A Li battery consisting of a high energy capacity oxide cathode (e.g. NMC, NCA), a Li metal anode, and a sulfide-based glass ceramic solid electrolyte (SE), is a possible pathway to overcome the challenges of liquid electrolyte cells, namely dendrite growth and safety concerns without compromising high energy density. Even though the conductivity of a few sulfide solid electrolytes (SSEs) surpasses that of liquid electrolytes, multiple interfacial phenomena at both the cathode and anode interfaces play a crucial role in affecting efficient battery performance. Such phenomena include solid-electrolyte interphase (SEI) formation and mechanical deformation; the SEI forms due to poor chemical and electrochemical stability of SSEs while mechanical deformation arises from volume changes experienced by the cathode during cycling and also the rigid nature of SSEs. In the past several decades, tremendous effort has been made to study the SEI for SSEs, however, the properties of cathodic and anodic SEIs and their effects on long-term All Solid State Battery (ASSB) cycling are still not well-understood. In this study, we applied an argyrodite- (Li6PS5Cl) based Li ion conducting SSE for fabrication of an all solid-state Li-metal battery. Although it is not fully understood, part of the irreversible capacity loss arising at the 1st cycle is due to electrochemical decomposition of the SSE at both the cathode and anode interfaces. The SEI was characterized via X-ray photoelectron spectroscopy (XPS), Raman spectroscopy and the results are compared with DFT-based calculations. The results reveal the critial role of the SEI on long-term performance of room-temperature ASSBs and we will discuss the details in the presentation.

Understanding the interfacial phenomena for all-solid-state batteries (ASSB) comprising sulfide based solid electrolytes

256th National Meeting (2018)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.