NASICON type LI13al0.3ti1.7(PO4)3(LATAP) is one of the most promising solid-state electrolytes (SSEs) for achieving high energy density solid-state batteries (SSBs) due to its high ionic conductivity, high voltage stability, and low cost. However, its practical application is limited by insufficient interface compatibility with cathode materials and serious incompatibility with lithium metal. 
Here,Sun Xueliang from the University of Western Ontario, Canada, Yang Luyi from the Shenzhen Graduate School of Peking University, etcAn improved ultra-high-speed, high-temperature sintering (UHS) method, thermal pulse sintering (TPS), is used to achieve fast (10 seconds) integrated sintering of high-voltage solid-state electron beams. By breaking down successive UHS into multiple heat pulses, TPS minimizes undesirable interfacial side effects. First, the thermal pulse treatment is not interface melting, but by inducing latp nanowires (NW) in the voids, the SSE ceramics are significantly densified, which further connect with each other and fill the space, thereby greatly improving the ionic conductivity. Subsequently, a novel graphene oxide-carbon nanotube-MXENE (GCM) layer was fabricated on the negative side of the latp to prevent side reactions with lithium. Thermal shock not only makes the layer morphology uniform and thus better inhibited lithium dendrites, but also promotes the interfacial pathway of Li+. Finally, the thermal pulse tightly welds the cathode to the electrolyte together in a matter of seconds without undesirable phase diffusion. Based on the above-mentioned optimizations, the SSB can be manufactured in up to 46 V. 
Figure 1Thermally inductive interface welding of the positive electrode
In conclusion, this work proposes a scalable, controllable thermopulse sintering method to fabricate SSBs to overcome the interface problems between cathode materials, latp electrolytes, and lithium metals. The rapid thermal shock process increases the density of LAPP SSES by inducing the growth of LATAP-NWS, which fills the voids and increases ionic conductivity. At the same time, a compact protective layer (GCMP) is constructed on the negative side, providing an additional Li+ conduction pathway, resulting in a stable and robust latp Li interface. In addition, a strong but transient thermal pulse facilitates the rapid welding of the surface between the cathode and the SSE, thus facilitating interfacial contact without causing harmful side reactions. Thanks to the proposed sintering strategy, based on 4The 6 V LCO SSB can be recycled stably and provides a high specific capacity of 185 mAh G-1. The assembled LFP-based solid-state battery still holds 500 after 90 cycles8% high capacity. As a result, this work paves the way for the practical application of ISE in high-voltage SSBs. 
Figure 2Electrochemical performance of all-solid-state batteries
interface welding via thermal pulse sintering to enable 4.6 v solid-state batteries,advanced energy materials2023 doi: 10.1002/aenm.202303422