Facile synthesis of a high-entropy Oxide-Si nanocomposite via electrostatic spinning for lithium-ion battery electrodes

Abstract

High-entropy oxides (HEOs) have emerged as potential contenders in materials science because of their exceptional structural stability and superior ionic conductivity. Silicon (Si) produces a significant volume expansion effect when utilized as an anode component in lithium-ion batteries (LIBs), which restricts its use in high-energy density systems. To address this issue, our study innovatively adopts the electrospinning technique to meticulously design a composite system consisting of spinel-structured HEO(FeCoNiCrMn)₃O₄ and nanostructured Si, successfully fabricating a porous fibrous Si/HEO composite. In this composite, the HEO tightly and uniformly encapsulates the Si nanoparticles, effectively isolating the Si from direct exposure to the electrolyte while simultaneously constructing a nanoporous fibrous framework that markedly disperses the stresses generated during lithiation, thereby significantly enhancing the structural stability of the material. Furthermore, its stability mechanism was explained through Electron Localization Function (ELF) calculations. The experimental outcomes highlight the outstanding stability and effectiveness of the fabricated Si/HEO electrode. Upon exposure to a current density of 0.1 A g⁻¹, the electrode demonstrates a remarkable capacity retention of 1393.28 mAh g⁻¹ following 200 cycles. Therefore, the study aims to guide the design and production of lithium-ion battery electrode materials featuring novel silicon/HEO nanocomposites.