Lithium-ion battery degradation: how to model it.

Predicting lithium-ion battery degradation is worth billions to the global automotive, aviation and energy storage industries, to improve performance and safety and reduce warranty liabilities. However, very few published models of battery degradation explicitly consider the interactions between more than two degradation mechanisms, and none do so within a single electrode. In this paper, the first published attempt to directly couple more than two degradation mechanisms in the negative electrode is reported. The results are used to map different pathways through the complicated path dependent and non-linear degradation space. Four degradation mechanisms are coupled in PyBaMM, an open source modelling environment uniquely developed to allow new physics to be implemented and explored quickly and easily. Crucially it is possible to see 'inside the model and observe the consequences of the different patterns of degradation, such as loss of lithium inventory and loss of active material. For the same cell, five different pathways that can result in end-of-life have already been found, depending on how the cell is used. Such information would enable a product designer to either extend life or predict life based upon the usage pattern. However, parameterization of the degradation models remains as a major challenge, and requires the attention of the international battery community.

Lithium ion battery degradation: what you need to know.

The expansion of lithium-ion batteries from consumer electronics to larger-scale transport and energy storage applications has made understanding the many mechanisms responsible for battery degradation increasingly important. The literature in this complex topic has grown considerably; this perspective aims to distil current knowledge into a succinct form, as a reference and a guide to understanding battery degradation. Unlike other reviews, this work emphasises the coupling between the different mechanisms and the different physical and chemical approaches used to trigger, identify and monitor various mechanisms, as well as the various computational models that attempt to simulate these interactions. Degradation is separated into three levels: the actual mechanisms themselves, the observable consequences at cell level called modes and the operational effects such as capacity or power fade. Five principal and thirteen secondary mechanisms were found that are generally considered to be the cause of degradation during normal operation, which all give rise to five observable modes. A flowchart illustrates the different feedback loops that couple the various forms of degradation, whilst a table is presented to highlight the experimental conditions that are most likely to trigger specific degradation mechanisms. Together, they provide a powerful guide to designing experiments or models for investigating battery degradation.

Use of romiplostim in pregnancy for refractory idiopathic thrombocytopenic purpura: Two case reports with maternal and fetal outcomes and literature review.

Idiopathic thrombocytopenic purpura is a relatively rare complication occurring in pregnancy, with the potential for serious maternal and fetal outcomes. Rarely, the poor response to established first-line therapies results in consideration of second-line therapies, which may have poorly understood risks to the fetus. We report two women with severe idiopathic thrombocytopenic purpura during pregnancy unresponsive to corticosteroids and intravenous immunoglobulin who were treated with romiplostim, a thrombopoietin receptor agonist. One woman with chronic idiopathic thrombocytopenic purpura had a partial response to romiplostim and suffered a post-partum haemorrhage related to uterine atony. The second woman developed severe idiopathic thrombocytopenic purpura in pregnancy and initially responded well to romiplostim. However, a lower segment Caesarean section was performed at 37 weeks for pre-eclampsia. The newborn suffered from severe idiopathic thrombocytopenic purpura and a grade 1 cerebral haemorrhage requiring intravenous immunoglobulin and platelet transfusions. Romiplostim might be a useful therapy for severe idiopathic thrombocytopenic purpura in pregnancy but requires further study.

Aboriginal and Torres Strait Islander women's health: acting now for a healthy future.

This paper summarises the recent RANZCOG Indigenous Women's Health Meeting with recommendations on how the College and its membership can act now to improve the health of Aboriginal and Torres Strait Islander women and infants.