Interfacial Engineering at Cathode/LATP Interface for High-Performance Solid-State Batteries

Solid-state rechargeable lithium batteries are considered as one of the promising energy storage technologies due to their safety and high energy density. While developing better solid-state batteries is hampered by the poor interfacial compatibility. In this work, one novel design of buffer layer using the Li _1+x Al _x Ti _2−x (PO ₄ ) ₃ (LATP) solid electrolyte is reported to address the poor compatibility and big migration gap at the electrode-solid electrolyte interface. Such a facile design works well on facilitating the interfacial ionic inter-diffusion by padding the gap of ionic conductivity between electrode and electrolyte, as well as passivating the electric activity of interface region to avoid the continuously interfacial degradation, hence makes the interface more homogeneous and intimate to deliver the superior electrochemical performance. Moreover, upon cycling, a new carbon-rich interphase is revealed from electron microscopy in the interface region, which probably plays an important role in stabilizing the structure and regulating the electron/ion fluxes. All these findings provide a rewarding avenue to resolve the interfacial issues of solid-state lithium ion batteries and the integrated electronic devices.