Abstract: Observed battery system values characterizing one or more states associated with the battery system over time may be received for a battery system associated with a device. A prospective control profile identifying a time-varying pattern of battery system charge and/or discharge for the designated device over time may be determined. Prospective perturbed control profiles introducing variation over time into the prospective control profile may be determined. Battery state estimate values and corresponding predicted battery state variance values may be determined for the designated battery system by applying a trained temporal convolutional neural network to the prospective perturbed control profiles and the observed battery system values. The predicted battery state variance values may indicate statistical uncertainty for the predicted battery state estimate values. A designated perturbed control profile may be selected based on the plurality of predicted battery state variance values.

Abstract: Observed battery system values may be received for one or more battery systems associated with one or more devices. The observed battery system values may characterize operation of the one or more battery systems over time. Prospective control profiles may be determined for the battery systems. The prospective control profiles may correspond to a time-varying patterns of battery system charge and/or discharge for prospective courses of action for the devices over time. Predicted battery system values may be determined for the battery systems by applying a trained temporal convolutional neural network to the prospective control profiles and the observed battery system values. A designated control profile may be selected based on the plurality of predicted battery system values. An instruction may be sent to a designated device to execute a course of action corresponding with the designated control profile.

Abstract: Control profiles may be determined for a designated type of battery system. The control profiles may define patterns of charging and/or discharging the designated type of battery system over time. Simulated battery values may be determined by applying one or more physics models to the control profiles. The physics models may model interactions between states. A pre-trained battery value temporal convolutional neural network may be determined based on a timeseries pre-training dataset that includes the control profiles and the simulated battery values. One or more predicted battery values may be determined based on application of the temporal convolutional neural network to a prospective control profile and observed battery system input values for a designated battery system of the designated type of battery system. An operational instruction may be sent to the designated battery system based on the one or more predicted battery values.

Abstract: Described herein are lithium-metal negative electrodes, lithium-metal liquid-electrolyte electrochemical cells comprising such electrodes, and methods of fabricating such electrodes. In some examples, a lithium-metal negative electrode comprises a base layer comprising aluminum and/or titanium. The lithium-metal negative electrode also comprises a protection layer disposed on and supported by the base layer and comprising copper, silicon, zinc, magnesium, nickel, molybdenum, tungsten, tantalum, and/or silver. Furthermore, the lithium-metal negative electrode comprises a lithium-metal negative active material layer attached to and supported by the protection layer such that the protection layer is positioned between the negative-electrode base layer and the lithium-metal negative active material layer.

Abstract: Described herein are methods and systems for restoring LiMLE cells by cycling such cells using restoring conditions comprising specially selected restoring discharge current (e.g., at least 1 D) and a restoring charge current (e.g., less than 0.5 C). This restoration cycling can be triggered when a LiMLE cell reaches a restoring threshold, determined based on one or more of the following operating and resting conditions: a discharge capacity, an overpotential, an impedance, a direct-current (DC) resistance, the rest period duration, an open circuit voltage, operating discharge and/or charge currents, and an operating cycle count. The restoring threshold is selected to reflect the negative electrode state in a LiMLE cell. The restoring conditions are selected to change this negative electrode state to improve the performance of the LiMLE cell. For example, the restoring discharge can reduce the cell's state of charge (SOC) by at least 10%.

Abstract: Described herein are current collectors comprising metal grids as well as electrodes and lithium-metal cells comprising such current collectors and methods of fabricating such current collectors, electrodes, and lithium-metal cells. A thin current collector comprises a polymer base and a metal layer positioned on, directly interfaces, and supported by one side of the polymer base. A thin current collector also comprises a metal grid, which directly interfaces and is supported by the edge of the polymer base. The metal grid is electrically coupled to the metal layer, e.g., by overlapping or at least forming an interface with the metal layer. In an electrode that further comprises an active material layer supported on the metal layer, the metal grid extends away from the active material layer. In an electrochemical cell, the metal grid can be connected to the metal grids of other electrodes and/or cell tabs.

Abstract: Described herein are electrode-separator integrated assemblies, lithium-metal electrochemical cells comprising such assemblies, and methods of fabricating such assemblies and cells. An assembly can be formed as one continuous structure comprising one type of electrodes (referred to as an assembly electrode) wrapping around multiple other-type electrodes (referred to as non-assembly electrodes). Either positive or negative electrodes can be assembly electrodes, i.e., parts of electrode-separator integrated assemblies. The assembly also comprises a first separator portion and a second separator portion such that the assembly electrode is positioned between the two separator portions. The separator portions can be adhered to the assembly electrode. The separator portions can be independent separate sheets or parts of a single monolithic sheet wrapping around the inner edges of the assembly electrode.

