Dynamic Evolution of All-Solid-State Li-ion Battery Based on LAGP Solid Electrolyte Using In Situ Electrochemical TEM

International audience ; The increasing request for electric vehicles (EV) demands high energy density batteries, wide temperature compatibility and improved safety technology. Solid-state Li-ion batteries (SSB)1 could represent a possible future solution for current battery technology as the liquid electrolyte containing flammable organic materials is replaced by a solid electrolyte (SE) removing the safety concerns. Moreover, SSB technology offers the possibility to use high voltage cathode materials as some SE present wide electrochemical window and also opens the possibility to use lithium metal as anode resulting in batteries with a higher energy density2.SSB performances improved over the last years, but there are still challenges as interfaces, grain boundaries formation, generation of cracks and dendrites during the cycling which needs to be solved in order to make them a sustainable future battery technology2–4. To get a better insight into the limiting parameters of SSB performances comprehensive information about the dynamic process occurring at the interfaces between the solid electrolyte and the electrodes during the electrochemical reaction at nanoscale are essential, thus in-situ experiments are being required. in situ Transmission Electron Microscopy (TEM)5,6 represents the perfect tool for understanding the failure mechanism in ASSB as it allows us to visualize the interfaces, will enable us to follow the structural changes using electron diffraction and 4D-STEM as well as the chemical changes using EDX and EELS mapping.During this study, SSB containing Li1.5Al0.5Ge1.5(PO4)3 (LAGP) oxide solid electrolyte due to their high stability in the air, LiFePO4 (LFP) as positive electrode and Li3V2(PO4)3 (LVP) as negative electrode allowing us to obtain a full inorganic solid-state battery in one single shot using Spark Plasma Sintering (SPS)7.In situ TEM experiment carried out using our microbattery obtained by Focused Ion Beam (FIB) and connected on Protochips chip revealed the simultaneous process of ...