 and 4.2 V. By scanning the laser, the distribution of terahertz amplitude radiated from the sensing plate was observed, which could be related to the electric potential distribution on the electrodes of the batteries. Localized electric potential could be visualized as the amplitude of terahertz radiation generated in the sensing plate, which was integrated beneath the battery electrode.

中文翻译：

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使用太赫兹化学显微镜测量的锂离子电池阴极上的电势分布

已开发出太赫兹化学显微镜，以可视化电池运行期间锂离子电池阴极上的电势分布。包括在蓝宝石衬底上外延生长的Si膜的感测板用作太赫兹发射器。来自感测板的太赫兹辐射的幅度可能与飞秒激光照亮的确切点处的电位有关。在此，将感应板集成到常规的罐型锂离子电池中，并且在2.7至4.2 V的电池操作期间观察到感应板发出的太赫兹辐射。通过扫描激光，从感应板发出的太赫兹振幅分布为观察到，这可能与电池电极上的电势分布有关。