Lithium ion sulfur with polymer membrane safe enough for future car batteries with improved 750 to 2700 Wh/kg energy density but still need longer life cycle

Greencarcongress reports researchers added a polysulfide to the polymer membranes during their synthesis with the aim to reduce the cathode dissolution during operation. To improve the room-temperature ionic conductivity of the polymer electrolyte, they plasticized the LiS8 added membrane.

The resulting LixSn-C/GPS-Li2S8/S-C lithium-ion sulfur cell is characterized by a high safety level, due to the polymer configuration and the absence of lithium metal anode, and expected low cost. At the lower C-rate, the cell may stably deliver a capacity of about 1500 mAh gS−1 at an average voltage of 1.8 V, while at the higher C-rate, the cell delivers a still relevant capacity of about 500 mAh gS−1 at an average voltage of 1.5 V, hence with a theoretical energy density ranging from 2700Wh/kg to 750 Wh/kg, respectively.

Longer cycle life and further characterizations are certainly required to match the severe targets of the lithium battery community.

Nature Scientific Reports – A lithium-ion sulfur battery using a polymer, polysulfide-added membrane

Researchers report the performances of a lithium-ion sulfur battery characterized by a polymer configuration. The cell, based on a sulfur-carbon cathode, a Li-Sn-C nanostructured anode and a PEO-based, polysulfide-added electrolyte, shows very good electrochemical performances in terms of stability and delivered capacity. The remarkable cell performances are ascribed to the mitigation of the cathode dissolution process due to the buffer action ensured by the polysulfide added to the polymer electrolyte. This electrolyte configuration allows the achievement of a stable capacity ranging from 500 to 1500 mAh gS-1, depending on the cycling rate. The use of a polymer electrolyte and the replacement of the lithium metal with a Li-Sn-C nanostructured alloy are expected to guarantee high safety content, thus suggesting the battery here studied as advanced energy storage system.

SOURCES – Greencarcongress, Nature Scientific Reports