All-solid-state batteries (ASSBs) are at the forefront of lithium-ion battery technology. Among present ASSBs, bilayer ASSBs, which use two solid electrolytes instead of just one, are considered the ideal candidates for next-generation batteries. However, there is presently little information on the optimal combination of electrolytes for use in these bilayer batteries.
Now, in a new study published in ACS Energy Letters, researchers from the Research Institute for Sustainable Energy (RISE), TCG CREST, have investigated the electrochemical stability of different halide solid electrolytes and sulphide solid electrolytes and suggested a guideline for selecting the best combination of the two. Their findings indicate that lower electronegativity of the central metal atom in the halide solid electrolyte is critical to the long-term stability of the bilayer ASSB.