Abstract: Electrochemical reactivity is driven by the composition and structure of electrode surfaces. Monitoring surface chemistry in operando is thus crucial to understanding the behavior of electrodes yet is often inaccessible either due to resource limitations or to technical challenges in replicating realistic reaction environments. The invention presents a color impedance spectroscopy (CIS)-based technique to access operando surface measurements for mixed ionic-electronic conductors (MIECs). The CIS technique tunes the depth of charge carriers' movement within an electrode material by modulating the frequency of an applied AC electrochemical signal and monitors these changes spectroscopically. The results enable surface sensitivity in conventional bulk spectroscopies and provide new opportunities to characterize the operational behavior of MIEC electrodes.

Abstract: Process for making a composite oxide according to the formula x·Li2Ni1-y1-y2Mny1M1y2O3·(1?x)·LiNi1-zM2zO2 wherein x is in the range of from 0.01 to 0.5, z is in the range of from zero to 0.5, M1 is selected from Ti, Zr, Sn, Ge, Ta, Nb, Sb, W, and Mo, and combinations of at least two of the foregoing, M2 is at least one of Co, Al, Mg, Fe, or Mn, or a combination of at least two of the foregoing, 0.1?y1?0.75, zero?y2?0.05, said process comprising the following steps: (a) providing a particulate hydroxide, oxide or oxyhydroxide of TM where TM has the general formula x·Ni1-y1-y2Mny1M1y·(1?x)Ni1-zM2z, or the respective species without M1 and/or M2, (b) adding a source of lithium, (c) treating the mixture obtained from step (b) thermally under an atmosphere comprising oxygen in two steps: (c) heating the mixture obtained from step (b) to 680 to 800° C. in an atmosphere containing in the range of from 10 to 100 vol-% oxygen, and, (e) heating the intermediate from step (c) to 450 to 580° C.

Abstract: System, methods, and other embodiments described herein relate to improving the estimation of battery life. In one embodiment, a method includes measuring electrochemical data of a battery cell associated with an electrochemical reaction triggered by a test during a diagnostic cycle. The method also includes determining a feature associated with the degradation of the battery cell from the electrochemical data. The method also includes predicting an end-of-life (EOL) of the battery cell by using the feature in a machine learning (ML) model.

Abstract: Process for making a mixed oxide according to the formula Li1+xTM1?xO2 wherein x is in the range of from 0.1 to 0.2 and TM is a combination of elements according to general formula (I) (NiaCobMnc)1-dM1d (I) wherein a is in the range of from 0.30 to 0.38, b being in the range of from zero to 0.05, c being in the range of from 0.60 to 0.70, and d being in the range of from zero to 0.05, M1 is selected from Al, Ti, Zr, W, Mo, Nb, Ta, Mg and combinations of at least two of the forego-ing, a+b+c=1, said process comprising the following steps: (a) providing a particulate hydroxide, oxide or oxyhydroxide of manganese, nickel, and, optionally, at least one of Co and M1, (b) adding a source of lithium, (c) calcining the mixture obtained from step (b) thermally under an atmosphere comprising 0.05 to 5 vol.-% of oxygen at a maximum temperature the range of from 650 to 1000° C.

Abstract: System, methods, and other embodiments described herein relate to improving the cycling of batteries by using data and a hierarchical Bayesian model (HBM) for predicting the cycle life of a cycling protocol. In one embodiment, a method includes classifying cycle life of a battery into a class using battery data from cycling with a protocol, wherein the class represents cycle life distributions of cycling protocols. The method also includes quantifying, using the class in a HBM, variability for the battery induced by the protocol. The method also includes predicting, using the HBM, an adjusted cycle life for the protocol according to the variability. The method also includes communicating the adjusted cycle life to operate the battery.

Abstract: System, methods, and other embodiments described herein relate to improving the cycling of batteries by using data and a hierarchical Bayesian model (HBM) for predicting the cycle life of a cycling protocol. In one embodiment, a method includes classifying cycle life of a battery into a class using battery data from cycling with a protocol, wherein the class represents cycle life distributions of cycling protocols. The method also includes quantifying, using the class in a HBM, variability for the battery induced by the protocol. The method also includes predicting, using the HBM, an adjusted cycle life for the protocol according to the variability. The method also includes communicating the adjusted cycle life to operate the battery.

Abstract: An electrochemical device includes: (1) a compartment; (2) a container including a liquid reactant; and (3) a conveyance mechanism fluidly connected to the container and the compartment and configured to convey the liquid reactant from the container into the compartment, wherein the liquid reactant is a eutectic mixture of two or more different redox-active substances.

