Bingqing Wei Credit: University of DelawareResearchers at the University of Delaware have demonstrated a new polysulfide entrapping strategy that greatly improves the cycle stability of lithium sulfide (Li-S) batteries. This discovery could remove one of the barriers to developing batteries with greater energy density than lithium-ion (Li-ion) batteries.

The common Li-ion batteries that power many portable electronic devices lack sufficient energy density — the amount of energy stored in a physical space or mass — for use in smart grid and electric transportation applications. The energy density of Li-S is five times greater than Li-ion density. Li-S batteries also cost less to manufacture.

The downside of Li-S batteries is rapid capacity fade: the charge they deliver decreases sharply with use. The polysulfide shuttle effect, where sulfur spontaneously forms polysulfides, is the culprit.

Lead researcher Bingqing Wei demonstrated that adding ferroelectric nanoparticles to the battery’s cathode anchors the polysulfides and prevents them from causing the loss of active materials at the cathode. Wei says that Li-S battery manufacture can be seamlessly coupled to current industrial processes.