How machine learning can extend electroanalytical measurements beyond analytical interpretation.

Electroanalytical measurements are routinely used to estimate material properties exhibiting current and voltage signatures. Analysis of such measurements relies on analytical expressions of material properties to describe the experiments. The need for analytical expressions limits the experiments that can be used to measure properties as well as the properties that can be estimated from a given experiment.

Unconventional Charge Transport in MgCrO and Implications for Battery Intercalation Hosts.

Ion transport in solid-state cathode materials prescribes a fundamental limit to the rates batteries can operate; therefore, an accurate understanding of ion transport is a critical missing piece to enable new battery technologies, such as magnesium batteries. Based on our conventional understanding of lithium-ion materials, MgCrO is a promising magnesium-ion cathode material given its high capacity, high voltage against an Mg anode, and acceptable computed diffusion barriers. Electrochemical examinations of MgCrO, however, reveal significant energetic limitations.

Control of crystal size tailors the electrochemical performance of α-VO as a Mg intercalation host.

α-VO has been extensively explored as a Mg intercalation host with potential as a battery cathode, offering high theoretical capacities and potentials vs. Mg/Mg. However, large voltage hysteresis is observed with Mg insertion and extraction, introducing significant and unacceptable round-trip energy losses with cycling.

Enhanced charge storage of nanometric ζ-VO in Mg electrolytes.

V2O5 is of interest as a Mg intercalation electrode material for Mg batteries, both in its thermodynamically stable layered polymorph (α-V2O5) and in its metastable tunnel structure (ζ-V2O5). However, such oxide cathodes typically display poor Mg insertion/removal kinetics, with large voltage hysteresis. Herein, we report the synthesis and evaluation of nanosized (ca.

Probing Mg Intercalation in the Tetragonal Tungsten Bronze Framework VNbO.

While commercial Li-ion batteries offer the highest energy densities of current rechargeable battery technologies, their energy storage limit has almost been achieved. Therefore, there is considerable interest in Mg batteries, which could offer increased energy densities in comparison to Li-ion batteries if a high-voltage electrode material, such as a transition-metal oxide, can be developed. However, there are currently very few oxide materials which have demonstrated reversible and efficient Mg insertion and extraction at high voltages; this is thought to be due to poor Mg diffusion kinetics within the oxide structural framework.

Tailoring the electrochemical activity of magnesium chromium oxide towards Mg batteries through control of size and crystal structure.

Chromium oxides with the spinel structure have been predicted to be promising high voltage cathode materials in magnesium batteries. Perennial challenges involving the mobility of Mg2+ and reaction kinetics can be circumvented by nano-sizing the materials in order to reduce diffusion distances, and by using elevated temperatures to overcome activation energy barriers. Herein, ordered 7 nm crystals of spinel-type MgCr2O4 were synthesized by a conventional batch hydrothermal method.

Mechanistic insights of Li diffusion within doped LiFePO from Muon Spectroscopy.

The Li ion diffusion characteristics of V- and Nb-doped LiFePO were examined with respect to undoped LiFePO using muon spectroscopy (µSR) as a local probe. As little difference in diffusion coefficient between the pure and doped samples was observed, offering D values in the range 1.8-2.

Enhancing Distorted Metal-Organic Framework-Derived ZnO as Anode Material for Lithium Storage by the Addition of AgS Quantum Dots.

The lithium storage properties of the distorted metal-organic framework-derived nanosized ZnO@C are significantly improved by the introduction of AgS quantum dots (QDs) during the processing of the material. In the thermal treatment, the AgS QDs react to produce Ag nanoparticles and ZnS. The metal nanoparticles act to shorten electron pathways and improve the connectivity of the matrix, and the partial sulfidation of the ZnO surface improves the cycling stability of the material.

Mapping Structure-Composition-Property Relationships in V- and Fe-Doped LiMnPO Cathodes for Lithium-Ion Batteries.

A series of LiMnFeVPO (LMFVP) nanomaterials have been synthesized using a pilot-scale continuous hydrothermal synthesis process (CHFS) and evaluated as high voltage cathodes in Li-ion batteries at a production rate of 0.25 kg h. The rapid synthesis and screening approach has allowed the specific capacity of the high Mn content olivines to be optimized, particularly at high discharge rates.