Electrocatalytic NiCo₂O₄ Nanofiber Arrays on Carbon Cloth for Flexible and High-Loading Lithium–Sulfur Batteries

Abstract

Lithium-sulfur batteries have ultrahigh theoretical energy densities, which makes them one of the most promising next-generation energy storage systems. However, it is still difficult to achieve large-scale commercialization because of the severe lithium polysulfide (LiPS) shuttle effect and low sulfur loading. Here, we report a flexible lithium-sulfur battery of a high sulfur loading with the assistance of NiCo₂O₄ nanofiber array grown carbon cloth. The NiCo₂O₄ nanofibers are ideal electrocatalysts for accelerating LiPS conversion kinetics through strong chemical interactions. Therefore, the composite cathode delivers a high specific capacity of 1280 mAh g^-1 at 0.2 C with a sulfur loading of 3.5 mg cm^-2, and it can maintain a high specific capacity of 660 mAh g^-1 after 200 cycles, showing a good cycle stability. The "layer-by-layer" stacking strategy enables the Li-S battery with a high S loading of ∼9.0 mg cm^-2 to deliver a high areal capacity of 8.9 mAh cm^-2.