In-situ construction of hybrid artificial SEI with fluorinated siloxane to enable dendrite-free Li metal anodes

Lithium (Li) metal anode holds great promise for high-energy-density rechargeable batteries. However, it suffers from the Li dendrites growth and uncontrollable side reactions with electrolyte due to the un-stable solid electrolyte interphase (SEI) layer. Herein, we propose a facile strategy for the in-situ fabricate of organic-inorganic composite artificial SEI layers on Li surfaces, which consist of organic fluorinated siloxane and inorganic LiF-rich phases. The hybrid artificial SEI endows high mechanical strength (13.1 GPa) and Li+ transfer number (0.62). Such robust SEI protective layers can not only guide uniform nucleation and deposition of Li metal by facilitating uniform Li-ion distribution, but also prevent unfavourable side reactions. Accordingly, the protected metallic lithium anode (PMTFPS-Li) anode en-ables stable Li plating/stripping performance in symmetric cells for more than 300 h at 4 mA center dot h/cm2 under a high areal capacity of 4 mA/cm2. Moreover, the PMTFPS-Li/S cells could maintain more than 300 stable cycles at 0.5C and the PMTFPS-Li/LFP cells present excellent cycling performance (400 cycles at 1C) and enhanced rate capability (110.4 mA center dot h/g at 3 C). This work will inspire the design of artificial SEI on Li anodes for advanced Li metal batteries.(c) 2022 The Authors. Published by Elsevier B.V. on behalf of The Chinese Ceramic Society. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

In this study, a facile strategy was proposed to in-situ fabricate organic-inorganic composite artificial solid electrolyte interphase (SEI) layers on lithium (Li) surfaces. The hybrid artificial SEI exhibited high mechanical strength and Li+ transfer number, enabling uniform nucleation and deposition of Li metal and preventing unfavorable side reactions. This work inspires the design of artificial SEI for advanced Li metal batteries.