Abstract: Described herein are lithium-metal rechargeable electrochemical cells comprising positive single-crystal nickel-manganese-cobalt (NMC)-containing structures and liquid electrolytes comprising one or more imide-containing salts, such as bis(trifluoromethanesulfonyl)imide (TFSI?)-containing salts, bis(fluorosulfonyl)imide (FSI?)-containing salts, and bis(pentafluoroethanesulfonyl)imide (BETI?)-containing salts. These salts can also include various cations, such as lithium (Li+), potassium (K+), sodium (Na+), cesium (Cs+), n-propyl-n-methylpyrrolidinium (Pyr13+), n-octyl-n-methylpyrrolidinium (Pyr18+), and 1-methyl-1-pentylpyrrolidinium (Pyr15+). For example, imide-containing salts can act as a source of lithium ions in lithium-metal salts. In some examples, the liquid electrolyte further comprises one or more of 1,2-dimethoxyethane (DME), 2,2,2-Trifluoroethyl Ether (TFEE), 1,1,2,2-Tetrafluoroethyl 2,2,3,3-tetrafluoropropyl ether (TFPE), one or more phosphites, and one or more phosphates.

Abstract: Described herein are electrode-separator integrated assemblies, lithium-metal electrochemical cells comprising such assemblies, and methods of fabricating such assemblies and cells. An assembly can be formed as one continuous structure comprising one type of electrodes (referred to as an assembly electrode) wrapping around multiple other-type electrodes (referred to as non-assembly electrodes). Either positive or negative electrodes can be assembly electrodes, i.e., parts of electrode-separator integrated assemblies. The assembly also comprises a first separator portion and a second separator portion such that the assembly electrode is positioned between the two separator portions. The separator portions can be adhered to the assembly electrode. The separator portions can be independent separate sheets or parts of a single monolithic sheet wrapping around the inner edges of the assembly electrode.

Abstract: Described herein are current collectors comprising metal grids as well as electrodes and lithium-metal cells comprising such current collectors and methods of fabricating such current collectors, electrodes, and lithium-metal cells. A thin current collector comprises a polymer base and a metal layer positioned on, directly interfaces, and supported by one side of the polymer base. A thin current collector also comprises a metal grid, which directly interfaces and is supported by the edge of the polymer base. The metal grid is electrically coupled to the metal layer, e.g., by overlapping or at least forming an interface with the metal layer. In an electrode that further comprises an active material layer supported on the metal layer, the metal grid extends away from the active material layer. In an electrochemical cell, the metal grid can be connected to the metal grids of other electrodes and/or cell tabs.

Abstract: Described herein are lithium-metal unit cells and methods of fabricating such cells. A lithium-metal unit cell comprises a negative electrode, a positive electrode, and a separator sheet. The negative electrode comprises a negative polymer base and a negative active material layer adhered to and supported on the negative polymer base and comprising lithium metal. The positive electrode comprises a positive polymer base, a positive current collector adhered to and supported on the positive polymer base, and a positive active material layer adhered to and supported on the positive polymer base such that the positive current collector is positioned between the positive polymer base and the positive active material layer. The separator sheet is positioned between the negative active material layer and the positive active material layer and bonded to the negative base side edges and the positive base side edges.

Abstract: A system including a battery module configured for use in an electric aircraft includes at least a battery cell and a battery module casing. The at least a battery cell includes at least a pair of cell tabs and at least a conductor. The battery module casing includes at least a lithiophobic surface with an ejecta barrier and at least a nonlithiphobic surface that is configured to vent the cell ejecta. The battery module casing closely matches the dimensions of the battery cell.

Abstract: A system for electrical energy production from chemical reagents in a compartmentalized cell includes: at least two electrodes, comprising at least one anode and at least one cathode; at least one separator, that separates the anodes and the cathodes; and an ionic liquid electrolyte system. The system can be a battery or one or more cells of a battery system. The ionic liquid electrolyte system comprises an ionic liquid solvent; an ether co-solvent, comprising a minority fraction, by weight, of the electrolyte; and a lithium salt. In preferred variations, the anode is a lithium metal anode and the cathode is a metal oxide cathode and the separator is a polyolefin separator.

