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Li-ion batteries will lose both capacity and power over time due to calendar aging caused by slow parasitic processes that consume Li+ ions. Studying and mitigating these processes is traditionally an equally slow venture, which is especially taxing for the validation of new active materials and electrolyte additives. Here, we evaluate whether potentiostatic holds can be used to accelerate the diagnosis of Li+ loss during calendar aging. The technique is based on the idea that, under the right conditions, the current measured as the cell voltage is held constant can be correlated with the instantaneous rate of side reactions. Thus, in principle, these measurements could capture the rate of capacity fade in real time. In practice, we show that this method is incapable of quantitatively forecasting calendar aging trends. Instead, our study demonstrates that potentiostatic holds can be applied for initial qualitative screening of systems that exhibit promising long-term stability, which can be useful to shrink the parameter space for calendar aging studies. By facilitating the identification of improved formulations, this approach can help accelerate innovation in the battery industry.

The growing demand for lithium‐ion batteries to power electric vehicles and other energy‐dense devices continues to fuel the need for cathodes of increasingly higher nickel in cathodes. The relentless pursuit of high Ni content, however, raises concerns on compromising cell lifetime and safety, especially under high‐voltage operation. Alternative to the traditional design of uniform or core–shell composition, we report a rational control of local stoichiometry in high‐Ni cathodes, enabling their high thermal and cycling stabilities—up to 258 °C at the fully charged state and 91.4% capacity retention for 100 cycles between 2.7 and 4.4 V. Multimodal synchrotron X‐ray characterization unveils the heterostructure of secondary particles, featuring a high‐Ni core (LiNi0.90Mn0.05Co0.05O2) covered by a thin Ni‐gradient layer that remains stable over prolonged cycling due to suppressed oxygen release and structural deterioration. This work underlines, the intricate interplay between local stoichiometry and redox reactions in stabilizing high‐Ni cathodes for high‐voltage operation while ensuring safety. [ABSTRACT FROM AUTHOR]

Enabling fast charging of Li-ion batteries will be a key step towards realizing the technology's full potential in electric vehicles. Currently, fast charging is limited by a variety of processes that reduce cell capacity upon extended cycling. Using a multimodal approach combining incremental capacity analysis (dQ/dV), high energy X-ray diffraction (HEXRD), and mass spectrometry titration (MST), we identify specific degradation mechanisms—including Li plating, dead LixC6 formation, Li2C2 formation, solid carbonate solid-electrolyte interphase (SEI) deposition, and loss of positive electrode active material (LAMPE)—that occur during extended fast charge cycling. We find that Li plating is the major source of capacity loss in cells cycled at 6C, while non-carbonate SEI species deposition on the graphite anode is the main source of capacity loss when cycled at 4C. We also study local degradative phenomena by examining specific ∼1–5 cm2 regions of the cells using HEXRD and MST. We find that plated Li is often collocated with dead LixC6, Li2C2, and solid carbonate SEI species, and these additional species cumulatively account for ∼20% of the capacity lost during 6C cycling. Finally, in a cell with an anomalously high amount of LAMPE (quantified via dQ/dV), we find that regions of cathode degradation were accompanied by non-carbonate SEI products on the adjacent region of the anode. We postulate that this phenomenon arises due to crosstalk between the electrodes, wherein soluble electrolyte oxidation products formed at the delithiated cathode migrate to the graphite anode and are ultimately deposited on the graphite surface. This work demonstrates the utility of combining multiple characterization techniques to reveal a more holistic understanding of degradative phenomena that occur across multiple length scales during fast charge. [ABSTRACT FROM AUTHOR]

Battery performance is strongly correlated with electrode microstructure and weight loading of the electrode components. Among them are the carbon-black and binder additives that enhance effective conductivity and provide mechanical integrity. However, these both reduce effective ionic transport in the electrolyte phase and reduce energy density. Therefore, an optimal additive loading is required to maximize performance, especially for fast charging where ionic transport is essential. Such optimization analysis is however challenging due to the nanoscale imaging limitations that prevent characterizing this additive phase and thus quantifying its impact on performance. Herein, an additive-phase generation algorithm has been developed to remedy this limitation and identify percolation threshold used to define a minimal additive loading. Improved ionic transport coefficients from reducing additive loading has been then quantified through homogenization calculation, macroscale model fitting, and experimental symmetric cell measurement, with good agreement between the methods. Rate capability test demonstrates capacity improvement at fast charge at the beginning of life, from 37% to 55%, respectively for high and low additive loading during 6C CC charging, in agreement with macroscale model, and attributed to a combination of lower cathode impedance, reduced electrode tortuosity and cathode thickness. [ABSTRACT FROM AUTHOR]

