Mapping internal temperatures during high-rate battery applications.

Electric vehicles demand high charge and discharge rates creating potentially dangerous temperature rises. Lithium-ion cells are sealed during their manufacture, making internal temperatures challenging to probe1. Tracking current collector expansion using X-ray diffraction (XRD) permits non-destructive internal temperature measurements2; however, cylindrical cells are known to experience complex internal strain3,4. Here, we characterize the state of charge, mechanical strain and temperature within lithium-ion 18650 cells operated at high rates (above 3C) by means of two advanced synchrotron XRD methods: first, as entire cross-sectional temperature maps during open-circuit cooling and second, single-point temperatures during charge-discharge cycling. We observed that a 20-minute discharge on an energy-optimized cell (3.5 Ah) resulted in internal temperatures above 70 °C, whereas a faster 12-minute discharge on a power-optimized cell (1.5 Ah) resulted in substantially lower temperatures (below 50 °C). However, when comparing the two cells under the same electrical current, the peak temperatures were similar, for example, a 6 A discharge resulted in 40 °C peak temperatures for both cell types. We observe that the operando temperature rise is due to heat accumulation, strongly influenced by the charging protocol, for example, constant current and/or constant voltage; mechanisms that worsen with cycling because degradation increases the cell resistance. Design mitigations for temperature-related battery issues should now be explored using this new methodology to provide opportunities for improved thermal management during high-rate electric vehicle applications.

A novel fuel cell design foroperandoenergy-dispersive x-ray absorption measurements.

A polymer electrolyte fuel cell has been designed to allowoperandox-ray absorption spectroscopy (XAS) measurements of catalysts. The cell has been developed to operate under standard fuel cell conditions, with elevated temperatures and humidification of the gas-phase reactants, both of which greatly impact the catalyst utilisation. X-ray windows in the endplates of the cell facilitate collection of XAS spectra during fuel cell operation while maintaining good compression in the area of measurement. Results of polarisation curves and cyclic voltammograms showed that theoperandocell performs well as a fuel cell, while also providing XAS data of suitable quality for robust XANES analysis. The cell has produced comparable XAS results when performing a cyclic voltammogram to an establishedin situcell when measuring the Pt LIII edge. Similar trends of Pt oxidation, and reduction of the formed Pt oxide, have been presented with a time resolution of 5 s for each spectrum, paving the way for time-resolved spectral measurements of fuel cell catalysts in a fully-operating fuel cell.

Data for an Advanced Microstructural and Electrochemical Datasheet on 18650 Li-ion Batteries with Nickel-Rich NMC811 Cathodes and Graphite-Silicon Anodes.

The data presented here were collected from a commercial LG Chem cylindrical INR18650 MJ1 lithium-ion (Li-ion) battery (approximate nominal specifications: 3.5 Ah, 3.6 V, 12.2 Wh). Electrochemical and microstructural information is presented, the latter collected across several length scales using X-ray computed tomography (CT): from cell to particle. One cell-level tomogram, four assembly-level and two electrode/particle-level 3D datasets are available; all data was collected in the pristine state. The electrochemical data consists of the full current and voltage charge-discharge curves for 400 operational cycles. All data has been made freely available via a repository [10.5522/04/c.4994651] in order to aid in the development of improved computational models for commercially-relevant Li-ion battery materials.

Tailoring hollow structure within NiCoP nanowire arrays via nanoscale Kirkendall diffusion to enhance hydrogen evolution reaction.

Hollow structured nanomaterials with void space available inside the shells can effectively enhance electrocatalytic activity due to their high specific surface area, volume buffer and shell permeability properties. In this study, low-cost and hollow structured bimetal phosphide nanowires are synthesized directly on Ni foam via the Kirkendall effect by using NaH2PO2 as a phosphorizing agent at 350 °C. Both the crystal and hollow structures of the obtained phosphide can be efficiently tuned by controlling the amount of phosphorizing agent and the phosphorizing time. The morphology and microstructure of the obtained phosphides are characterised using various techniques, which indicate that the formation mechanism of the hollow structure is consistent with the Kirkendall effect. The optimized bimetal phosphide sample demonstrates a low onset potential (59 mV) at a current density of 10 mA cm-2, low charge transfer resistance (0.83 Ω) and superior durability in the hydrogen evolution reaction (HER) for water electrolysis. The electrochemical results clearly demonstrate that the hollow structure can efficiently improve the HER properties and the obtained phosphide is a promising HER catalysts for water splitting in KOH or seawater electrolytes.

Data on the theoretical X-Ray attenuation and transmissions for lithium-ion battery cathodes.

This article reports the data required for planning attenuation-based X-ray characterisation e.g. X-ray computed tomography (CT), of lithium-ion (Li-ion) battery cathodes. The data reported here is to accompany a co-submitted manuscript (10.1016/j.matdes.2020.108585 [1]) which compares two well-known X-ray attenuation data sources: Henke et al. and Hubbell et al., and applies methodology reported by Reiter et al. to extend this data towards the practical characterisation of prominent cathode materials. This data may be used to extend beyond the analysis reported in the accompanying manuscript, and may aid in the applications for other materials, not limited to Li-ion batteries.

