Journal Article

FZJ-2026-05863

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png The Impact of Cobalt Substitution on the Electrochemical Properties of Cubic Li 6.6 La 3 Zr 1.6 Ta 0.4 O 12 Solid Electrolyte for All‐Solid‐State Li‐Ion Batteries

Ahmed, J. (Corresponding author)FZJ*RWTH* ; Barr, J. A.Extern* ; Qin, Z. ; Domgans, A.FZJ*RWTH* ; Kim, K.Extern* ; Tsai, C.-L.FZJ* ; Schierholz, R. (Corresponding author)FZJ* ; Borowec, J.FZJ* ; Wood, B. C.Extern* ; Wan, L. F. (Corresponding author)Extern* ; Windmüller, A.FZJ* ; Hausen, F.FZJ*RWTH* ; Eichel, R.-A.FZJ*RWTH*

2026
Wiley-VCH Weinheim

This record in other databases:  

Please use a persistent id in citations: doi:10.1002/advs.78649

Abstract: Garnet-type Li 7 La3 Zr 2 O12 (LLZO) is a promising solid electrolyte for all-solid-state lithium batteries (SSLB). The diffusion ofcobalt (Co) into LLZO in combination with LiCoO 2 (LCO) as the active cathode material (CAM) is widely reported in FAST/SPS-sintered LCO/LLZO composite cathodes, sintered under an argon (Ar) atmosphere, and associated with degradation. In contrast,air-sintered LCO/LLZO composite cathodes often demonstrate greater cycle stability, indicating an impact of the processingatmosphere. To address this issue, this study systematically investigates the effect of Co substitution in Li 6.6 La3 Zr 1.6 Ta0.4 O12(LLZTO) sintered under both atmospheres. The structural, microstructural, and electrochemical properties of the sinteredmaterials were characterized using XRD, SEM-EDS, Raman spectroscopy, and EIS. DFT calculations were further performedto investigate the thermodynamic stability of Co substitution at different cation sites within the LLZO structure. Our resultsdemonstrate that Co incorporation into the LLZTO lattice is significantly greater under Ar, with Co 2+ occupying Li-positionsaccording to DFT, and total conductivity is reduced. When sintered in air, most of the Co segregated as a secondary phase ofLCO and electronic conductivity is increased. These results identify one possible contribution to the degradation of LCO/LLZTOcomposite cathodes processed under reducing conditions and suggest that post-annealing in air may reverse it.

---

Contributing Institute(s):

1. Grundlagen der Elektrochemie (IET-1)

Research Program(s):

1. 1223 - Batteries in Application (POF4-122) (POF4-122)
2. HITEC - Helmholtz Interdisciplinary Doctoral Training in Energy and Climate Research (HITEC) (HITEC-20170406) (HITEC-20170406)

Appears in the scientific report 2026

---

Database coverage:
; ; ; Article Processing Charges ; Clarivate Analytics Master Journal List ; Current Contents - Physical, Chemical and Earth Sciences ; DEAL Wiley ; DOAJ Seal ; Ebsco Academic Search ; Essential Science Indicators ; Fees ; IF >= 15 ; JCR ; PubMed Central ; SCOPUS ; Science Citation Index Expanded ; Web of Science Core Collection

---