Silicon battery technology and solid state electrolytes are two areas of particular interest to provide safer batteries with higher energy densities, and there are many companies and research labs wokring on both.
The team at the US Army Research Laboratory and the University of Maryland have used a solid electrolyte to address some of the challenges of silicon battery cell design and provide a longer lifetime with higher energy density.
"We are very excited to demonstrate a new electrolyte design for lithium ion batteries that improves anode capacity by more than five times compared to traditional methods," said Army scientist Dr. Oleg Borodin. "This is the next step needed to move this technology closer to commercialization."
The team designed a self-healing, protective layer in the battery that significantly slows down the electrolyte and silicon anode degradation process which could extend the lifespan of next generation lithium-ion batteries.
Their latest battery design increased the number of possible cycles from tens to over a hundred with little degradation and was published in Nature Energy.
Anodes made out of silicon can offer about 1,500 to 2,800 mAh/g, four times as much capacity as the graphite anodes used in today’s lithium ion cells.
Silicon expands and contracts during a battery's operation, and as the silicon nanoparticles within the anode get larger, they often crack the protective layer -- called the solid electrolyte interphase -- that surrounds the anode.
The solid electrolyte interphase forms naturally when anode particles make direct contact with the electrolyte. The resulting barrier prevents further reactions from occurring and separates the anode from the electrolyte. But when this protective layer becomes damaged, the newly exposed anode particles will react continuously with electrolyte until it runs out.
"Others have tried to tackle this problem by designing a protective layer that expands when the silicon anode does," Borodin