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A D V A N C E D M A T E R I A L S & P R O C E S S E S | O C T O B E R 2 0 2 1 8 Using lithium metal in place of graph- ite as the anode material can increase the battery’s energy storage capacity, but, over time, the lithium foil tends to form needle-like dendrites. These tiny metal particles can pierce the separa- tor and cause a short circuit, explain researchers. “Dendrite growth on the elec- trodes and unstable solid-electrolyte interphase formation have created safety concerns in lithium-ion batteries and hindered practical applications,” researcher Yue Zhou said. In previous funded research, Zhouusedplasmapro- cessing to apply an additional coating to protect the lithium metal anode and thereby prevent dendrite formation. Doctoral student Jyotshna Pokharel assembles a lithium-ion battery in which lithiummetal is used in place of graphite as the anode material. Courtesy SDSU. In addition, he combined graphite and silicon oxide to make an ultrathin film that prevents dendrite growth and en- hances ion transport. This also creates an artificial interfacial layer between the electrolyte and the lithium metal electrode that increases stability and improves battery cell performance. “How the protective layer interacts with the elec- trochemical process of the lithium metal anode is not well understood,” Zhou says. “We want to understand the physical and chemical properties that lead to these desirable properties.” What the researchers learn will help im- prove the safety of electric vehicles and advance efforts to develop devic- es that can store renewable energy. sdstate.edu, utexas.edu.