Despite the high theoretical capacity and low reduction potential of Li metal, low Coulombic efficiency and safety issues of Li metal batteries have hindered their commercialization. In this work, we explore the processes significantly impacting on Coulombic efficiency and overpotential in Li||Cu asymmetric cells depending on “cycling capacity”. To understand this behavior, we focused on three overshooting peaks in voltage profiles, and as each peak involves both Li plating and stripping at two electrodes, we could extract the six individual processes. Among them, the decreasing values of overpotential with increasing cycling capacity (or equivalently, “cycling time” at a fixed current density) are clearly observed, confirming their influence on cell performance. This comprehensive understanding of Coulombic efficiency, overpotential and morphological evolutions from the perspective of time provides new insight to the performance of Li metal batteries.
Bibliographical noteFunding Information:
S.-H. Y. acknowledges the support by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) ( NRF-2020R1C1C1012308 ) and by Technology Development Program to Solve Climate Changes through the National Research Foundation of Korea (NRF) funded by Ministry of Science and ICT ( NRF-2021M1A2A2038137 ). J. H. U. acknowledges the support provided by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education ( NRF-2021R1I1A1A01044891 ).
© 2022 Elsevier B.V.
- Coulombic efficiency
- Lithium metal batteries
- Operando optical microscopy
ASJC Scopus subject areas
- Renewable Energy, Sustainability and the Environment
- General Materials Science
- Energy Engineering and Power Technology