Powder Aerosol Deposition, a Novel Way for Processing Garnet Solid Electrolytes to fabricate All-Solid-State Batteries

Titelangaben

Hennerici, Lukas ; Linz, Mario ; Schamel, Maximilian ; Nazarenus, Tobias ; Kita, Jaroslaw ; Danzer, Michael A. ; Moos, Ralf:
Powder Aerosol Deposition, a Novel Way for Processing Garnet Solid Electrolytes to fabricate All-Solid-State Batteries.
2023
Veranstaltung: The 4th World Conference on Solid Electrolytes for Advanced Applications, Garnets and Competitors , 04.-07. September 2023 , Tromsø, Norway.
(Veranstaltungsbeitrag: Kongress/Konferenz/Symposium/Tagung , Poster )

Angaben zu Projekten

Abstract

In recent years, much research work has been devoted to optimize garnet-like LLZO as a promising electrolyte material for ASSBs. Here, the focus was particularly on the adaptation of the material and its electrochemical properties with respect to application in an ASSB [1]. Since significant progress has been made in the above-mentioned fields, the next step is to find a processing method, which is suitable for mass production. The desired process should enable the fabrication of dense ceramic films utilizing economic processes that are suitable to manufacture film thicknesses in the range of 5 to 20 μm, in order to explore and to exploit the full potential of ASSB. However, conventional ceramic processing methods such as tape casting require high temperature sintering steps that lead to prohibitively high processing costs. The novel Powder Aerosol Deposition (PAD) is a suitable candidate with promising properties for processing LLZO. PAD enables the production of dense ceramic films at room temperature. In addition, the layer thickness can be arbitrarily adjusted in the range of a few μm up to 200 μm, depending on the respective application. The so called “Room Temperature Impact Consolidation” (RTIC), the characteristic deposition mechanism of the PAD process, negatively affects the electrical properties of PAD films. Resulting stresses within the film and a distorted crystal lattice impede charge carrier transport in comparison to bulk materials. First investigations show that for PAD-LLZO films only a thermal post-treatment at mild temperatures up to 400 °C after deposition is necessary to ensure a competitive ionic conductivity of the films. Furthermore, it was already shown that PAD-LLZO films can be cycled in a Li | LLZO | Li symmetrical cell setup. Based on these results, we aim at showing that PAD-LLZO films can be successfully applied to ASSBs. SEM images and EDX analyses show that a PAD multilayer film consisting of an NMC cathode, an NMC/LLZO composite cathode and an LLZO film with a dense and nanocrystalline structure can be obtained using PAD. In addition, polarization experiments confirm that an NMC | NMC/LLZO | LLZO | Li full cell can be cycled, which has not been shown before. Finally, we are identifying the remaining challenges for PAD-LLZO films or ASSBs before commercial use is feasible. Additionally, we show how a future PAD-based ASSB could be fabricated on a commercial scale and illustrate the potential of such an ASSB using a theoretical consideration of energy densities in respect to cathode layer thickness.