Electrochemical properties of all-solid-state lithium batteries with amorphous titanium sulfide electrodes prepared by mechanical milling

Abstract

Amorphous titanium trisulfide (TiS₃) active materials were prepared by ball milling of an equimolar mixture of crystalline titanium disulfide (TiS₂) and sulfur. A high-resolution transmission electron microscope image revealed no periodic lattice fringes on the amorphous TiS₃. The all-solid-state lithium secondary batteries using a sulfide solid electrolyte and the amorphous TiS₃ electrode showed high capacity of greater than 300 mAh g⁻¹ for 10 cycles. The amorphous TiS₃ had a higher capacity than the mixture of crystalline TiS₂ and S, which was used as the starting material of amorphous TiS₃. The X-ray diffraction patterns and the Raman spectra of the amorphous TiS₃ electrode after the first and tenth charge–discharge measurements were similar to those before the measurement. The amorphous structure of TiS₃ did not change greatly during the first few cycles. The all-solid-state cells with the amorphous TiS₃ electrode showed higher initial coulombic efficiency because the amorphous TiS₃ active material retained its structure during the initial electrochemical test.