Abstract: High energy density cathode materials, such as LiNiXMnYCoZO2 (NMC) cathode materials, with improved discharge capacity (hence energy density) and enhanced cycle life are described. A solid electrolyte, such as lithium phosphate infused inside of secondary particles of the cathode material demonstrates significantly enhanced structural integrity without significant or without any observable particle cracking occurring during charge/discharge processes, showing high capacity retention of more than 90% after 200 cycles at room temperature. In certain embodiments the disclosed cathode materials (and cathodes made therefrom) are formed using nickel-rich NMC and/or are used in a battery system with a non-aqueous dual-Li salt electrolytes.

Abstract: Low flammability and nonflammable localized superconcentrated electrolytes (LSEs) for stable operation of electrochemical devices, such as rechargeable batteries, supercapacitors, and sensors, are disclosed. Electrochemical devices, such as rechargeable batteries, supercapacitors, and sensors, including the low flammability and nonflammable LSEs are also disclosed. The low flammability and nonflammable LSEs include an active salt, a solvent comprising a flame retardant compound, wherein the active salt is soluble in the solvent, and a diluent in which the active salt is insoluble or poorly soluble. In certain embodiments, such as when the solvent and diluent are immiscible, the LSE further includes a bridge solvent.

Abstract: Embodiments of localized superconcentrated electrolytes (LSEs) for stable operation of electrochemical devices, such as rechargeable batteries, supercapacitors, and sensors, are disclosed. Electrochemical devices, such as rechargeable batteries, supercapacitors, and sensors, including the LSEs are also disclosed. The LSEs include an active salt, a solvent in which the active salt is soluble, and a diluent in which the active salt is insoluble or poorly soluble. In certain embodiments, such as when the solvent and diluent are immiscible, the LSE further includes a bridge solvent.

Abstract: Embodiments provide a hybrid supercapacitor exhibiting high energy and power densities enabled by a high-performance lithium-alloy anode coupled with a porous carbon cathode in an electrolyte containing lithium salt. Embodiments include a size reduced silicon oxide anode, a boron-doped silicon oxide anode, and/or a carbon coated silicon oxide anode, which may improve cycling stability and rate performance. Further embodiments include a hybrid supercapacitor system using a Li-active anode in an electrolyte including LiPF6 in a mixture of ethylene carbonate, diethyl carbonate, and dimethyl carbonate (EC:DEC:DMC, 2:1:2 by vol.) and 10 wt % fluoroethylene carbonate (FEC), which may reduce the self-discharge rate.

Abstract: High energy density cathode materials, such as LiNixMnyCozO2 (NMC) cathode materials, with improved discharge capacity (hence energy density) and enhanced cycle life are described, A solid electrolyte, such as lithium phosphate infused inside of secondary particles of the cathode material demonstrates significantly enhanced structural integrity without significant or without any observable particle cracking occurring during charge/discharge processes, showing high capacity retention of more than 90% after 200 cycles at room temperature. In certain embodiments the disclosed cathode materials (and cathodes made therefrom) are formed using nickel-rich NMC and/or are used in a battery system with a non-aqueous dual-Li salt electrolytes.

Abstract: Embodiments provide a hybrid supercapacitor exhibiting high energy and power densities enabled by a high-performance lithium-alloy anode coupled with a porous carbon cathode in an electrolyte containing lithium salt. Embodiments include a size reduced silicon oxide anode, a boron-doped silicon oxide anode, and/or a carbon coated silicon oxide anode, which may improve cycling stability and rate performance. Further embodiments include a hybrid supercapacitor system using a Li-active anode in an electrolyte including LiPF6 in a mixture of ethylene carbonate, diethyl carbonate, and dimethyl carbonate (EC:DEC:DMC, 2:1:2 by vol.) and 10 wt % fluoroethylene carbonate (FEC), which may reduce the self-discharge rate.

Abstract: We provide a liquid electrolyte for a lithium-sulfur battery. Electrolytes of the invention may include a protecting additive; a lithium salt (in addition to LiNO3, if that is selected as the protecting additive); at least one electrolyte solvent; and a dissolved electrochemically active material comprising sulfur. In one embodiment an electrolyte includes 0.1-2 M of one or more of LiPF6, LiBF4, LiAsF6, LiClO4, LiCF3SO3, LiN(CF3SO2)2, 0.1-1 M LiNO3, at least one nonaqueous solvent; and dissolved electrochemically active material comprising sulfur in the form of at least one of a soluble lithium polysulfide and/or organodisulfide compounds, which is used in a lithium-sulfur cell and a battery having a plurality of lithium-sulfur cells.