Dose-Escalated vs. Conventional Hypofractionated Radiotherapy for Lung Cancer Patients in Predominantly Central Locations

PURPOSE/OBJECTIVE(S)

Hypofractionated radiation therapy (HFRT) is an increasingly utilized treatment option for patients with lung cancers unamenable to stereotactic body radiotherapy (SBRT). Conventional HFRT (C-HFRT) is often prescribed to 60 Gy in 15 fractions, which has a lower biologically effective dose (BED10 of 84.0) than SBRT. We compared outcomes of patients treated with a dose-escalated HFRT regimen (DE-HFRT, 72 Gy in 18 fractions, BED10 of 100.8) to those treated with C-HFRT. We aimed to evaluate local control (LC), overall survival (OS), and grade 3+ toxicity between patients who received C-HFRT vs. DE-HFRT as we hypothesized DE-HFRT may be superior/equivalent to C-HFRT.

MATERIALS/METHODS

A database was created of all patients at our institution who received either thoracic C-HFRT or DE-HFRT between 2013 and 2020. Baseline variables were compared by chi-square analysis and logistic regression. We analyzed the association between treatment regimens with LC and OS (log-rank test and Cox proportional hazards regression), as well as grade 3+ toxicity.

RESULTS

A total of 107 patients were included, among whom 55 (51.4%) received C-HFRT and 52 (48.6%) received DE-HFRT. Median age was 73, 88.8% of patients had non-small cell lung cancer, 81.3% received lung-only treatment, and 52.3% had an ultra-central tumor location (within 1 cm of proximal tracheobronchial tree, esophagus, or heart). Patients with DE-HFRT were more likely to have lung-only treatment (92.3% vs. 70.9%, p = 0.005) and stage I disease (47.1% vs 24.1%, p = 0.01) than those with C-HFRT, but had a similar proportion of ultra-central tumors (57.1% vs. 54.9%, p = 0.82). Patients with DE-HFRT had a non-statistically significant trend towards higher LC (2-year 81.0% vs. 72.3%, 3-year 77.3% vs 52.3%, HR 0.53 [95% CI 0.26-1.09], p = 0.09) and OS (2-year 61.3% vs. 44.8%, 3-year 44.9% vs 33.9%, HR 0.68 [95% CI 0.41-1.11], p = 0.13) compared to those with C-HFRT. Similar findings were noted among those with lung-only treatment. Among those with ultra-central tumors, patients with DE-HFRT had statistically significantly higher LC (2-year 86.6% vs 71.2%, 3-year 86.6% vs 42.2%, HR 0.26 [95% CI 0.08-0.84] p = 0.02) and a non-statistically significant trend towards higher OS (2-year 63.8% vs 40.0%, 3-year 46.2% vs 31.1% HR 0.55 [95% CI 0.28-1.09] p = 0.09) compared to those with C-HFRT. There was no statistically significant difference in grade 3+ toxicities between DE-HFRT and C-HFRT (15.4% vs. 10.9%, OR 1.48 [95% CI 0.47-4.61], p = 0.49).

CONCLUSION

We noted promising local control and overall survival for patients treated with 72 Gy in 18 fractions compared to 60 Gy in 15 fractions, especially among those with ultra-central tumors. Grade 3+ toxicities were not significantly higher for patients undergoing dose escalation. Hence, our findings suggest that DE-HFRT to the lung is a safe and effective treatment regimen for highly selected patients who cannot undergo SBRT.

Synthesis of Highly Dispersible Functionalized Carbon Nanotubes as Conductive Material through a Facile Drying Process for High-Power Lithium-ion Batteries

Herein, surface-functionalized carbon nanotubes (CNTs) were successfully synthesized by dry ball milling that facilitates industrial application. The optimal conditions were determined by analyzing the physicochemical characteristics of CNTs, including the content of the carboxyl group (-COOH) induced on the surface of CNTs by co-existing dry ice based on the ball milling time. Among them, 30 s ball milling (CNTs-30s) showed a high dispersibility in N-methyl-2-pyrrolidone (NMP) while retaining most carboxyl groups and maintaining the intrinsic high conductivity. In the evaluation of rate capability and 5 C/5 C cyclability applied to the Li_1+x (Ni_1-y-z Co_y Mn_z )_1-x O₂ with 60 % Ni (NCM622) cathode, CNTs-30s showed excellent performance based on a well-formed conductive network. Regarding improved dispersion properties and electrochemical performance, the optimal surface functionalization conditions, dispersibility, and electrode properties according to the processing time were analyzed; based on these, the correlation with electrochemical performance was confirmed.

