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

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.