Affiliation:
1. Graduate School of Information Science and Technology Hokkaido University N14W9, Kita Sapporo 060‐0814 Japan
2. Research Institute for Electronic Science Hokkaido University N20W10, Kita Sapporo 001–0020 Japan
3. SANKEN Osaka University Mihogaoka 8‐1 Ibaraki Osaka 567‐0047 Japan
Abstract
AbstractThermal switches that switch the thermal conductivity (κ) of the active layers are attracting increasing attention as thermal management devices. For electrochemical thermal switches, several transition metal oxides (TMOs) are proposed as active layers. After electrochemical redox treatment, the crystal structure of the TMO is modulated, which results in the κ switching. However, the κ switching width is still small (<4 W m−1 K−1). In this study, it demonstrates that LaNiOx‐based solid‐state electrochemical thermal switches have a κ switching width of 4.3 W m−1 K−1. Fully oxidized LaNiO3 (on state) has a κ of 6.0 W m−1 K−1 due to the large contribution of electron thermal conductivity (κele, 3.1 W m−1 K−1). In contrast, reduced LaNiO2.72 (off state) has a κ of 1.7 W m−1 K−1 because the phonons are scattered by the oxygen vacancies. The LaNiOx‐based electrochemical thermal switch is cyclable of κ and the crystalline lattice of LaNiOx. This electrochemical thermal switch may be a promising platform for next‐generation devices such as thermal displays.