As the battery industry shifts toward high Ni content cathodes, such as LiNi0.8Mn0.1Co0.1O2 [NMC811], a complete understanding of the degradation mechanisms of NMC811 under extreme fast charging (XFC) (XFC, ≤10–15 min charging) conditions is needed. Such comprehensive understanding would identify the most critical materials gaps that need to be addressed for enabling XFC long‐life cells for electric vehicles. This study maps out the key aging mechanisms for NMC811 cycled at different XFC conditions (between 1C and 9C) for up to 1000 cycles. To acquire a fundamental understanding of utilization and degradation, cells are evaluated using a range of electrochemical techniques, and multimodal and multiscale microscopy techniques to quantify chemical, structural, and crystallographic degradation as a function of cycling conditions for the NMC cathode. When comparing NMC811 to NMC532, it is observed that NMC811 has a greater subsurface crystallographic degradation and displays a similar magnitude of subparticle cracking. However, the NMC811 maintains superior performance despite those advanced degradations. The superior cycle life performance is attributed to the NMC811 particles having radially oriented grains and improved transport properties. NMC811 shows between 4.6× and 3.15× reduction in capacity fade than NMC532 for charging rates between 4C (e.g., 15‐min charging) and 6C (10‐min charging). [ABSTRACT FROM AUTHOR]

Batteries capable of extreme fast-charging (XFC) are a necessity for the deployment of electric vehicles. Material properties of electrodes and electrolytes along with cell parameters such as stack pressure and temperature have coupled, synergistic, and sometimes deleterious effects on fast-charging performance. We develop a new experimental testbed that allows precise and conformal application of electrode stack pressure. We focus on cell capacity degradation using single-layer pouch cells with graphite anodes, LiNi0.5Mn0.3Co0.2O2 (NMC532) cathodes, and carbonate-based electrolyte. In the tested range (10–125 psi), cells cycled at higher pressure show higher capacity and less capacity fading. Additionally, Li plating decreases with increasing pressure as observed with scanning electron microscopy (SEM) and optical imaging. While the loss of Li inventory from Li plating is the largest contributor to capacity fade, electrochemical and SEM examination of the NMC cathodes after XFC experiments show increased secondary particle damage at lower pressure. We infer that the better performance at higher pressure is due to more homogeneous reactions of active materials across the electrode and less polarization through the electrode thickness. Our study emphasizes the importance of electrode stack pressure in XFC batteries and highlights its subtle role in cell conditions. [ABSTRACT FROM AUTHOR]

Porous Li-ion electrodes contain active particles, ion transporting electrolyte, and carbon-binder networks. While macrohomogeneous models are often used to predict electrode behavior, accurate predictions remain challenging, owing to the incomplete understanding of the critical role of carbon-binder networks and how they affect the electrochemical response. The present study systematically characterizes these effects in terms of effective properties by utilizing macrohomogeneous models to analyze the measured responses for electrodes with different carbon-binder content, electrode thickness, and porosity but with identical materials. We find that the impact of the carbon-binder network is more severe than previously thought. Even for low carbonbinder content (5 %wt. dry electrode), the presence of the network decreases the reaction area and increases the ion transport resistance, negatively impacting electrode performance. These effects scale with not just porosity or active material volume but also with carbon-binder content. The findings underscore the importance of connecting all effective properties to electrode specifications in a full factorial sense to transform the electrode design paradigm. [ABSTRACT FROM AUTHOR]

Owing to their high specific capacity and suitably low operating potential, silicon-based anodes are an attractive alternative to graphite in next-generation lithium-ion batteries. However, silicon anodes suffer from low initial coulombic efficiency and fast capacity decay, limiting their widespread application. Pre-lithiation strategies are highly appealing to compensate for irreversible active lithium loss and to boost the cell energy density. In this work, we maximize the cell energy density by direct pre-lithiation of the NMC (LiNi0.5Mn0.3Co0.2O2) cathode to Li1+xNMCO2 without introducing inactive deadweight to either electrode. First, we demonstrate that Li1+xNMCO2 can be synthesized chemically, via reaction between NMC and lithium napthalide, and electrochemically. The NMC cathode is tolerant of a one-time over-lithiation up to 60 mA h gNMC−1, giving capacity retention on par with untreated NMC in half cell electrochemical cycling. Using synchrotron X-ray absorption spectroscopy (ex situ) and diffraction (in situ), we demonstrate that higher amounts of over-lithiation lead to local structure distortion – driven by transition metal reduction to Jahn–Teller active Mn3+ and Co2+ – as well as bulk structural hysteresis during over-lithiation and layer "buckling" that increases the amount of lithium extracted from the structure in the charged state. The Li1+xNMCO2 with low-to-moderate over-lithiation capacity (23, 46, and 70 mA h gNMC−1) is proven to be a highly effective dual-purpose lithium source and cathode material in full cell tests with a commercially relevant Si–graphite anode. These cells show higher capacity, superior cycle life, and improved coulombic efficiencies when compared to those with stoichiometric NMC cathodes. This study introduces a new and simple method to pre-lithiate layered transition metal oxide cathodes, opening up new possibilities for the development of high energy density lithium-ion batteries with next-generation anodes. [ABSTRACT FROM AUTHOR]

