Core‐Shell Architectured Sulfur Coated α‐Fe2O3 Nano‐Sheet Anode for Li‐Ion Battery with Insitu Active Solid Electrolyte Interfacial Layer and Li‐Sulfur Energy Storage Systems

Elegant Active Li₂SO₄ Solid Electrolyte Interface!! A fused interlayer bonded sulfur coating on α-Fe₂O₃ nanosheets achieved throughmicrowave technique exhibits significant enhancements of lithium-ion redox kinetics in LIB as well as LISB. Self-induced Li₂SO₄ based active SEI interfacial layer protects the electrode surface from unwanted reactions of electrolyte components and promotes hassle-free lithium-ion mobility across the interface. Sulfur coated α-Fe₂O₃ electrode offers volume control over redox reactions and facilitates Li⁺ ion migration among the α-Fe₂O₃ nano-particulates. This contributes good C-rate capability with long cycle life and high endurance in powering of blue LED, which open up a new avenue to developing a next generation safety free solid-state Li-Sulfur mobility.

Abstract

A versatile approach is achieved through the surface coating of sulfur on α-Fe₂O₃ nanosheet by microwave treatment that inherently supports the formation of self-induced active solid electrolyte interface (SEI) layer which effectively protects the electrode surface and enhances the cyclic stability of lithium-ion battery. The present findings on a sulfur-coated α-Fe₂O₃@S-2 core-shell structured anode demonstrates an initial specific capacity of 1194 mAh g⁻¹ at a 0.1 C rate, and an average discharge capacity of 518 mAh g⁻¹ over 20 cycles. Sulfur coating proves the incredible development of an active SEI layer that prevents electrolyte decomposition and the electrode persuades with stable capacity, fast rate capability and retains excellent coulombic efficiency for 500 cycles in LIB. GITT measurements exhibit superior Li⁺ ion diffusion coefficient 2.87×10⁻¹⁰ cm² s⁻¹ at 80 % SOC for the α-Fe₂O₃@S-2 electrode. The in-depth ex-situ evaluations uncovered a fascinating self-assembled active Li₂SO₄ electrode-electrolyte interface formation in the sulfur-coated α-Fe₂O₃ electrode that contributes interfacial kinetics. The sulfur coated α-Fe₂O₃ electrode exhibits an exceptional high-rate performance and coulombic efficiency even in lithium-sulfur battery. This research overthrows sulfur‘s significance in forming an active interfacial bridging SEI layer that facilitates lithium-ion kinetics across the interface and alleviates undesirable SEI development.

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