All‐Solid‐State Garnet‐Based Lithium Batteries at Work–In Operando TEM Investigations of Delithiation/Lithiation Process and Capacity Degradation Mechanism

Advanced Science, vol. 10, pp. e2205012

Abstract

Abstract Li7La3Zr2O12 (LLZO)‐based all‐solid‐state Li batteries (SSLBs) are very attractive next‐generation energy storage devices owing to their potential for achieving enhanced safety and improved energy density. However, the rigid nature of the ceramics challenges the SSLB fabrication and the afterward interfacial stability during electrochemical cycling. Here, a promising LLZO‐based SSLB with a high areal capacity and stable cycle performance over 100 cycles is demonstrated. In operando transmission electron microscopy (TEM) is used for successfully demonstrating and investigating the delithiation/lithiation process and understanding the capacity degradation mechanism of the SSLB on an atomic scale. Other than the interfacial delamination between LLZO and LiCoO2 (LCO) owing to the stress evolvement during electrochemical cycling, oxygen deficiency of LCO not only causes microcrack formation in LCO but also partially decomposes LCO into metallic Co and is suggested to contribute to the capacity degradation based on the atomic‐scale insights. When discharging the SSLB to a voltage of ≈1.2 versus Li/Li+, severe capacity fading from the irreversible decomposition of LCO into metallic Co and Li2O is observed under in operando TEM. These observations reveal the capacity degradation mechanisms of the LLZO‐based SSLB, which provides important information for future LLZO‐based SSLB developments.

Authors 10

1. An‐Yuan Hou

   National Yang Ming Chiao Tung University

   Affiliation as printed

   Department of Materials Science and Engineering National Yang Ming Chiao Tung University Hsinchu 30010 Taiwan

   Department of Materials Science and Engineering, National Yang Ming Chiao Tung University, Hsinchu, 30010 Taiwan

2. Chih‐Long Tsai

   Forschungszentrum Jülich

   Affiliation as printed

   Institut für Energie– und Klimaforschung (IEK‐9: Grundlagen der Elektrochemie) Forschungszentrum Jülich D‐52425 Jülich Germany

3. Chun‐Wei Huang

   National Yang Ming Chiao Tung University · Feng Chia University

   Affiliation as printed

   Department of Materials Science and Engineering Feng Chia University No. 100, Wenhwa Rd Seatwen Taichung 40724 Taiwan

   Department of Materials Science and Engineering National Yang Ming Chiao Tung University Hsinchu 30010 Taiwan

   Department of Materials Science and Engineering, Feng Chia University, No. 100, Wenhwa Rd, Seatwen, Taichung, 40724 Taiwan

4. Roland Schierholz

   Forschungszentrum Jülich

   Affiliation as printed

   Institut für Energie– und Klimaforschung (IEK‐9: Grundlagen der Elektrochemie) Forschungszentrum Jülich D‐52425 Jülich Germany

5. Hung‐Yang Lo

   National Yang Ming Chiao Tung University

   Affiliation as printed

   Department of Materials Science and Engineering National Yang Ming Chiao Tung University Hsinchu 30010 Taiwan

   Department of Materials Science and Engineering, National Yang Ming Chiao Tung University, Hsinchu, 30010 Taiwan

6. Hermann Tempel

   Forschungszentrum Jülich

   Affiliation as printed

   Institut für Energie– und Klimaforschung (IEK‐9: Grundlagen der Elektrochemie) Forschungszentrum Jülich D‐52425 Jülich Germany

7. Hans Kungl

   Forschungszentrum Jülich

   Affiliation as printed

   Institut für Energie– und Klimaforschung (IEK‐9: Grundlagen der Elektrochemie) Forschungszentrum Jülich D‐52425 Jülich Germany

8. Rüdiger‐A. Eichel Aachen Institut für Materialien und Prozesse für elektrochemische Energiespeicher– und wandler

   Forschungszentrum Jülich · Helmholtz-Institute Münster · RWTH Aachen University

   Affiliation as printed

   Institut für Energie– und Klimaforschung (IEK‐9: Grundlagen der Elektrochemie) Forschungszentrum Jülich D‐52425 Jülich Germany

   Institut für Energie– und Klimaforschung (IEK–12: Helmholtz–Institute Münster Ionics in Energy Storage) Forschungszentrum Jülich D‐48149 Münster Germany

   Institut für Materialien und Prozesse für elektrochemische Energiespeicher– und wandler RWTH Aachen University D‐52074 Aachen Germany

9. Jeng‐Kuei Chang

   National Yang Ming Chiao Tung University

   Affiliation as printed

   Department of Materials Science and Engineering National Yang Ming Chiao Tung University Hsinchu 30010 Taiwan

   Department of Materials Science and Engineering, National Yang Ming Chiao Tung University, Hsinchu, 30010 Taiwan

10. Wen‐Wei Wu corresponding

    National Yang Ming Chiao Tung University

    Affiliation as printed

    Center for the Intelligent Semiconductor Nano‐system Technology Research Hsinchu 30078 Taiwan

    Department of Materials Science and Engineering National Yang Ming Chiao Tung University Hsinchu 30010 Taiwan

    Center for the Intelligent Semiconductor Nano-system Technology Research, Hsinchu, 30078 Taiwan

    Department of Materials Science and Engineering, National Yang Ming Chiao Tung University, Hsinchu, 30010 Taiwan