Localized nitride strategy to construct interfacial and electronic modulated WO3/WN nanoparticles for superior lithium-ion storage.

The interfacial effect is important for the tungsten trioxide (WO3)-based anode to achieve superior lithium-ion storage performance. Herein, the interfacial effect was constructed by in-situ surface direct nitridation reaction at 600 â„ƒ for 30 min of the as-synthesis WO3 nanoparticles (WO3/WN). X-ray photoelectron spectroscopy (XPS) analysis confirms evident chemical interaction between WO3 and WN via the interfacial covalent bond (WON). This WO3/WN anode shows a distinct interfacial effect for an efficient interatomic electron migration. Electrochemical kinetic analysis shows enhanced pseudocapacitance contribution. The galvanostatic intermittent titration technique (GITT) result demonstrates improved charge transfer kinetics. Ex-situ X-ray diffraction (XRD) analysis reveals the reversible oxidation and reduction reaction of the WO3/WN anode. The density functional theory (DFT) result shows that the evident interfacial bonding effect can enhance the electrochemical reaction kinetics of the WO3/WN anode. The discharge capacity can reach up to 546.9 mA h g-1 at 0.1 A g-1 after 200 cycles. After 2000 cycles, the capacity retention is approximately 85.97 % at 1.0 A g-1. In addition, the WO3/WN full cell (LiFePO4/C//WO3/WN) demonstrates excellent rate capability and capacity retention ratio. This in-situ surface nitridation strategy is an effective solution for designing an oxide-based anode with good electrochemical performance and beyond.

In Situ Hybridization Strategy Constructs Heterogeneous Interfaces to Form Electronically Modulated MoS2/FeS2 as the Anode for High-Performance Lithium-Ion Storage.

The interfacial effect is important for anodes of transition metal dichalcogenides (TMDs) to achieve superior lithium-ion storage performance. In this paper, a MoS2/FeS2 heterojunction is synthesized by a simple hydrothermal reaction to construct the interface effect, and the heterostructure introduces an inherent electric field that accelerates the de-embedding process of lithium ions, improves the electron transfer capability, and effectively mitigates volume expansion. XPS analysis confirms evident chemical interaction between MoS2 and FeS2 via an interfacial covalent bond (Mo-S-Fe). This MoS2/FeS2 anode shows a distinct interfacial effect for efficient interatomic electron migration. The electrochemical performance demonstrated that the discharge capacity can reach up to 1217.8 mA h g-1 at 0.1 A g-1 after 200 cycles, with a capacity retention rate of 72.9%. After 2000 cycles, the capacity retention is about 61.6% at 1.0 A g-1, and the discharge capacity can still reach 638.9 mA h g-1. Electrochemical kinetic analysis indicated an enhanced pseudocapacitance contribution and that the MoS2/FeS2 had sufficient adsorption of lithium ions. This paper therefore argues that this interfacial engineering is an effective solution for designing sulfide-based anodes with good electrochemical properties.

Pre-lithiation strategy to design a high-performance zinc oxide anode for lithium-ion batteries.

Zinc oxide (ZnO) shows great potential as an anode material for advanced energy storage devices owing to its good structural stability and low cost. However, its inferior cycling capacity seriously restricts its practical application. In this work, a pre-lithiation strategy is adopted to construct pre-lithiated ZnO (Li-ZnO) via the facile solid-state reaction method. This well-designed Li-ZnO is polycrystalline, consisting of fine particles. XPS analysis and Raman results confirm the successful pre-lithiation strategy. The pre-lithiation strategy increases the electronic conductivity of Li-ZnO without further carbon coating and suppresses the volume expansion during the electrochemical reaction. As a result, 5 mol% Li-ZnO displays good reversible capacity with a specific capacity of 639 mA h g-1 after 200 cycles at 0.1 A g-1. After 1440 cycles at 1.0 A g-1, the capacity retention is 380 mA h g-1. The pseudocapacitance contribution can reach up to 72.5% at 1.0 mV s-1. Electrochemical kinetic analysis shows that this pre-lithiation strategy can accelerate the lithium-ion diffusion and charge transfer kinetics of the Li-ZnO anode and suppress the pulverization of the electrochemical reaction. This study demonstrates the necessity of developing new anode materials with good cycling stability via this pre-lithiation strategy.

Influence Mechanism of Interfacial Oxidation of Li3YCl6 Solid Electrolyte on Reduction Potential.

Halide-based solid electrolytes are promising candidates for all solid-state lithium-ion batteries (ASSLBs) due to their high ionic conductivity, wide electrochemical window, and excellent chemical stability with cathode materials. However, when tested in practice, their intrinsic electrochemical stability windows do not well match the conditions for stable operation of ASSBs. Existing literature reports halide-based ASSBs that still operate well outside the electrochemical stability window, while ASSBs that do not operate within the window are not well studied or the studies are based on the cathode material interface. In this study, we aim to elucidate the mechanism behind all-solid-state battery failure by investigating how the reduction potential of Li3YCl6 solid-state electrolyte itself changes under overcharging conditions. Our findings demonstrate that in Li-In|Li3YCl6|Li3YCl6-C half-cells during the first state of charge, Cl ions participate in charge compensation, resulting in a depletion of ligands. This phenomenon significantly affects the reduction potential of Y3+, causing it to be reduced to Y2Cl3 and ultimately to Y0 at conditions far exceeding its actual reduction potential. Furthermore, we analyze the interfacial impedance induced by this process and propose a novel perspective on battery failure.

Heterointerface Engineered Core-Shell Fe2O3@TiO2 for High-Performance Lithium-Ion Storage.

The rational design of the heterogeneous interfaces enables precise adjustment of the electronic structure and optimization of the kinetics for electron/ion migration in energy storage materials. In this work, the built-in electric field is introduced to the iron-based anode material (Fe2O3@TiO2) through the well-designed heterostructure. This model serves as an ideal platform for comprehending the atomic-level optimization of electron transfer in advanced lithium-ion batteries (LIBs). As a result, the core-shell Fe2O3@TiO2 delivers a remarkable discharge capacity of 1342 mAh g-1 and an extraordinary capacity retention of 82.7% at 0.1 A g-1 after 300 cycles. Fe2O3@TiO2 shows an excellent rate performance from 0.1 A g-1 to 4.0 A g-1. Further, the discharge capacity of Fe2O3@TiO2 reached 736 mAh g-1 at 1.0 A g-1 after 2000 cycles, and the corresponding capacity retention is 83.62%. The heterostructure forms a conventional p-n junction, successfully constructing the built-in electric field and lithium-ion reservoir. The kinetic analysis demonstrates that Fe2O3@TiO2 displays high pseudocapacitance behavior (77.8%) and fast lithium-ion reaction kinetics. The capability of heterointerface engineering to optimize electrochemical reaction kinetics offers novel insights for constructing high-performance iron-based anodes for LIBs.