The dual actions of modified polybenzimidazole in taming the polysulfide shuttle for long-life lithium–sulfur batteries

摘要

Researchers have used a super-stable polymer to block adverse dissolution effects in energy-rich rechargeable lithium-sulfur batteries. Polybenzimidazole (PBI) polymers find use in firefighting equipment and astronaut spacesuits because of their high mechanical and thermal stability. Research team led by Shanqing Zhang from Griffith Universityin Australia and Zhoupeng Li from Zhejiang University in China now shows that PBI can make an attractive binder and separating agent for next-generation batteries. While the lithium-sulfur system has higher energy density than current lithium-ion batteries, polysulfides shuttling effect, the main technical barrier often degrades device efficiency. The team prepared a new electrode by mixing a sulfur-carbon composite with a modified form of PBI. They found battery durability improved by three to five times over typical polymer binders, while favorable binding interactions between PBI and polysulfides enhanced performance and cycling stability.