Low-temperature one-step solid state chemical synthesis of GaN nanosheets for conquering polysulfides in Li–S battery

Abstract

Gallium nitride (GaN) nanosheets have been prepared as an active material for conquering polysulfides in Lithium–Sulfur (Li–S) batteries via one simple synthetic route at 550 °C. The process was carried out in a stainless steel autoclave by using gallium nitrate hydrate, sodium amide and metallic lithium as starting materials. The product was proven to be hexagonal GaN nanosheets by combined X-ray powder diffraction (XRD) pattern and Scanning electron microscopy (SEM). The GaN nanosheets were then used to coat on the Li–S battery separator, and the result proves an effective inhibition of the shutting problem and gives excellent electrochemical properties compared with traditional separators or GaN additives. The battery assembled by GaN coated separator shows good cycling stability with 408 mAh/g and a low capacity fading of 0.6‰ per cycle from 11th to 480th cycle at 2 C due to high utilization of the sulfur-based active species.