Editors: | F. Kongoli, F. Marquis, N. Chikhradze, T. Prikhna, M. De Campos, S. Lewis, S. Miller, S. Thomas. |
Publisher: | Flogen Star OUTREACH |
Publication Year: | 2022 |
Pages: | 290 pages |
ISBN: | 978-1-989820-68-1(CD) |
ISSN: | 2291-1227 (Metals and Materials Processing in a Clean Environment Series) |
In the composite cathode of all-solid-state Li-metal batteries (ASSBs), the high interfacial resistance and unstable interphase between the cathode active material (CAM) and solid-state electrolyte (SSE) are two of the main reasons for the low energy density in current ASSBs [1] . Matching the physical/(electro)chemical properties of the CAM and SSE is vital to obtaining a stable interface/interphase in the composite cathode [2]. Li1.3Al0.3Ti1.7(PO4)3 (LATP) is a promising candidate as a Li+ conductive component in all-phosphate-based composite cathode produced by a co-firing method due to its good thermal chemical stability against phosphate-based CAMs [3]. Herein, with the effort to optimize the synthesizing and sintering process of LATP, highly-conductive LATP is obtained at a low sintering temperature [4]. Consequently, the phosphate-based CAM/LATP interface in composite cathode is stabilized, which significantly improves the energy density of ASSBs.
Specifically, a high-density, fully phosphate-based composite cathode is prepared by co-firing LiFePO4 (LFP) and (LATP). In this way, an ion-conductive and redox-active Li3-xFe2-x-yTixAly(PO4)3 (LFTAP) interphase is formed at the interface between LFP and LATP after heating, which not only improves the adhesion of materials but also provides additional capacity. The structure of the fabricated composite cathode is studied in detail. The electrochemical performance and the influence of the electrochemically active LFTAP interphase and LATP solid-electrolyte of the corresponding ASSBs composed of the co-fired LFP/LATP composite cathodes are investigated.