Hydrangea-like NiCo2O4 enable fast lithium ions transportation for high-performance reduced graphene oxide-based freestanding lithium-sulfur battery cathode

To achieve high energy and power density in lithium-sulfur (Li-S) batteries, particular attention must be paid to the cathode side, specifically the sulfur content, cathode loading, and capacity within limited electrolyte conditions. In this study, hydrangea-like NiCo₂O₄ micro-particles are employed as structure element to create internal gaps within the reduced graphene oxide (rGO) matrix loaded with sulfur nanoparticles (Snp), facilitating the movement of lithium ions (Li⁺) and enhancing sulfur discharge reactions. This innovative cathode delivers a specific capacity of 1550 mAh g⁻¹ at 0.1 C (1 C = 1675 mAh g⁻¹) and 896 mAh g⁻¹ at 1 C, with a maximum sulfur content of 70 % within the cathode. The Snp@rGO/15NiCo₂O₄ electrode exhibits excellent cycling stability, maintaining 500 cycles at 1C and 900 cycles at 1.5 C, with only 0.08 % and 0.056 % capacity decay per cycle, respectively. These findings offer valuable insights for enhancing Li-S battery performance by opening the internal structure of the electrode with additional materials.