Interfacial Architecture for Extra Li(+) Storage in All-Solid-State Lithium Batteries

The performance of nanocomposite electrodes prepared by controlled ball-milling of TiS(2) and a Li(2)S–P(2)S(5) solid electrolyte (SE) for all-solid-state lithium batteries is investigated, focusing on the evolution of the microstructure. Compared to the manually mixed electrodes, the ball-milled electrodes exhibit abnormally increased first-charge capacities of 416 mA h g(−1) and 837 mA h g(−1) in the voltage ranges 1.5–3.0 V and 1.0–3.0 V, respectively, at 50 mA g(−1) and 30°C. The ball-milled electrodes also show excellent capacity retention of 95% in the 1.5–3.0 V range after 60 cycles as compared to the manually mixed electrodes. More importantly, a variety of characterization techniques show that the origin of the extra Li(+) storage is associated with an amorphous Li–Ti–P–S phase formed during the controlled ball-milling process.