Air- and Moisture Robust Surface Modification for Ni-Rich Layered Cathode Materials for Li-Ion Batteries

The mainstream of high-energy cathode development is focused on increasing the Ni-ratio in layered structured cathode materials. The increment of the Ni portion in the layered cathode material escalates not only the deliverable capacity but also the structural degradation. High-Ni layered cathodes are highly vulnerable to exposure to air that contains CO₂ and H₂ O, forming problematic residual lithium compounds at the surface. In this work, a novel air- and moisture robust surface modification is reported for LiNi_0.8 Co_0.1 Mn_0.1 O₂ (NCM811) via the sol-gel coating method that selectively coats the internal surface area of the polycrystalline morphology secondary particles. Bare-, Li₂ SnO₃ -coated and LiCoO₂ -coated NCM811 are exposed to different ambient environments (air, hot-air, and moisture-air) to systematically investigate the correlation between the internal/external coating morphology and performance degradations. The LiCoO₂ -coated NCM811s exhibit high-capacity retention after exposure to all environments, due to the internal surface coating that prevents the penetration of harmful compounds into the polycrystalline NCM811. On the other hand, the Li₂ SnO₃ -coated NCM811s exposed to the ambient environments show gradual capacity fading, implying the occurrence of internal degradation. This paper highlights the impact of the internal degradation of polycrystalline NCM811 after environmental exposure and the correct coating mechanisms required to successfully prevent it.

Analysis of Electrochemical Performance with Dispersion Degree of CNTs in Electrode According to Ultrasonication Process and Slurry Viscosity for Lithium-Ion Battery

Lithium-ion batteries (LIBs) continue to dominate the battery market with their efficient energy storage abilities and their ongoing development. However, at high charge/discharge C-rates their electrochemical performance decreases significantly. To improve the power density properties of LIBs, it is important to form a uniform electron transfer network in the cathode electrode via the addition of conductive additives. Carbon nanotubes (CNTs) with high crystallinity, high electrical conductivity, and high aspect ratio properties have gathered significant interest as cathode electrode conductive additives. However, due to the high aggregational properties of CNTs, it is difficult to form a uniform network for electron transfer within the electrode. In this study, to help fabricate electrodes with well-dispersed CNTs, various electrodes were prepared by controlling (i) the mixing order of the conductive material, binder, and active material, and (ii) the sonication process of the CNTs/NMP solution before the electrode slurry preparation. When the binder was mixed with a well sonicated CNTs/NMP solution, the CNTs uniformly adsorbed to the then added cathode material of LiNi0.6Co0.2Mn0.2O2 and were well-dispersed to form a flowing uniform network. This electrode fabrication process achieved > 98.74% capacity retention after 50 cycles at 5C via suppressed polarization at high current densities and a more reversible H1-M phase transition of the active material. Our study presents a novel design benchmark for the fabricating of electrodes applying well-dispersed CNTs, which can facilitate the application of LIBs in high current density applications.

Controlled pilot test of a translated cardiac rehabilitation education curriculum in percutaneous coronary intervention patients in a middle-income country delivered using WeChat: acceptability, engagement, satisfaction and preliminary outcomes

In China, despite the rapid increase in percutaneous coronary interventions (PCIs), cardiac rehabilitation (CR) is just burgeoning, leaving a need for comprehensive evidence-based education curricula. This pilot study assessed the acceptability of Simplified Chinese CR education delivered via booklets and videos on WeChat asynchronously and the impact on improving knowledge, risk factors, health behaviors and quality of life. In this pre-post, controlled, observational study, interested PCI patients received the 12-week intervention or usual care and WeChat without education. Participants completed validated surveys, including the Coronary Artery Disease Education-Questionnaire and Self-Management Scale. Acceptability (14 Likert-type items), engagement (minutes per week) and satisfaction were assessed in intervention participants. Ninety-six patients consented to participate (n = 49 intervention), of which 66 (68.8%) completed the follow-up assessments. Twenty-seven (77.1%) retained intervention participants engaged with the materials, rating content as highly acceptable (all means ≥4/5) and satisfactory (2.19 ± 0.48/3); those engaging more with the intervention were significantly more satisfied (P = 0.03). While participants in both groups achieved some improvements, only intervention participants had significant increases in disease-related knowledge, reductions in body mass index and triglycerides, as well as improvements in diet (all P < 0.05). In this first study validating the recently translated CR patient education intervention, acceptability and benefits have been supported.

