Observation of chemo-mechanical failure and influence of cut-off potentials in all-solid-state Li-S batteries

02 April 2019, Version 2
This content is a preprint and has not undergone peer review at the time of posting.

Abstract

Owing to a remarkably high theoretical energy density, the lithium-sulfur (Li-S) battery has attracted significant attention as a candidate for next-generation batteries. While employing solid electrolytes can provide a new avenue for high capacity Li-S cells, all-solid-state batteries have unique failure mechanisms such as chemo-mechanical failure due to the volume changes of active materials. In this study, we investigate all-solid-state Li-S model cells with differently processed cathode composites and elucidate a typical failure mechanism stemming from irreversible Li2S formation in the cathode composites. Reducing the particle size is key to minimizing the influence of volume changes and a capacity of over 1000 mAh gsulfur-1is achieved by ball-milling of the cathode composites. In addition, the long-term stability of the ball-milled cathode is investigated by varying upper and lower cut-off potentials for cycling, which results in unveiling the significantly detrimental role of the lower cut-off potential. Preventing a deep-discharge leads to a reversible capacity of 800 mAh gsulfur-1over 50 cycles in the optimized cell. This work highlights the importance of mitigating chemo-mechanical failure using microstructural engineering as well as the influence of the cut-off potentials in all-solid-state Li-S batteries.

Keywords

solid state battery
solid electrolyte
Li-S battery

Supplementary materials

Title
Description
Actions
Title
Supporting Information
Description
Actions

Comments

Comments are not moderated before they are posted, but they can be removed by the site moderators if they are found to be in contravention of our Commenting Policy [opens in a new tab] - please read this policy before you post. Comments should be used for scholarly discussion of the content in question. You can find more information about how to use the commenting feature here [opens in a new tab] .
This site is protected by reCAPTCHA and the Google Privacy Policy [opens in a new tab] and Terms of Service [opens in a new tab] apply.