Conformal LiF Stabilized Interfaces via Electrochemical Fluorination on High Voltage Spinel Cathodes (≈4.9 V) for Lithium‐Ion Batteries. Issue 32 (3rd October 2022)

• Record Type: Journal Article
• Authors: Thapaliya, Bishnu P.; Borisevich, Albina Y.; Meyer, Harry M.; Sun, Xiao‐Guang; Bridges, Craig A.; Dai, Sheng
• Is Part Of: Advanced materials interfaces. Volume 9:Issue 32(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-10-03
• Subjects: conformal LiF -- electrochemical fluorination -- electromaterial functionalization -- high energy density batteries -- high‐voltage spinel cathodes; Materials science -- Periodicals; 620.11
• DOI: 10.1002/admi.202201600
• Languages: English
• ISSNs: 2196-7350

Abstract

Abstract: The high voltage LiNi0.5 Mn1.5 O4 (LNMO) spinel is one of the promising cathodes for the lithium‐ion batteries due to its high energy densities, good rate performance. However, its high operating potential (≈4.75 V) causes extensive oxidation of conventional carbonate electrolytes, resulting an unstable and thick cathode electrolyte interphase (CEI) layer with a large irreversible capacity and low coulombic efficiency. Herein, this work reports the formation of thin LiF stabilized interfaces on LNMO via electrochemical fluorination that significantly improves the cycling stability and enhanced the capacity. An electrochemically induced conformal LiF layer acts as a part of a robust CEI by reducing the leakage of electrons and allowing the conduction of Li ions through it. Because of the robust LiF stabilized CEI, LNMO delivers a discharge capacity of ≈148.5 and ≈117.1 mAh g −1 at 0.1 and 1 C rate, respectively. It exhibits excellent cyclability with 80% capacity retention (CR) after 600 cycles in lithium‐half cell and ≈90% CR after 200 cycles in full cell with only 0.03% and 0.05% capacity decay per cycle in conventional carbonate electrolytes without additives. Such an excellent electrochemical performance could lead to the potential development of high energy density batteries with high voltage cathodes for grid‐based applications. Abstract : The electrochemical fluorination induced conformal LiF layer on LiNi0.5 Mn1.5 O4 cathode results in robust cathode electrolyte interphase, leading to excellent cyclability with 80% and 90% capacity retention after 600 and 200 cycles in half and full cell configuration, respectively. Besides this, cost‐effective and free from all the hazards associated with state‐of‐the‐art fluorination ensure its easy industrial upscaling.