Towards Sustainable Sulfide‐Based All‐Solid‐State‐Batteries: An Experimental Investigation of the Challenges and Opportunities Using Solid Electrolyte Free Silicon Anodes

Abstract Silicon is one of the most promising anode active materials for future high–energy lithium‐ion‐batteries (LIB). Due to limitations related to volume changes during de–/lithiation, implementation of this material in commonly used liquid electrolyte‐based LIB needs to be accompanied by material enhancement strategies such as particle structure engineering. In this work, we showcase the possibility to utilize pure silicon as anode active material in a sulfide electrolyte‐based all‐solid‐state battery (ASSB) using a thin separator layer and LiNi 0.6 Mn 0.2 Co 0.2 O 2 cathode. We investigate the integration of both solid electrolyte blended anodes and solid electrolyte free anodes and explore the usage of non‐toxic and economically viable solvents suitable for standard atmospheric conditions for the latter. To give an insight into the microstructural changes as well as the lithiation path inside the anode soft X‐ray emission and X‐ray photoelectron spectroscopy were performed after the initial lithiation. Using standard electrochemical analysis methods like galvanostatic cycling and impedance spectroscopy, we demonstrate that both anode types exhibit commendable performance as structural distinctions between two‐dimensional and three‐dimensional interfaces became evident only at high charge rates (8 C).