Most existing lithium-ion batteries (LIBs) integrate graphite anodes, which have a capacity of approximately 350 milliamp hours (mAh) per gram. The capacity of silicon anodes is almost 10 times higher than that of their graphite counterparts (around 2,800 mAh per gram), and could thus theoretically enable the development of more compact and lighter lithium-based batteries.

Despite their higher capacity, silicon anodes have so far been unable to compete with graphite anodes, as silicon expands and contracts during battery operation, so the anodes’ outer protective layer can easily crack while a battery is operating. In a recent paper published in Nature Energy, a team of researchers at the University of Maryland College Park and Army Research Laboratory has reported a new electrolyte design that could overcome the limitations of existing silicon anodes.

“Silicon anodes and their formed solid electrolyte interphase (SEI) protecting layers are easier to pulverize during battery operation, because the SEI strongly bonds to Si, so both experience a large volume of changes,” Ji Chen, one of the leading researchers who carried out the study, told Phys.org.