Measurement properties of the WHO Disability Assessment Schedule 2.0 for evaluating functional status after inpatient surgery

BACKGROUND

Expert recommendations propose the WHO Disability Assessment Schedule (WHODAS) 2.0 as a core outcome measure in surgical studies, yet data on its long-term measurement properties remain limited. These were evaluated in a secondary analysis of the Measurement of Exercise Tolerance before Surgery (METS) prospective cohort.

METHODS

Participants were adults (40 years of age or older) who underwent inpatient non-cardiac surgery. The 12-item WHODAS and EQ-5DTM-3L questionnaires were administered preoperatively (in person) and 1 year postoperatively (by telephone). Responsiveness was characterized using standardized response means (SRMs) and correlation coefficients between change scores. Construct validity was evaluated using correlation coefficients between 1-year scores and comparisons of WHODAS scores across clinically relevant subgroups.

RESULTS

The analysis included 546 patients. There was moderate correlation between changes in WHODAS and various EQ-5DTM subscales. The strongest correlation was between changes in WHODAS and changes in the functional domains of the EQ-5D-3L-for example, mobility (Spearman's rho 0.40, 95 per cent confidence interval [c.i.] 0.32 to 0.48) and usual activities (rho 0.45, 95 per cent c.i. 0.30 to 0.52). When compared across quartiles of EQ-5D index change, median WHODAS scores followed expected patterns of change. In subgroups with expected functional status changes, the WHODAS SRMs ranged from 'small' to 'large' in the expected directions of change. At 1 year, the WHODAS demonstrated convergence with the EQ-5D-3L functional domains, and good discrimination between patients with expected differences in functional status.

CONCLUSION

The WHODAS questionnaire has construct validity and responsiveness as a measure of functional status at 1 year after major surgery.

Development of High-Energy Anodes for All-Solid-State Lithium Batteries Based on Sulfide Electrolytes

All-solid-state Li batteries (ASSBs) promise better performance and higher safety than the current liquid-based Li-ion batteries (LIBs). Sulfide ASSBs have been extensively studied and considerably advanced in recent decades. Research on identifying suitable cathode materials for sulfide ASSBs is currently well established, with great progress being made in the commercialization of layered cathodes in the liquid-based LIBs. Research on anode materials for sulfide ASSBs is of great importance for enhancing the battery energy density. However, it seems that little has been published that summarizes studies of anode materials for sulfide ASSBs and suggests future research directions. Thus, within this Minireview, we aim to provide an overview of previous and current research focused on anode materials for sulfide ASSBs and to suggest a future research direction for developing suitable anode systems for sulfide ASSBs.

Micron-Sized SiOx-Graphite Compound as Anode Materials for Commercializable Lithium-Ion Batteries

The electrode concept of graphite and silicon blending has recently been utilized as the anode in the current lithium-ion batteries (LIBs) industry, accompanying trials of improvement of cycling life in the commercial levels of electrode conditions, such as the areal capacity of approximately 3.3 mAh/cm² and volumetric capacity of approximately 570 mAh/cm³. However, the blending concept has not been widely explored in the academic reports, which focused mainly on how much volume expansion of electrodes could be mitigated. Moreover, the limitations of the blending electrodes have not been studied in detail. Therefore, herein we investigate the graphite blending electrode with micron-sized SiO_x anode material which is one of the most broadly used Si anode materials in the industry, to approach the commercial and practical view. Compared to the silicon micron particle blending electrode, the SiO_x blending electrode showed superior cycling performance in the full cell test. To elucidate the cause of the relatively less degradation of the SiO_x blending electrode as the cycling progressed in full-cell, the electrode level expansion and the solid electrolyte interphase (SEI) thickening were analyzed with various techniques, such as SEM, TEM, XPS, and STEM-EDS. We believe that this work will reveal the electrochemical insight of practical SiO_x-graphite electrodes and offer the key factors to reducing the gap between industry and academic demands for the next anode materials.