Abstract: Described herein are methods and systems for controlling the charge and discharge characteristics of lithium-metal liquid-electrolyte (LiMLE) electrochemical cells that ensure extended cycle life even at high charge rates. In some examples, a method comprises charging a LiMLE electrochemical cell using a set of charge characteristics and discharging the cell using a set of discharge characteristics. These characteristics are specifically tailored to the cell design. For example, the cell temperature can be higher during the charge than during the discharge, especially for viscous electrolytes. For example, the cell can be heated before charging, e.g., using a separate heater and/or charge-discharge pulses (before or while charging the cell). In the same or other examples, the set of charge characteristics comprises charge pulses such that each pair of charge pulses is separated by a discharge pulse. The current during each discharge pulse can be greater during each charge pulse.

Abstract: Described herein are electrochemical cells fabricated with current collectors comprising polymer bases and metal layers and methods of interconnecting these current collectors or, more specifically, interconnecting their metal layers. For example, a current collector, positioned between two other current collectors, can have an opening allowing these two other current collectors to form a direct interface. This interface not only directly interconnects the metal layers on these two current collectors but also indirectly interconnects the two metal layers of the middle current collector, which are positioned on the opposite sides of the polymer base of this current collector. In some examples, the metal layers of current collectors are reinforced by external metal foils that help to maintain continuity and/or repair any discontinuities in the metal layers when these metal layers are welded together. For example, welding may push portions of the polymer bases away from the weld zone.

Abstract: Described herein are methods and systems for forming electrode stacks. For example, a method may comprise applying in-plane tension to a separator sheet and inspecting the separator sheet while applying the in-plane tension. This under-tension allows identifying any defects on the separator sheets that are not curable by tension, e.g., permanent wrinkles, tears, contaminants, and the like. Furthermore, this in-plane tension can be used for stacking and maintained while an electrode is placed over the separator. The tension can be formed by positioning vacuum clamps along the opposite edges (e.g., long edges) of the separator sheet. For example, one vacuum clamp can extend along the entire separator edge. Alternatively, multiple clamps can be distributed along the edge. Furthermore, additional clamps can be positioned along the remaining two edges (of the rectangular separator sheet). The vacuum clamps can move in various directions and/or rotate to apply the in-plane tension.

Abstract: A system for electrical energy production from chemical reagents in a compartmentalized cell includes: at least two electrodes, comprising at least one anode and at least one cathode; at least one separator, that separates the anodes and the cathodes; and an ionic liquid electrolyte system. The system can be a battery or one or more cells of a battery system. The ionic liquid electrolyte system comprises an ionic liquid solvent; an ether co-solvent, comprising a minority fraction, by weight, of the electrolyte; and a lithium salt. In preferred variations, the anode is a lithium metal anode and the cathode is a metal oxide cathode and the separator is a polyolefin separator.

Abstract: Described herein are battery assemblies that comprise lithium-metal electrochemical cells and pressure-applying structures disposed adjacent to the cells and applying uniform pressure to the cells. Specifically, this uniform pressure is applied between a minimum threshold and a maximum threshold at any operating state of charge of these cells and, in some examples, over the entire operating lifetime of the cells. A pressure-applying structure can be positioned between a pair of adjacent cells or between a cell and an assembly enclosure. In some examples, the footprint of the pressure-inducing structure fully covers the footprint of the negative-electrode planar portion. The pressure-inducing structure may have a stress relaxation of less than 5% and/or a compression set of less than 10%. The pressure-inducing structure may remain in an elastic deformation region at any operating condition. In some examples, the pressure-inducing structure is foam or aerogel.

Abstract: Described herein are battery assemblies that comprise lithium-metal electrochemical cells and lithium-ejecta containment components. A lithium-ejecta containment component is configured to prevent or at least reduce the migration of lithium metal that has been ejected from any of the lithium-metal electrochemical cells. For example, a lithium-ejecta containment component can be positioned between a pair of lithium-metal electrochemical cells and/or between the battery-assembly enclosure and each cell. In the same or other examples, a lithium-ejecta containment component can be integrated into the battery-assembly enclosure and/or cell enclosures. Furthermore, a lithium-ejecta containment component can be configured to absorb and contain the ejected lithium metal. In further examples, a lithium-ejecta containment component is configured to direct the ejected lithium metal away from the battery assembly.

Abstract: A system for electrical energy production from chemical reagents in a compartmentalized cell includes: at least two electrodes, comprising at least one anode and at least one cathode; at least one separator, that separates the anodes and the cathodes; and an ionic liquid electrolyte system. The system can be a battery or one or more cells of a battery system. The ionic liquid electrolyte system comprises an ionic liquid solvent; an ether co-solvent, comprising a minority fraction, by weight, of the electrolyte; and a lithium salt. In preferred variations, the anode is a lithium metal anode and the cathode is a metal oxide cathode and the separator is a polyolefin separator.