HIGH CAPACITY AND STABLE CATHODE MATERIALS
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.
HIGH CAPACITY AND STABLE CATHODE MATERIALS
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.
Methods and apparatuses for making cathodes for high-temperature, rechargeable batteries
The approaches for fabricating cathodes can be adapted to improve control over cathode composition and to better accommodate batteries of any shape and their assembly. For example, a first solid having an alkali metal halide, a second solid having a transition metal, and a third solid having an alkali metal aluminum halide are combined into a mixture. The mixture can be heated in a vacuum to a temperature that is greater than or equal to the melting point of the third solid. When the third solid is substantially molten liquid, the mixture is compressed into a desired cathode shape and then cooled to solidify the mixture in the desired cathode shape.
LOW FLAMMABILITY ELECTROLYTES FOR STABLE OPERATION OF LITHIUM AND SODIUM ION BATTERIES
This invention is related to Localized high concentration electrolytes (LHCE) that are stable with alkane metal anode, graphite anode, and various cathode materials in an electrochemical cell. LHCE electrolytes contain two parts of the solvents. First part of the solvent or solvent mixture (A) (such as carbonate solvents, ether solvents, or carbonate/ether solvent mixtures) has a high solvability for the active salt or salt mixture (S). When used separately, these high concentration electrolytes are stable with anode (such as lithium, sodium and graphite), cathode (including both ion intercalation and conversion compounds) and current collectors (such as Cu and Al) that are often unstable in the case of low concentration electrolytes. The second part of the solvent or solvent mixture (B) is miscible with the part A of the solvents used in the electrolytes, but has only a very low solvability of the active salt (S). Solvent B is also stable with anode (such as lithium, sodium and graphite), cathode (including both ion intercalation and conversion compounds) and current collectors (such as Cu and Al) even at low concentration conditions. When the active salt or salt mixture S is added to the solvent mixture consists of solvent A and B, salt S will preferentially coordinate with the solvent A and form a localized high concentration electrolyte which is stable with other part of the electrochemical cells, but the overall concentration of the electrolyte is still be low. The electrolyte containing localized high concentration salt consists of salt S, solvent A, and solvent B is not only stable with anode by forming high quality solid electrolyte interphase (SEI) layers, but also stable with high voltage cathodes, thereby improving long-term cycling stability of electrochemical cells. Furthermore, addition of solvent B effectively decreases the salt concentration (lowered cost), reduces the electrolyte viscosity and improves the ionic conductivity and wetting ability of the electrolyte. This invention could be widely applied to a variety of electrochemical systems, including lithium (Li) metal batteries, Li ion batteries, Li-S batteries, Li-O2 batteries, sodium metal and sodium ion batteries, magnesium ion batteries, aqueous Li batteries (such as dilution of concentrated LiTFSI/NaTFSI aqueous electrolyte), super capacitors, sensors.
Matthew Fayette
Matthew Fayette joined the staff at PNNL in 2019, where he is working on the development of Zinc-ion Battery materials.
LOCALIZED SUPERCONCENTRATED ELECTROLYTES FOR STABLE CYCLING OF ELECTROCHEMICAL DEVICES
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.
LOW FLAMMABILITY ELECTROLYTES FOR STABLE OPERATION OF ELECTROCHEMICAL DEVICES
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.
Research Hints at Double the Driving Range for Electric Vehicles
When it comes to the special sauce of batteries, PNNL researchers say it's all about the salt concentration.
A Model Catalyst
Three years ago, a multi-disciplinary PNNL team led by Laboratory Fellow Pete McGrail devised a method to produce magnesium metal from salts extracted from sea water and other brine solutions.
A Unique Coastal Forest Flooding Experiment
This study demonstrated that a large-scale flooding experiment in coastal Maryland, USA, aiming to understand how freshwater and saltwater floods may alter soil biogeochemical cycles and vegetation in a deciduous coastal forest.