Feasibility and preliminary efficacy of the LEAD trial: a cluster randomized controlled lifestyle intervention to improve hippocampal volume in older adults at-risk for dementia

BACKGROUND

Healthy diet and exercise are associated with reduced risk of dementia in older adults. The impact of diet and exercise interventions on brain health is less consistent, especially with dietary interventions which rely on varying approaches. Our objective was to evaluate the feasibility and preliminary efficacy of a 6-month intervention combining exercise with a novel dietary counseling approach to improve hippocampal volume among older adults at-risk for dementia.

METHODS

Participants with vascular risk factors and subjective cognitive decline or early mild cognitive impairment were cluster randomized in groups of 3-4 to the diet intervention (DIET) or control education (ED) group. All participants engaged in 1 h of supervised exercise per week and additional exercise at home. DIET involved 1 h per week of group-based dietary counseling comprising education, goal setting, and strategy training. ED involved 1 h per week of group-based brain health education classes. Our primary outcome was change in hippocampal volume from baseline to 6 months. Secondary outcomes included changes in cognitive function, blood biomarkers, diet, and fitness. Recruitment challenges and early discontinuation of the trial due to COVID-19 necessitated a revised focus on feasibility and preliminary efficacy.

RESULTS

Of 190 older adults contacted, 14 (7%) were eligible and enrolled, constituting 21% of our recruitment target. All participants completed the intervention and attended 90% of exercise and DIET/ED sessions on average. All 6-month assessments prior to COVID-19 were completed but disruptions to in-person testing resulted in incomplete data collection. No serious adverse events occurred and all participants expressed positive feedback about the study. Preliminary findings did not identify any significant changes in hippocampal volume; however, substantial improvements in diet and HbA1c were observed with DIET compared to ED (d = 1.75 and 1.07, respectively).

CONCLUSIONS

High adherence and retention rates were observed among participants and preliminary findings illustrate improvements in diet quality and HbA1c. These results indicate that a larger trial is feasible if difficulties surrounding recruitment can be mitigated.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT03056508 .

Low-density lipoprotein cholesterol goal attainment and treatment patterns in a cohort of &gt;143,000 patients with atherosclerotic cardiovascular disease in Ontario, Canada

Background/Introduction

Limited real-world data are available on attainment of low-density lipoprotein cholesterol (LDL-C) treatment goals in patients with atherosclerotic cardiovascular disease (ASCVD) in Canada.

Purpose

A retrospective observational study was conducted to describe types of ASCVD events/procedures, time between events and use of lipid lowering treatment (LLT) in patients who did not achieve LDL-C goal.

Methods

Patients in Ontario ≥65 years with a primary ASCVD event/procedure between 1 Apr 2005 and 31 Mar 2016, treated with an LLT and with index and follow up LDL-C values were identified from claims data at the Institute for Clinical Evaluative Sciences data repository. Patients were assessed over a 1-year follow up period for LDL-C goal attainment (&lt;2.0 mmol/L or 50% reduction from index LDL-C) and analysed by LLT and by index event type.

Results

Overall, 28% of 143,302 patients ≥65 years on LLT failed to attain LDL-C goal at follow up (Figure). The proportion of patients failing to achieve LDL-C goal decreased from 35% to 22% over the 11-year study period. Mean time between index and follow up LDL-C (based on lowest score &gt;2 weeks and up to 1 year after index LDL-C) was 203±97 days. When analysed by low-, moderate- or high-intensity statin, 57%, 30%, and 22% of patients failed to achieve LDL-C goal at follow up, respectively.

Conclusions

In this study, more than 1 in 4 patients with ASCVD in Ontario failed to achieve guideline recommended LDL-C goal despite treatment. In particular, ∼1 in 3 patients with cerebral and peripheral arterial disease were not at goal. An opportunity exists to better manage these high risk ASCVD patients with further statin intensification and additional LLTs

This study made use of de-identified data from the ICES Data Repository, which is managed by the Institute for Clinical Evaluative Sciences with support from its funders and partners: Canada's Strategy for Patient-Oriented Research (SPOR), the Ontario SPOR Support Unit, the Canadian Institutes of Health Research and the Government of Ontario. The opinions, results and conclusions reported are those of the authors. No endorsement by ICES or any of its funders or partners is intended or should be inferred. Parts of this material are based on data and/or information compiled and provided by CIHI. However, the analyses, conclusions, opinions and statements expressed in the material are those of the author(s), and not necessarily those of CIHI

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Amgen Canada Inc.

