Solid electrolyte/graphite composite particle for an all-solid-state lithium-ion battery

Abstract

A great issue in the development of an all-solid-state lithium-ion battery (ASSLIB) is the fabrication of a composite electrode with good contact between active materials (AMs) and solid electrolytes (SEs). To overcome this challenge, it is important to develop a powder processing technology that produces composite particles of AMs and SEs. In this study, we investigated a dry impact blending process for producing graphite composite particles (typical anode AM) and sulfide SEs. First, by controlling the rotating speed of the rotor in the dry impact blending process, two types of composite particles, namely surface-coated (SC) composite particles with no graphite breakage and matrix-type (MT) composite particles with graphite breakage, were produced. The SC composite particles showed higher electrochemical performance than the MT composite particles due to less change in the graphite crystallinity. Second, the longer the processing times for the preparation of SC composite particles, the higher the SE coating on graphite, resulting in higher electrochemical performance. Third, we demonstrated that the SC composite particles exhibited higher electrochemical performance than those prepared using a conventional lab-scale mixing technique. We demonstrated the effectiveness of the dry impact blending process for the preparation of an anode composite electrode for ASSLIBs.