Twenty‐four single‐layer ≈32 mAh pouch cells are tested to determine the effect of electrode porosity on lithium plating. Twelve cells contain a graphite electrode that is 26% porous, and 47% for the other twelve. The cells are cycled using a 6‐C charge and a C/2 discharge protocol at temperatures in the range of 20‐50 °C. A macro‐homogeneous electrochemical model and microstructure analysis tool set are used to help interpret experimental observations for the effect of anode porosity and ambient temperature on fast‐charging performance. Comparison between the two also highlights gaps in current theoretical understanding that need to be addressed. In post‐test examination, lithium plating is seen in all cells, regardless of porosity. Elevated temperature is shown to reduce the amount of lithium plating and improve initial fast‐charge capacity, but also changes the rate of other, less well‐understood degradation mechanisms. Apparent kinetic rate laws, At + Bt1/2, where A and B are constants, can be fit to most of the capacity loss and resistance increase data. The relative magnitudes of A and B change with temperature and porosity. The capacity loss data at 50 °C from the high‐porosity cells are fit by a logistics rate law. [ABSTRACT FROM AUTHOR]

Purpose: Soft tissue sarcomas (STS) account for 8% of all cancers in adolescents and young adults (AYAs). Metastatic STS contribute significantly to disease-related mortality in this age group; however, data are limited due to under-representation in clinical trials. Methods: AYAs aged 18–39 years, diagnosed with metastatic STS between 1990 and 2012, were identified from The Royal Marsden Hospital database. Outcomes of interest were clinical characteristics, treatment patterns, overall survival (OS), and prognostic factors. Results: Overall, 455 patients were included. Median age at diagnosis of metastatic STS was 33 years (interquartile range [IQR] 27–37 years). The most common histological subtypes were leiomyosarcoma (n = 68, 15%), synovial sarcoma (n = 68, 15%), Ewing sarcoma (n = 44, 10%), and rhabdomyosarcoma (n = 35, 8%). Treatments included systemic therapy (n = 395, 87%; median 2 lines [IQR 1–3]; clinical trial n = 93, 22%), radiotherapy (n = 297, 66%), and metastasectomy (n = 191, 43%). Median duration between last chemotherapy regimen and death was 4.6 months (IQR 2–10). Median OS was 19.2 months (95% confidence interval [CI] 15.8–22.2); 5-year OS was 16%. Of common subtypes, patients with rhabdomyosarcoma had the worst OS (8.8 months; 95% CI 7.9–11.4). Adverse prognostic factors included male gender, synchronous metastases, bone or liver metastases, first-line polychemotherapy, and no metastasectomy. Conclusions: Outcomes were variable; patients with supposed chemosensitive subtypes had particularly poor survival. The diverse behavior of STS in AYAs highlights the need for subtype-specific clinical trials. [ABSTRACT FROM AUTHOR]

Purpose. Desmoid-type fibromatosis (DTF) is a rare, nonmetastasising soft tissue tumour. Symptoms, unpredictable growth, lack of definitive treatments, and the chronic character of the disease can significantly impact health-related quality of life (HRQoL). We aimed at identifying the most important HRQoL issues according to DTF patients in two countries, in order to devise a specific HRQoL questionnaire for this patient group. Methods. DTF patients and healthcare providers (HCPs) from the Netherlands and the United Kingdom individually ranked 124 issues regarding diagnosis, treatment, follow-up, recurrence, living with DTF, healthcare, and supportive care experiences, according to their relevance. Descriptive statistics were used to calculate priority scores. Results. The most highly ranked issues by patients (n = 29) were issues concerning "tumour growth," "feeling that there is something in the body that does not belong there," and "fear of tumour growth into adjacent tissues or organs" with mean (M) scores of 3.0, 2.9, and 2.8, respectively (Likert scale 1–4). British patients scored higher on most issues compared to Dutch patients (M 2.2 vs. M 1.5). HCPs (n = 31) gave higher scores on most issues compared to patients (M 2.3 vs. M 1.8). Conclusion. This study identified the most relevant issues for DTF patients, which should be included in a DTF-specific HRQoL questionnaire. Additionally, we identified differences in priority scores between British and Dutch participating patients. Field testing in a large, international cohort is needed to confirm these findings and to devise a comprehensive and specific HRQoL questionnaire for DTF patients. [ABSTRACT FROM AUTHOR]

