Abstract: An electrochemical device includes a transition metal oxide cathode, such as LiNi0.8Co0.1Mn0.1O2, and an electrolyte. The electrolyte includes N, N-dimethyltrifluoromethane-sulfonamide (DMTMSA) and lithium bis(fluorosulfonyl)imide (LiFSI). The DMTMSA and LiFSI may be either the primary component of the electrolyte or an additive in the electrolyte. The electrochemical device may also include a graphite anode or a lithium metal anode. With a lithium metal anode, the electrochemical device has an initial specific capacity of at least 231 mAh g?1. Over at least 100 cycles (upper cut-off voltage of 4.7±0.05 V vs. Li/Li+), the electrochemical device maintains an average specific capacity of at least 88% of the initial specific capacity and an average Coulombic efficiency of at least about 99.65%.

Abstract: An interlayer for a lithium-sulfur (Li—S) battery may include a separator coated with an intercalation compound. The intercalation compound may intrinsically exhibit and/or be modified to have a higher affinity for lithium polysulfides (LiPS), thus reducing the global sulfur mobility and the shuttling effect. Additionally, the intercalation compound may also reduce the formation of a Li2S clogging layer, which thus increases the battery lifetime by reducing active material loss and maintaining the rate performance of the Li—S battery. Unlike conventional inactive interlayer materials, the intercalation compound may also contribute to the capacity of the battery, thereby increasing the volumetric and gravimetric energy densities. In one example, an interlayer for the Li—S battery may be disposed between a cathode and an anode and may include a separator and a coating disposed on the separator. The coating may include an intercalation compound, such as Chevrel-phase Mo6S8, to reduce the global sulfur mobility.

Abstract: A hybrid cathode for a Li—S battery may include an intercalation-type material and a conversion-type material. The conversion-type material, such as sulfur, may increase the gravimetric energy density, Eg, of the battery. The intercalation-type material may increase the electrical and ionic conductivity of the cathode and contribute to the capacity of the battery, enabling replacement of partial high-surface-area conductive carbon and increasing the volumetric energy density, Ev. In combination, the conversion-type material and the intercalation-type material may be used to increase Eg and Ev simultaneously while providing sufficient rate capability. In one example, a hybrid cathode includes an electrode and a cathode material. The cathode material includes a first concentration of an intercalation compound, a second concentration of sulfur, and a third concentration of carbon. Furthermore, the intercalation compound and sulfur contribute to the capacity of the Li—S battery within a voltage window of 1.

Abstract: An interlayer for a lithium-sulfur (Li—S) battery may include a separator coated with an intercalation compound. The intercalation compound may intrinsically exhibit and/or be modified to have a higher affinity for lithium polysulfides (LiPS), thus reducing the global sulfur mobility and the shuttling effect. Additionally, the intercalation compound may also reduce the formation of a Li2S clogging layer, which thus increases the battery lifetime by reducing active material loss and maintaining the rate performance of the Li—S battery. Unlike conventional inactive interlayer materials, the intercalation compound may also contribute to the capacity of the battery, thereby increasing the volumetric and gravimetric energy densities. In one example, an interlayer for the Li—S battery may be disposed between a cathode and an anode and may include a separator and a coating disposed on the separator. The coating may include an intercalation compound, such as Chevrel-phase Mo6S8, to reduce the global sulfur mobility.