Investigating the evolving microstructure of lithium metal electrodes in 3D using X-ray computed tomography.

The growth of electrodeposited lithium microstructures on metallic lithium electrodes has prevented their use in rechargeable lithium batteries due to early performance degradation and safety implications. Understanding the evolution of lithium microstructures during battery operation is crucial for the development of an effective and safe rechargeable lithium-metal battery. This study employs both synchrotron and laboratory X-ray computed tomography to investigate the morphological evolution of the surface of metallic lithium electrodes during a single cell discharge and over numerous cycles, respectively. The formation of surface pits and the growth of mossy lithium deposits through the separator layer are characterised in three-dimensions. This has provided insight into the microstructural evolution of lithium-metal electrodes during rechargeable battery operation, and further understanding of the importance of separator architecture in mitigating lithium dendrite growth.

Laser-preparation of geometrically optimised samples for X-ray nano-CT.

A robust and versatile sample preparation technique for the fabrication of cylindrical pillars for imaging by X-ray nano-computed tomography (nano-CT) is presented. The procedure employs simple, cost-effective laser micro-machining coupled with focused-ion beam (FIB) milling, when required, to yield mechanically robust samples at the micrometre length-scale to match the field-of-view (FOV) for nano-CT imaging. A variety of energy and geological materials are exhibited as case studies, demonstrating the procedure can be applied to a variety of materials to provide geometrically optimised samples whose size and shape are tailored to the attenuation coefficients of the constituent phases. The procedure can be implemented for the bespoke preparation of pillars for both lab- and synchrotron-based X-ray nano-CT investigations of a wide range of samples.

Development of a PtSn bimetallic catalyst for direct fuel cells using bio-butanol fuel.

Pt and PtSn catalysts were studied for n-butanol electro-oxidation at various temperatures. PtSn showed a higher activity towards butanol electro-oxidation compared to Pt in acidic media. The onset potential for n-butanol oxidation on PtSn is ∼520 mV lower than that found on Pt, and significantly lower activation energy was found for PtSn compared with that for Pt.

Raman spectroscopy as a probe of temperature and oxidation state for gadolinium-doped ceria used in solid oxide fuel cells.

Raman spectroscopy is a noninvasive and highly sensitive analytical technique capable of identifying chemical compounds in environments that can mimic SOFC operating conditions. Here we demonstrate the use of Raman spectroscopy to perform local thermal and temporal measurements, both of which are essential if phase formation diagrams are to be mapped out and compared to thermodynamic phase stability predictions. We find that the time resolution of the Raman technique is more than sufficient to capture essential dynamic effects associated with a change of chemical composition.

Engineering porous materials for fuel cell applications.

Porous materials play an important role in fuel cell engineering. For example, they are used to support delicate electrolyte membranes, where mechanical integrity and effective diffusivity to fuel gases is critical; they are used as gas diffusion layers, where electronic conductivity and permeability to both gas and water is critical; and they are used to construct fuel cell electrodes, where an optimum combination of ionic conductivity, electronic conductivity, porosity and catalyst distribution is critical. The paper will discuss these characteristics, and introduce the materials and processing methods used to engineer porous materials within two of the leading fuel cell variants, the solid oxide fuel cell and the polymer electrolyte membrane fuel cell.

Mutations of the microsomal triglyceride-transfer-protein gene in abetalipoproteinemia.

Elevated plasma levels of apolipoprotein B (apoB)-containing lipoproteins constitute a major risk factor for the development of coronary heart disease. In the rare recessively inherited disorder abetalipoproteinemia (ABL) the production of apoB-containing lipoproteins is abolished, despite no abnormality of the apoB gene. In the current study we have characterized the gene encoding a microsomal triglyceride-transfer protein (MTP), localized to chromosome 4q22-24, and have identified a mutation of the MTP gene in both alleles of all individuals in a cohort of eight patients with classical ABL. Each mutant allele is predicted to encode a truncated form of MTP with a variable number of aberrant amino acids at its C-terminal end. Expression of genetically engineered forms of MTP in Cos-1 cells indicates that the C-terminal portion of MTP is necessary for triglyceride-transfer activity. Deletion of 20 amino acids from the carboxyl terminus of the 894-amino-acid protein and a missense mutation of cysteine 878 to serine both abolished activity. These results establish that defects of the MTP gene are the predominant, if not sole, cause of hereditary ABL and that an intact carboxyl terminus is necessary for activity.

Microsomal triglyceride transfer protein activity remains unchanged in rat livers under conditions of altered very-low-density lipoprotein secretion.

