The performances of the batteries need to be more and more improved to reach the requirements of applications like electric cars or energy storage. The new generation of batteries needs to store more energy and to charge faster with a price always reduced. Lithium-sulfur batteries are an interesting alternative to conventional batteries due to the theoretical high gravimetric capacity of sulfur and its cheap price. Nevertheless, sulfur has the drawback of being a poor conductor. For that reason, a large quantity of carbon black has to be added to obtain sufficient conductivity. This reduces considerably the quantity of sulfur that can be put in the battery. Composite powders of sulfur and carbon are seen as a solution to this problem, combining the high energy density of the sulfur with the good conductivity of the carbon black in a single material. Such materials are however challenging to handle for electrode production, especially with the upcoming dry-processes.

In this work, we present an investigation of the powder bulk properties of sulfur/carbon composite. Their flow and packing behaviors were investigated with tapped density (GranuPack, Granutools) and rotating drum methods (GranuDrum, Granutools). The composite powders were compared with reference powders made of sulfur and carbon black dry mixed with the same proportions as the composite powders. Differences in powder bulk density were observed and correlated to significant differences in battery capacity. Differences in powder flowability were also measured and assess differences in processability for electrode manufacturing. With the rise of dry processes, this study gives insight into the possibilities given by powder characterization for electrode manufacturing improvement.