Li-ion battery (LIB) research has continuing importance for the entire range of applications from consumer products to vehicle electrification and grid stabilization. In many cases, standard electrochemical methods only provide an overall voltage or specific capacity, giving an inadequate description of parallel redox processes or chemical gradients at the particle and pack level. X-ray absorption fine structure (XAFS) is frequently used to augment bulk electrochemical data, as it provides element-specific changes in oxidation state and local atomic structure. Such microscopic descriptors are crucial for elucidating charge transfer and structural changes associated with bonding or site mixing, two key factors in evaluating state of charge and modes of cell failure. However, the impact of XAFS on LIB research has been significantly constrained by a logistical barrier: contemporary XAFS work is performed almost exclusively at synchrotron X-ray light sources, where beamtime is infrequent and experiment time-frames are limited. Here we show that modern laboratory-based XAFS cannot only be applied to, e.g., characterization of ex situ LIB electrode materials, but can also be used for operando studies at industrially-relevant charging rates in a standard pouch cell preparation. Such capability enables accelerated discovery of new materials and improved operation modes for LIBs. [ABSTRACT FROM AUTHOR]

Enabling a 10 min fast charge for electric vehicles is a possible route to reduce range anxiety and increase the utility of electric vehicles. While lithium plating during fast charging is a known challenge, the full suite of limitations which occur in full cells during a 10 min fast charge are unknown. In the present work the central constraints of extreme fast charging are explored through extensive experiments and analysis in single layer graphite/NMC532 pouch cells. Methods of developing fast-charging protocols considering the impedance and transport limitations are presented and the relative benefits of altering the charging rate, profile, relaxation, etc., are investigated. Analysis during and at the end of cycling identified both known and unexpected aging pathways. The most distinct outcomes from the work are a significant increase in cell-to-cell variability as the number of fast charge cycles increase [up to 11% (1s)] and the identification of distinct aging of the NMC532 positive electrode including cracking of the secondary particles and a trend toward under-lithiation of the positive electrode. While significant aging of the positive electrode was observed, only a few conditions had discernible Li plating and no distinct reversible Li signature was seen during periodic reference performance tests. [ABSTRACT FROM AUTHOR]

To improve electric vehicle market acceptance, the charge time of their batteries should be reduced to 10-15 minutes. However, achieving 4C to 6C charge rates with today's batteries is only possible for cells with thin electrodes coming at the expense of low energy density and high battery manufacturing cost. An electrochemical model is validated versus high rate charge data for cells with several loadings. The model elucidates that the main limitations for high energy density cells are poor electrolyte transport resulting in salt depletion within the anode and Li plating at the graphite/separator interface. Next, the model is used to understand what future electrode and electrolyte properties can help enable 4C and 6C charging. Ideally, future electrolytes would be identified with 2X conductivity, 3-4X diffusivity, and transference number of 0.5-0.6. Alternatively charging at elevated temperatures enhances electrolyte transport by 1.5X conductivity and 2-3X diffusivity with a negligible effect on transference number. Another effective strategy to enable 4C and 6C charging is reducing electrode tortuosity. Conversely, increasing electrode porosity and negative/positive ratio are ineffective strategies to improve fast charge capability. [ABSTRACT FROM AUTHOR]

In this work, artificial aluminum-bearing interphases are formed on LiNi0.5Mn0.3Co0.2O2 (NMC532) cathodes via wet-chemical surface treatments with different solvents, aluminum precursors, loading levels, and annealing conditions. The effects of different surface-treatment conditions on interphase chemistries, morphologies, and local atomic environments are studied with the combination of surface-sensitive electron microscopy and local-probe solid state nuclear magnetic resonance techniques. A variation of Al2O3, LiAlO2, and other lithium-bearing species with different phases and morphologies are formed as an interphase on top of NMC532, controlled by the polarity of solvent systems, the corrosivity of aluminum salts, the initial alumina loading, and the annealing temperature. The nature of these initial surface interphases shows great influence on electrode impedance, initial capacities, and capacity retention rates in electrochemical tests. Post-electrochemistry characterizations on cycled cathodes show that surface LiAlO2 phases are relatively stable against the potential HF etching, whereas Al2O3 is reacted and consumed. Both half-cell and full-cell testing results of cathodes treated by optimized protocols demonstrate remarkable improvements in the capacity retention compared with the baseline. These fundamental understandings on interphase chemistries provide deep insights to the control of cathode surfaces and map-out important guidelines for the design of scalable cathode coatings. [ABSTRACT FROM AUTHOR]

