Cover Image, Volume 5, Number 3, March 2023

Abstract

Front cover image: Lithium metal battery matched with high nickel cathode is a promising energy storage scheme. However, developing an electrolyte that can simultaneously match the robust oxidizing cathode and the reducing lithium metal anode is challenging. In article number https://doi.org/10.1002/cey2.275, Yang et al. developed a new high‐concentration ternary lithium salt ether‐based electrolyte to make commercial high‐mass loading high‐nickel NMC (LiNi0.6Co0.2Mn0.2O2) cathode and thin anode lithium metal battery stable cycling at 4.5V. The optimization mechanism is analyzed from solvent sheath structure, solid electrolyte interface (SEI), and cathode lattice transition. This work provides new insight into high‐voltage lithium metal battery electrolyte.

High‐Energy‐Density Lithium Metal Batteries with Impressive Li+ Transport Dynamic and Wide‐Temperature Performance from −60 to 60 °C

“…[ 32,33 ] It is worth noting that the CEI formed in 2.4m‐DEF is mainly the decomposition products of DFOB − anion and FEC, such as BO (192 eV in B 1s)/BF (193.9 eV in B 1s), LiF, CO, and OCO (Figure 7c; Figure S17, Supporting Information). [ 34 ] The LiF signal strength is weaker than that of commercial electrolyte, which can be ascribed to less HF generation in 2.4m‐DEF. These XPS results furtherly demonstrate a stable CEI layer formed by the decomposition of DFOB − and FEC which can effectively stabilize NCM90 cathode/electrolyte interface and improve battery performance.…”

Critical Review of Fluorinated Electrolytes for High‐Performance Lithium Metal Batteries

“…A ternary-salt electrolyte consisting of LiTFSI/ LiDFOB/ LiBF 4 in DME with 5% FEC was designed by Yang et al to address the issue of the vulnerability of ether under high-voltage. Thin and stable LiF, Li 3 N-rich SEI and Li 2 SO 3 -rich CEI were obtained in the LMBs, resulting in enhanced cycling stability of NCM622||Li cells with capacity retentions of 80% after 430 cycles at cut-off voltage of 4.4 V and 83% after 100 cycles at high cut-off voltage of 4.5 V. [123] Meanwhile, Liu et al developed a ternary-salt electrolyte composed of LiTFSI-LiPF 6 -LiFSI salts and poly (1,3-dioxolane) (PDOL) by in-situ polymerization. The Li||Li symmetrical cells based on the ternary-salt system exhibited an overpotential of ≈12 mV after 1200 h at 0.5 mA cm −2 with a capacity of 0.5 mA h cm −2 .…”

“…to address the issue of the vulnerability of ether under high‐voltage. Thin and stable LiF, Li 3 N‐rich SEI and Li 2 SO 3 ‐rich CEI were obtained in the LMBs, resulting in enhanced cycling stability of NCM622||Li cells with capacity retentions of 80% after 430 cycles at cut‐off voltage of 4.4 V and 83% after 100 cycles at high cut‐off voltage of 4.5 V. [ 123 ] Meanwhile, Liu et al. developed a ternary‐salt electrolyte composed of LiTFSI‐LiPF 6 ‐LiFSI salts and poly (1,3‐dioxolane) (PDOL) by in‐situ polymerization.…”