Li/S battery has recently been recognized as the new generation battery technology. Unfortunately, many challenging issues have slowed down its progress to commercialization. These obstacles essentially include, but are not limited to, the instability of the sulfur cathode and the dendritic interface of the lithium anode.
This talk will spread to the three selected aspects associated with Li/S cell: cathode materials, interlayer and full cell design. Various sulfur-based composites with a secondary phase of carbons, polymers, oxides, sulfides or carbides have been developed as advanced cathode materials for Li/S batteries. We will introduce the synthesis and properties of solid-state organic polysulfides as alternative cathodes for Li/S batteries. The capping moieties in the organic polysulfides not only introduced redox activity, but also acted as polysulfide ‘fishing’ spots to mitigate the polysulfide leaking problem.
Aside from the cathode materials, the interlayer plays a critical role in regulating the ionic flux and maintaining a healthy cell condition for durable device performance. We will share the recent discovery of the electrochemical glassification of metal-organic frameworks in the presence of polysulfides, and interpret the operating mechanism of MOF interlayer from a different structure point of view.
Bringing all optimal battery components (electrode, electrolyte, separator, interlayer, etc.) to enable working full cell is the ‘Holy Grail’ of Li/S battery research. A strategy of parallel solid-liquid interface engineering will be introduced for the design of Li/S full cell. The improvement of sulfur utilization and the suppression of sulfur exhaust and dendrite growth were simultaneously achieved via modifying the composition and surface homogeneity of the anode and cathode of the full cell.