Microsomal triglyceride transfer protein (MTP) is a heterodimeric protein consisting of a unique 97 kDa subunit and protein disulphide isomerase, that mediates the transfer of lipid between membranes and nascent lipoproteins. Mutations in the gene encoding the 97 kDa subunit of the protein cause the rare autosomal recessive disorder abetalipoproteinaemia. Recent findings in cultured cells indicate that the 5' promoter region contains an insulin-responsive element, suggesting that the gene is responsive to insulin regulation. In this study we examined two cases where very-low-density lipoprotein (VLDL) secretion is markedly reduced: the streptozotocin-diabetic rat and 10-day-old suckling rats. In both cases MTP activity was unaltered compared with that in control animals. Equal levels of MTP were also apparent in the livers of all groups of animals, as measured by immunoblotting with an anti-MTP antiserum. These findings indicate that factors other than MTP activity are responsible for the reduction in hepatic VLDL triglyceride secretion observed in the suckling and diabetic animals.

Microsomal triglyceride transfer protein, the abetalipoproteinemia gene product, mediates the secretion of apolipoprotein B-containing lipoproteins from heterologous cells.

Apolipoprotein (apo) B is an obligatory component of triglyceride-rich lipoproteins. In the rare autosomal recessive disorder abetalipoproteinemia (ABL), no triglyceride-rich lipoproteins are secreted. Mutations in the gene encoding the 97-kDa subunit of a microsomal triglyceride transfer protein (MTP) cause ABL (Sharp, D., Blinderman, L., Combs, K. A., Klenzle, B., Ricci, B., Wager-Smith, K., Gil, C. M., Turck, C. W., Bouma, M. E., Rader, D. J., Aggerbeck, L. P., Gregg, R. E., Gordon, D. A., and Wetterau, J. R. (1993) Nature 365, 65-69; Shoulders, C. C., Brett, D. J., Bayliss, J. D., Narcisi, T. M., Jarmuz, A., Grantham, T. T., Leoni, P. R. D., Bhattacharya, S., Pease, R. J., Cullen, P. M., Levi, S., Byfield, P. G. H., Purkiss, P., and Scott, J. (1993) Hum. Mol. Genet. 2, 2109-2116). Here we have examined whether MTP is both necessary and sufficient to mediate the secretion of apoB-containing lipoproteins from cells that do not normally express either of these proteins. Carboxyl-terminal truncated forms of apoB, apoB17, and apoB41 on the centile system were expressed in COS-1 cells. ApoB17 was secreted whereas apoB41 was unable to traverse the secretory pathway. Cotransfection of apoB41 and MTP promoted the secretion of apoB41 as a buoyant lipoprotein particle with a modal density of 1.15 g/ml. When cotransfected COS-1 cells were cultured under conditions that increase the secretion of apoB100 from HepG2 cells, secretion of apoB41 was similarly increased. N-Acetyl-leucyl-leucyl-norleucinal (ALLN), a calpain I inhibitor, abolished intracellular degradation of apoB41 and increased secretion 2.5-fold. Oleate, a substrate for triglyceride synthesis, reduced degradation from 50 to 19% and increased secretion by 2.5-fold. The effects of ALLN and oleate were additive. We conclude that the secretion of apoB from COS-1 cells cotransfected with apoB and MTP is determined by the competitive processes of lipoprotein assembly and intracellular degradation in the endoplasmic reticulum and that MTP is the only tissue-specific component, other than apoB, required for the secretion of apoB-containing lipoproteins.

Abetalipoproteinemia is caused by defects of the gene encoding the 97 kDa subunit of a microsomal triglyceride transfer protein.

Abetalipoproteinemia is an inherited disorder of lipoprotein metabolism. Affected individuals produce virtually no circulating apolipoprotein B-containing lipoproteins (chylomicrons, very low density lipoprotein, low density lipoprotein and lipoprotein (a)). Malabsorption of the antioxidant vitamin E occurs, leading to spinocerebellar and retinal degeneration. Biochemical and genetic studies show that abetalipoproteinemia is not a defect of lipid biosynthesis or of the apolipoprotein B gene. Instead a microsomal triglyceride transfer protein, which exists as a complex with protein disulphide isomerase in the endoplasmic reticulum, has been implicated. We have cloned and sequenced the human cDNA encoding microsomal triglyceride transfer protein. The predicted amino acid sequence shows extensive homology to vitellogenin, the precursor of the lipovitellin complex, which has been shown by X-ray crystallography to contain a large lipid storage cavity. Microsomal triglyceride transfer protein is expressed in ovary, testis and kidney, in addition to liver and small intestine. A homozygous mutation that disrupts splicing has been identified in affected siblings with classical abetalipoproteinemia. These results elucidate a key process in the packaging of apolipoprotein B with lipid, and should increase our understanding of the processes regulating the production of atherogenic lipoproteins.

Characterization of genetic markers in the 5'flanking region of the apo A1 gene.

Genetic variation of apo A1/C3/A4 is associated with hyperlipidaemia and coronary heart disease. We report the polymerase chain reaction (PCR) conditions for determining three polymorphic sites in the 5'flanking region of apoA1 using DNA prepared from small aliquots of whole blood. These polymorphisms identify six haplotypes that will be of value in genetic studies.