Simple Summary: Desmoid-type fibromatosis (DTF) is an uncommon soft tissue tumour with a high recurrence rate after resection. DTF does not metastasise, but its locally aggressive tumour growth and chronic character can cause significant morbidity. Although overall mortality is low, patients can experience a high symptom burden, making assessment of health-related quality of life (HRQoL) highly relevant. At present, data on HRQoL in DTF patients are limited. The QUALIFIED study aims to (1) pre-test a previously developed DTF-specific HRQoL tool (the DTF-QoL); (2) evaluate prevalence of HRQoL issues in adult DTF patients; and (3) identify subgroups at risk of impaired HRQoL. An international, multicentre, cross-sectional, observational cohort study will be conducted to validate the DTF-specific HRQoL questionnaire and to gain more insight into the issues experienced by DTF patients. This information will help to improve clinical practice, symptom control and patient satisfaction. When validated, the DTF-QoL can be used in both clinical and research settings to evaluate HRQoL of DTF patients. Sporadic desmoid-type fibromatosis (DTF) is a rare soft tissue tumour with an unpredictable clinical course. These tumours are incapable of metastasising, but their local aggressive tumour growth and tendency to recur locally can result in a substantial symptom burden. Measuring the impact of DTF on health-related quality of life (HRQoL) can be challenging due to the variable clinical presentation of the disease. Therefore, a HRQoL instrument assessing DTF-specific issues is needed. The QUALIFIED study aims to (1) pre-test a previously developed DTF-specific HRQoL tool (the DTF-QoL); (2) evaluate prevalence of HRQoL issues in adult DTF patients; and (3) identify subgroups at risk of impaired HRQoL. This study (NCT04289077) is an international, multicentre, cross-sectional, observational cohort study. Patients ≥ 18 years with sporadic DTF from the Netherlands and the United Kingdom will be invited to complete a set of questionnaires specifically composed for this patient group. Questionnaires will be completed using PROFILES (Patient Reported Outcomes Following Initial treatment and Long-term Evaluation of Survivorship). Analyses will include testing the psychometric properties of the DTF-QoL and evaluating the prevalence of HRQoL issues using the DTF-QoL, EORTC QOL-C30 and EQ-5D-5L, among other questionnaires. This study will provide insight into HRQoL issues experienced by patients with DTF. Awareness of these issues and the implementation of the DTF-QoL in research and clinical practice can help to improve overall HRQoL and to provide personalised care. [ABSTRACT FROM AUTHOR]

Background: Tyrosine kinase inhibitors (TKI) have revolutionized the treatment of gastrointestinal stromal tumors (GIST) although most patients develop resistance to first and second-line therapies. Regorafenib, an oral multi-targeted TKI, has demonstrated benefit in previously treated GIST patients., Methods: We assessed safety and activity of regorafenib in patients treated within the Managed Access Program (MAP). All consecutive patients with advanced GIST who had progressed on or were intolerant to imatinib and sunitinib were recruited from the Royal Marsden and University College Hospitals. We retrospectively reviewed the data for response, toxicity, treatment duration and survival. Response was assessed by RECIST and Choi criteria. Toxicity was graded according to CTCAE v4.0 criteria., Results: 20 patients were included in the MAP in the UK between 3/2013 and 9/2013. Median age was 68 (range 45-87), 65% of patients were male. Performance Status was 0-1 for 18 patients (90%), 2 for 2 patients (10%). The median treatment duration was 9.25 months (range 0.1-15.33). 18 patients were assessable for response and all patients attained a best response of at least stable disease. At a median follow-up of 12.6 months, there were 2 partial responses (11%) by RECIST and 7 partial responses (39%) according to Choi criteria. 7 patients remain on regorafenib. 3 patients discontinued treatment due to unacceptable adverse events; fistulation, myalgia and fatigue. 10 (50%) patients had grade 3 toxicities and 11 (55%) patients required a dose reduction. Median PFS was 9.4 months (95% Cl: 6.2-not calculable) and median OS was 12.2 months (95% Cl: 10.5-not calculable). Notably, prolonged stable disease was seen in 1 patient with exon 9 mutation and 1 patient with PDGFR D842V mutation., Conclusions: These data demonstrate encouraging activity and tolerability of regorafenib in routine clinical practice. The documented adverse events are in line with previous trial data.