The 83rd JSAP Autumn Meeting 2022

Presentation information

Oral presentation

3 Optics and Photonics » 3.8 Terahertz technologies (formerly 3.9)

[22p-C201-1~6] 3.8 Terahertz technologies (formerly 3.9)

Thu. Sep 22, 2022 4:00 PM - 5:30 PM C201 (C201)

Yasuo Minami(Tokushima Univ.)

5:15 PM - 5:30 PM

[22p-C201-6] Measurement of conductivity of lithium-ion materials using terahertz spectroscopy

Shoma Murakami1, Anaho Zuo2, Zhe Li2, Isao Morohashi3, Ya Zhang1 (1.Inst. Of Eng., Tokyo Univ. of Agri.&Techno., 2.Tsinghua Univ., 3.NICT)

Keywords:THz time-domain spectroscopy, Lithium-ion nanomaterial

Lithium-ion-based batteries are crucial components in portable electronic devices, electric vehicles and new energy systems. The design of high-performance batteries requires a deep understanding of the instinctive electronic properties of lithium-ion nanomaterials. However, because lithium-ion materials are usually powder-based materials, it is difficult to have a direct measurement of the electronic conductivity by conventional probing methods.
In this research, we have performed terahertz spectroscopy1 for lithium-ion materials to estimate their electrical conductivities. We have mixed lithium-ion material (LCO) with conductive additive carbon powder (AB) and adhesive additive PVDF, and then coated the mixed powder on high-resistivity silicon wafers. The transmission spectra of the samples were measured with a THz time-domain spectrometer. The transmission spectra of samples with various compositions (LCO = 80%, AB = 1-10%) was measured. It has been found that the transmission at the low-frequency band (0.1-0.5 THz) decreases with the increasing proportion of AB, which is explained by the free electron absorption in the AB material. On the other hand, the proportion of LCO barely affects the low-frequency transmission, but gives the low transmission at the high-frequency band (> ~3 THz), indicating that LCO generally works as a dielectric material with resonant absorptions at the high-frequency band. The obtained results would be useful for understanding the electrical properties of LCO materials.