Electrocatalytic Barrier Comprising Polar SnO2 Quantum Dots Anchored Within Porous Carbon Microspheres Prepared by Spray Drying Process for Li–S Batteries

Abstract

Hypothesis: Porous carbon microspheres (PCMs) with embedded tin di‐oxide (SnO2) quantum dots (QDs) (P‐SnO2@PCMs) are synthesized and employed as polysulfide barriers to enrich the electrochemical properties.Experiments: This composite structure is prepared by spray drying procedure and followed by heat‐treatment, resulting in well‐arranged macropores with a diameter of 59 nm generated by the polystyrene (PS) nanobeads (ϕ = 150 nm) decomposition. P‐SnO2@PCMs is functioned as an electrocatalytic interlayer and offer advantages such as reduced diffusion length for charged particles that guarantees immediate transfer, improved electrode wetting due to efficient electrolyte infiltration, and accommodation of large volume fluctuations during the redox reactions. Furthermore, the incorporation of polar SnO2 QDs within the microspheres allows for efficient chemical confinement and alteration of trapped polysulfide species due to catalytic activity, leading to an extensive use of the active material.Findings: Advancing from the nanostructural eminence, lithium–sulfur (Li–S) cells paired with P‐SnO2@PCMs‐coated separator and conventional sulfur electrode showed outstanding rate performance (321 mA h g−1 at 2.0 C) and prolonged cyclic steadiness at 0.1 C. This innovative synthesis strategy provides valuable insights for developing novel nanostructures applicable to various rechargeable devices.