This configuration is a classic Electrolyte-Supported Cell (ESC) cathode functional gradient. By using a composite LSM-GDC layer between the SSZ (Scandia-Stabilized Zirconia) electrolyte and the pure LSM (Lanthanum Strontium Manganite) current collector, you are addressing the primary weakness of LSM: its limited ionic conductivity.

SSZ Electrolyte (Support): The active material is typically 10Sc1CeSZ or 10Sc1AlSZ (150–200 um). SSZ provides superior oxygen ion conductivity compared to YSZ at 700°C–850°C. SSZ can be reactive with Strontium-containing cathodes. While LSM is less reactive than LSCF, the interface still needs careful thermal management during sintering.

LSM-GDC Composite (Active Functional Layer): LSM is primarily an electronic conductor with poor oxygen ion porosity. By mixing it with GDC (an ionic conductor), the oxygen reduction reaction (ORR) can happen throughout the bulk of this layer rather than just at the 2D interface of the electrolyte. Unlike YSZ, GDC does not readily form the insulating SrZrO3 phase when in contact with LSM, making it an excellent "bridge" material.

LSM (Current Collection Layer): Its role is mainly to provides a high-conductivity path for electrons from the external circuit (mesh/interconnect) to the active sites. This layer is usually coarser and more porous than the functional layer to allow easy O2 gas diffusion to the active interface.

Part Number	CSOFECESCLLS (C-SOFEC-ESC-LLS)
Cell Composition	Cathode with Bilayers: LSM/LSM-GDC (D-12.5 mm, T=~50 um) Electrolyte: SSZ (D=20 mm, T=~130-170 um)
Button Cell Size	(1) D=20 mm (2) D=25 mm
Package Grade	1 pcs/pack (bulk quantity can be supplied upon request and certain discount will be applied)

References:

1. Z. Drach, et al., Impedance spectroscopy analysis inspired by evolutionary programming as a diagnostic tool for SOEC and SOFC, Solid State Ionics, 2016, 288, 307-310.
2. N. Q. Minh, et al., Sputtered Thin-Film Solid Oxide Fuel Cells, ECS Trans., 2021, 103 67.