Microstructure and electrical conductivity of Mo/TiN composite powder for alkali metal thermal to electric converter electrodes

作者：Kim Sun Dong^*; Kim Se Young; Joo Jong Hoon; Woo Sang Kuk

来源：Ceramics International, 2014, 40(3): 3847-3853.

DOI：10.1016/j.ceramint.2013.08.025

• A. Grain growth
• Alkali metal thermal to electric converter
• Mo/TiN composite
• Core-shell
• Thermal cycling

A Mo/TiN composite powder has been synthesized by a sol gel method to improve the electrical performance and microstructural stability of the alkali metal thermal to electric converter electrode. The core (TiN)-shell (Mo) structure of the composite powder is confirmed by energy-dispersive X-ray spectroscopy and scanning electron microscopy. The composite powder is primarily composed of submicron (400-800 nm) particles that are coated on a core ( > 3-5 mu m) particle. The Mo/TiN composite electrode exhibits high electrical conductivities of 1000 Scm(-1) at 300 degrees C and 260 Scm(-1) at 700 degrees C in an Ar atmosphere. The electrode exhibits excellent tolerance against grain growth during thermal cycling tests (R.T.<-> 800 degrees C), where the average growth rate of Mo grains in the Mo/TiN composite electrodes is controlled less than 0.5%/time (0.62 -> 0.65 mu m), while the growth rate in Mo electrodes is 306.7%/time (0.24 -> 3.92 mu m). It can be concluded that the Mo/TiN composite powder will suppress the degradation of the electrode and enhance the performance and durability of the unit cell at elevated temperatures.