A new paper published in the Journal of The Electrochemical Society, “Mixed Conduction Membranes Suppress the Polysulfide Shuttle in Lithium-Sulfur Batteries,” describes a new battery membrane that makes the cycle life of lithium-sulfur batteries comparable to their lithium-ion counterparts.
The research, led by ECS Fellow Sri Narayan, offers a potential solution to one of the biggest barriers facing next generation batteries: how to create a tiny battery that packs a huge punch.
Narayan and Derek Moy, co-author of the paper, believe that lithium-sulfur batteries could be the answer.
The lithium-sulfur battery has been praised for its high energy storage capacity, but hast struggled in competing with the lithium-ion battery when it comes to cycle life. To put it in perspective, a lithium-sulfur battery can be charged between 50 and 100 times; a lithium-ion battery lasts upwards of 1,200 cycles.
To address this issue, the researchers devised the “Mixed Conduction Membrane” (MCM).
This from the University of Southern California:
[The MCM is] a small piece of non-porous, fabricated material sandwiched between two layers of porous separators, soaked in electrolytes and placed between the two electrodes.
“This advance removes one of the major technical barriers to the commercialization of the lithium-sulfur battery, allowing us to realize better options for energy efficiency,” says Narayan, a professor at the University of Southern California’s Dornsife College of Letters, Arts and Sciences. “We can now focus our efforts on improving other parts of lithium-sulfur battery discharge and recharge that hurt the overall life cycle of the battery.”
The membrane works as a barrier in reducing the shuttling of dissolved polysulfides between anode and cathode, a process that increases the kind of cycle strain that has made the use of lithium-sulfur batteries for energy storage a challenge. The MCM still allows for the necessary movement of lithium ions, mimicking the process as it occurs in lithium-ion batteries. This novel membrane solution preserves the high-discharge rate capability and energy density without losing capacity over time.
At various rates of discharge, the researchers found that the lithium-sulfur batteries that made use of MCM led to 100 percent capacity retention and had up to four times longer life compared to batteries without the membrane.