Abstract: System, methods, and other embodiments described herein relate to improving the estimation of battery life. In one embodiment, a method includes measuring electrochemical data of a battery cell associated with an electrochemical reaction triggered by a test during a diagnostic cycle. The method also includes determining a feature associated with the degradation of the battery cell from the electrochemical data. The method also includes predicting an end-of-life (EOL) of the battery cell by using the feature in a machine learning (ML) model.

Abstract: A method of using data-driven predictive modeling to predict and classify battery cells by lifetime is provided that includes collecting a training dataset by cycling battery cells between a voltage V1 and a voltage V2, continuously measuring battery cell voltage, current, can temperature, and internal resistance during cycling, generating a discharge voltage curve for each cell that is dependent on a discharge capacity for a given cycle, calculating, using data from the discharge voltage curve, a cycle-to-cycle evolution of cell charge to output a cell voltage versus charge curve Q(V), generating transformations of ?Q(V), generating transformations of data streams that include capacity, temperature and internal resistance, applying a machine learning model to determine a combination of a subset of the transformations to predict cell operation characteristics, and applying the machine learning model to output the predicted battery operation characteristics.

Abstract: A two-step thermochemical gas reduction process based on poly-cation oxides includes repeatedly cycling a thermal reduction step and a gas reduction step. In the thermal reduction the poly-cation oxide is heated to produce a reduced poly-cation oxide and oxygen. In the gas reduction step, the reduced poly-cation oxide is reacted with a gas to reduce the gas, while reoxidizing the poly-cation oxide. The poly-cation oxide has at least two distinct crystal structures at two distinct temperatures and is capable of undergoing a reversible phase transformation between the two distinct crystal structures. For example, the poly-cation oxide may be an entropy tuned mixed metal oxide, such as an entropy stabilized mixed metal oxide, where the entropy-tuning is achieved via change in crystal structure of one of more of the compounds involved. The gas reduction process may be used for water splitting, CO2 splitting, NOx reduction, and other gas reduction processes.

Abstract: A method of probing a multidimensional parameter space of battery cell test protocols is provided that includes defining a parameter space for a plurality of battery cells under test, discretizing the parameter space, collecting a preliminary set of cells being cycled to failure for sampling policies from across the parameter space and include multiple repetitions of the policy, specifying resource hyperparameters, parameter space hyperparameters, and algorithm hyperparameters, selecting a random subset of charging policies, testing the random subset of charging policies until a number of cycles required for early prediction of battery lifetime is achieved, inputting cycle data for early prediction into an early prediction algorithm to obtain early predictions, inputting the early predictions into an optimal experimental design (OED) algorithm to obtain recommendations for running at least one next test, running the recommended tests by repeating from the random subset testing step above, and validating final

Abstract: An electrochemical device includes: (1) a compartment; (2) a container including a liquid reactant; and (3) a conveyance mechanism fluidly connected to the container and the compartment and configured to convey the liquid reactant from the container into the compartment, wherein the liquid reactant is a eutectic mixture of two or more different redox-active substances.

Abstract: A direct thermoelectrochemical heat-to-electricity converter includes two electrochemical cells at hot and cold temperatures, each having a gas-impermeable, electron-blocking membrane capable of transporting an ion I, and a pair of electrodes on opposite sides of the membrane. Two closed-circuit chambers A and B each includes a working fluid, a pump, and a counter-flow heat exchanger. The chambers are connected to opposite sides of the electrochemical cells and carry their respective working fluids between the two cells. The working fluids are each capable of undergoing a reversible redox half-reaction of the general form R?O+I+e?, where R is a reduced form of an active species in a working fluid and O is the oxidized forms of the active species. One of the first pair of electrodes is electrically connected to one the second pair of electrodes via an electrical load to produce electricity.

