Forming Robust and Highly Li-Ion Conductive Interfaces in High-Performance Lithium Metal Batteries Using Chloroethylene Carbonate Additive

Developing high-rate Li metal batteries (LMBs) is challenging because of dendrite growth and irreversible parasitic reactions of the Li metal. Herein, a robust and highly ion-conductive solid electrolyte interphase (SEI) layer is designed on a Li metal anode and a Ni-rich layered cathode by incorporating chloroethylene carbonate (ClEC) as an additive in fluoroethylene carbonate-based electrolytes. ClEC induces the formation of LiCl, which facilitates Li-ion diffusion in the robust LiF-rich SEI layer, thereby improving the cycle stability of the Li metal anode and suppressing microcracking of the Ni-rich layered cathode, especially during charging and discharging at high current densities. By using the newly developed combination of electrolyte solution, an LMB featuring the Li[Ni0.78Co0.1Mn0.12]O2 cathode (2.3 mAh cm-2, 0.1 C) affords a superior capacity retention of 80.2% over 400 cycles at high charge and discharge current densities of 2.0 C (3.6 mA cm-2) and 5.0 C (9.0 mA cm-2). This study provides insights into the use of ClEC as an electrolyte additive and highlights the importance of constructing robust and highly ion-conductive interfaces on both Li metal anodes and Ni-rich cathodes for high-performance LMBs. Fast and stable cycling of lithium metal batteries is achieved by a robust and highly ionic conductive interphase, formed in a lithium metal anode and Ni-rich layered cathode. Proposed electrolyte solution using chloroethylene carbonate additive induces the dense lithium growth and suppresses the cathode microcking.image (c) 2023 WILEY-VCH GmbH

Automated summary

By incorporating chloroethylene carbonate (ClEC) as an additive, a robust and highly ion-conductive solid electrolyte interphase (SEI) layer is designed, improving the cycle stability of the Li metal anode and suppressing microcracking of the Ni-rich layered cathode.