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Abstract With the increasing demand for developing large‐energy‐density and safe batteries, a reliable lithium metal as an anode becomes more and more important in various lithium metal and solid‐state batteries. On the basis of better lithium regulation from MXene, a lithiophilic lithium metal surface is designed by introducing a 2D hybrid coating that consists of a thin covalent organic framework (COF‐1) modified MXene layer (denoted as COF‐MXene‐Li). The abundant lithiophilic boroxine sites on 2D COF‐1 attract lithium ions while the MXene further regulates lithium homogeneous nucleation and growth, thus preventing dendrite formation. The coin cell battery paired with LiNi0.8Mn0.1Co0.1O2(NMC811) as cathode material displays 17% more capacity retention compared with pure lithium metal after 400 cycles at 0.5C.Over 81.4% capacity retention along with 99.96% Coulombic efficiency (CE) of a 1.0 Ah pouch cell versus LiNi0.8Co0.15Al0.05O2(NCA) after 250 cycles is received. The assembled 1.6 Ah pouch cell with NMC811 show an energy density of up to 366.7 Wh Kg−1and an actual energy density based on the whole cell of up to 339.7 Wh Kg−1. The improved cycling stability particularly in pouch cells opens broad applications for this hybrid coating modified lithium metal as anode electrode in a variety of large‐energy‐density battery systems.
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A BF 3 ‐Doped MXene Dual‐Layer Interphase for a Reliable Lithium‐Metal Anode
Abstract A dual‐layer interphase that consists of an in‐situ‐formed lithium carboxylate organic layer and a thin BF3‐doped monolayer Ti3C2MXene on Li metal is reported. The honeycomb‐structured organic layer increases the wetting of electrolyte, leading to a thin solid electrolyte interface (SEI). While the BF3‐doped monolayer MXene provides abundant active sites for lithium homogeneous nucleation and growth, resulting in about 50% reduced thickness of inorganic‐rich components among the SEI layer. A low overpotential of less than 30 mV over 1000 h cycling in symmetric cells is received. The functional BF3 groups, along with the excellent electronic conductivity and smooth surface of the MXene, greatly reduce the lithium plating/stripping energy barrier, enabling a dendrite‐free lithium‐metal anode. The battery with this dual‐layer coated lithium metal as the anode displays greatly improved electrochemical performance. A high capacity‐retention of 175.4 mAh g−1at 1.0 C is achieved after 350 cycles. In a pouch cell with a capacity of 475 mAh, the battery still exhibits a high discharge capacity of 165.6 mAh g−1with a capacity retention of 90.2% after 200 cycles. In contrast to the fast capacity decay of pure Li metal, the battery using NCA as the cathode also displays excellent capacity retention in both coin and pouch cells. The dual‐layer modified surface provides an effective approach in stabilizing the Li‐metal anode.
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- Award ID(s):
- 2013525
- PAR ID:
- 10387833
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Materials
- Volume:
- 35
- Issue:
- 8
- ISSN:
- 0935-9648
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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