Abstract: A method of probing a multidimensional parameter space of battery cell test protocols is provided that includes defining a parameter space for a plurality of battery cells under test, discretizing the parameter space, collecting a preliminary set of cells being cycled to failure for sampling policies from across the parameter space and include multiple repetitions of the policy, specifying resource hyperparameters, parameter space hyperparameters, and algorithm hyperparameters, selecting a random subset of charging policies, testing the random subset of charging policies until a number of cycles required for early prediction of battery lifetime is achieved, inputting cycle data for early prediction into an early prediction algorithm to obtain early predictions, inputting the early predictions into an optimal experimental design (OED) algorithm to obtain recommendations for running at least one next test, running the recommended tests by repeating from the random subset testing step above, and validating final

Abstract: A method of using data-driven predictive modeling to predict and classify battery cells by lifetime is provided that includes collecting a training dataset by cycling battery cells between a voltage V1 and a voltage V2, continuously measuring battery cell voltage, current, can temperature, and internal resistance during cycling, generating a discharge voltage curve for each cell that is dependent on a discharge capacity for a given cycle, calculating, using data from the discharge voltage curve, a cycle-to-cycle evolution of cell charge to output a cell voltage versus charge curve Q(V), generating transformations of ?Q(V), generating transformations of data streams that include capacity, temperature and internal resistance, applying a machine learning model to determine a combination of a subset of the transformations to predict cell operation characteristics, and applying the machine learning model to output the predicted battery operation characteristics.

Abstract: A solid-state PEC includes mixed ionic and electronic conducting oxides that allow it to operate at temperatures significantly above ambient utilizing both the light and thermal energy available from concentrated sunlight to dissociate water vapor. The solid-state PEC has a semiconductor light absorber coated with a thin MIEC oxide for improved catalytic activity, electrochemical stability and ionic conduction, which is located between the gas phase and the semiconductor light absorber. As a result, the MIEC oxide provides a facile path for minority carriers to reach the water vapor as well as a path for the ionic carriers to reach the solid electrolyte. Elevated temperature operation allows reasonable band misalignments at the interfaces to be overcome, reduces the required overpotential, and facilitates rapid product diffusion away from the surface.

Abstract: A two-step thermochemical gas reduction process based on poly-cation oxides includes repeatedly cycling a thermal reduction step and a gas reduction step. In the thermal reduction the poly-cation oxide is heated to produce a reduced poly-cation oxide and oxygen. In the gas reduction step, the reduced poly-cation oxide is reacted with a gas to reduce the gas, while reoxidizing the poly-cation oxide. The poly-cation oxide has at least two distinct crystal structures at two distinct temperatures and is capable of undergoing a reversible phase transformation between the two distinct crystal structures. For example, the poly-cation oxide may be an entropy tuned mixed metal oxide, such as an entropy stabilized mixed metal oxide, where the entropy-tuning is achieved via change in crystal structure of one of more of the compounds involved. The gas reduction process may be used for water splitting, CO2 splitting, NOx reduction, and other gas reduction processes.

Abstract: A direct thermoelectrochemical heat-to-electricity converter includes two electrochemical cells at hot and cold temperatures, each having a gas-impermeable, electron-blocking membrane capable of transporting an ion I, and a pair of electrodes on opposite sides of the membrane. Two closed-circuit chambers A and B each includes a working fluid, a pump, and a counter-flow heat exchanger. The chambers are connected to opposite sides of the electrochemical cells and carry their respective working fluids between the two cells. The working fluids are each capable of undergoing a reversible redox half-reaction of the general form R?O+I+e?, where R is a reduced form of an active species in a working fluid and O is the oxidized forms of the active species. One of the first pair of electrodes is electrically connected to one the second pair of electrodes via an electrical load to produce electricity.

Abstract: A solid-state PEC includes mixed ionic and electronic conducting oxides that allow it to operate at temperatures significantly above ambient utilizing both the light and thermal energy available from concentrated sunlight to dissociate water vapor. The solid-state PEC has a semiconductor light absorber coated with a thin MIEC oxide for improved catalytic activity, electrochemical stability and ionic conduction, which is located between the gas phase and the semiconductor light absorber. As a result, the MIEC oxide provides a facile path for minority carriers to reach the water vapor as well as a path for the ionic carriers to reach the solid electrolyte. Elevated temperature operation allows reasonable band misalignments at the interfaces to be overcome, reduces the required overpotential, and facilitates rapid product diffusion away from the surface.

Abstract: A method for converting thermal energy to chemical energy by reducing a reactive oxide substrate at a constant temperature under a first atmosphere with a lower oxygen partial pressure, and then contacting the reduced oxide at the same temperature with a second atmosphere with a higher oxygen partial pressure, during which oxygen is driven into the reduced oxide by the oxygen chemical potential difference between the two atmospheres, thereby leaving fuel behind, i.e. producing fuel. A method for preparing the reactive oxide substrate by using liquid media as a binder and pore former and heating the mixture of the reactive oxide and the liquid media, thereby forming the reactive oxide substrate.