Super Selective Separators for Battery Applications

Rechargeable Lithium-sulfur (Li-S) batteries, with a theoretical energy density 5 times that of Lithium-ion batteries (LiBs), exhibit great potential as a low-cost, sustainable, and high-energy density alternative to the current state-of-the-art LiBs. However, serious problems due to polysulfide shuttling and Li dendrites formation have deteriorated the capacity retention and rate cyclability of Li-S batteries. Using highly efficient separators in Li-S batteries can be a solution to these issues. The 3S Battery project (Super Selective Separator for Battery Applications) aims at developing highly efficient separators with nanostructures and desired functions based on transport mechanisms. The defined separator should act as a selective channel that effectively suppresses the polysulfides migrating while facilitating the Li+ ion transport with uniform distribution, thereby solving the problems caused by both polysulfide shuttling and dendrite formation. Functional coatings will also reactivate the trapped sulfur to increase cathode efficiency. In this project, separators with the proposed designs will be developed, their performances in Li-S batteries will be evaluated, and the separators' fabrication and upscaling potential will be considered during the development. At the end of the project, the developed separators are expected to enable Li-S batteries to achieve high performance as indicated by the key performance indicators (KPI), including high cycle stability of >2,000 cycles, corresponding to a capacity decay of ~0.01% per cycle, with an initial discharge capacity of ~1300 mA?h g-1 at a 0.1 C. The separators should also be adopted for use in other types of metal sulfur batteries for their high selectivity or LiBs for their reduced dendrite formation The project implementation is based on highly interdisciplinary collaboration between experts at NTNU and SINTEF in nanomaterials, membranes, and batteries. Uppsala University is an international partner.

Rechargeable Lithium-sulfur (Li-S) batteries have a theoretic energy density 5 times that of Lithium-ion batteries (LiBs), showing great potential as a low-cost, sustainable, and high-energy density alternative to the current state-of-the-art LiBs. However, serious problems due to polysulfide shuttling and Li dendrites formation have deteriorated the capacity retention and rate cyclability of Li-S batteries. The 3S Battery project (Super Selective Separator for Battery Applications) is proposed to mitigate these challenges, aiming at developing highly efficient separators for Li-S battery applications. The defined separator should act as a selective channel that effectively suppresses the polysulfides migrating while facilitating the Li+ ion transport with uniform distribution, thereby solving the problems caused by both polysulfide shuttling and dendrite formation. Functional coatings will also reactivate the trapped sulfur to increase cathode efficiency. 3S Battery project will design nanomaterials for the desired functions of Li-S battery separators, then fabricate separators using innovative membrane fabrication techniques, and evaluate the battery performance. The project implementation is based on highly interdisciplinary collaboration between experts at NTNU and SINTEF in nanomaterials, membranes, and batteries. The developed separators are expected to enable Li-S batteries to achieve high performance as indicated by the key performance indicators (KPI), including high cycle stability of >2,000 cycles, corresponding to a capacity decay of ~0.01% per cycle, with an initial discharge capacity of ~1300 mA?h g-1 at a 0.1 C. This performance will be revolutionary and attract industry interest. Responsible Research and Innovation (RRI) aspects will be included to identify the risks and opportunities stemming from the developed separators. Education and training of competent engineers, especially in battery technology, is also an important part of the project.