Differences in lipid treatment patterns in women versus men in a large cohort of patients with atherosclerotic cardiovascular disease in Ontario, Canada

Background/Introduction

The prevalence of ischaemic heart disease is lower in women vs men in Canada. Studies have shown that women are more likely to be underdiagnosed and less likely to receive guideline-recommended treatments than men. Women receiving lipid-lowering therapies (LLTs) are also less likely to attain treatment goals vs men.

Purpose

We analysed use of LLTs and attainment of low-density lipoprotein cholesterol (LDL-C) treatment goals in a recent longitudinal cohort of patients with ASCVD with public drug coverage in Ontario to describe differences observed between female and male patients.

Methods

Patients ≥65 years with a primary ASCVD event/procedure between 1 Apr 2005 and 31 Mar 2016, treated with an LLT and with index and follow up LDL-C values were identified from claims data at the Institute for Clinical Evaluative Sciences data repository. Patients were assessed over a 1 year follow up period for LDL-C goal attainment (&lt;2.0 mmol/L or 50% reduction from index LDL-C as per Canadian Cardiovascular Society Guidelines) and analysed by LLT category.

Results

143,302 patients with ASCVD ≥65 years on LLTs were identified of which 41% were female. A higher proportion of female vs male patients were prescribed low (3% vs 2%) and medium intensity statins (51% vs 44%) compared with high intensity statins (43% vs 52%). A higher proportion of women failed to attain LDL-C goal compared to men (33% vs 24%) (Figure). When analysed by low, moderate or high intensity statin, 65%, 35%, and 27% of female patients and 49%, 25% and 19% of male patients failed to attain LDL-C goal at follow up.

Conclusions

In this retrospective study, women with a diagnosis of ASCVD were more frequently treated with low/moderate intensity statins whereas men were more frequently treated with high intensity statins. Approximately 2 of 3 women and 3 of 4 men receiving statin treatment attained LDL-C goal during the 1-year follow up period. Overall, there appear to be treatment differences between female and male patients with ASCVD, with males receiving higher intensity statin therapy and attaining LDL-C goal more frequently. Further research is needed to determine why these discrepancies exist.

This study made use of de-identified data from the ICES Data Repository, which is managed by the Institute for Clinical Evaluative Sciences with support from its funders and partners: Canada's Strategy for Patient-Oriented Research (SPOR), the Ontario SPOR Support Unit, the Canadian Institutes of Health Research and the Government of Ontario. The opinions, results and conclusions reported are those of the authors. No endorsement by ICES or any of its funders or partners is intended or should be inferred. Parts of this material are based on data and/or information compiled and provided by CIHI. However, the analyses, conclusions, opinions and statements expressed in the material are those of the author(s), and not necessarily those of CIHI.

Figure 1

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Amgen Canada Inc

Advances and Prospects of Sulfide All-Solid-State Lithium Batteries via One-to-One Comparison with Conventional Liquid Lithium Ion Batteries

Owing to the safety issue of lithium ion batteries (LIBs) under the harsh operating conditions of electric vehicles and mobile devices, all-solid-state lithium batteries (ASSLBs) that utilize inorganic solid electrolytes are regarded as a secure next-generation battery system. Significant efforts are devoted to developing each component of ASSLBs, such as the solid electrolyte and the active materials, which have led to considerable improvements in their electrochemical properties. Among the various solid electrolytes such as sulfide, polymer, and oxide, the sulfide solid electrolyte is considered as the most promising candidate for commercialization because of its high lithium ion conductivity and mechanical properties. However, the disparity in energy and power density between the current sulfide ASSLBs and conventional LIBs is still wide, owing to a lack of understanding of the battery electrode system. Representative developments of ASSLBs in terms of the sulfide solid electrolyte, active materials, and electrode engineering are presented with emphasis on the current status of their electrochemical performances, compared to those of LIBs. As a rational method to realizing high energy sulfide ASSLBs, the requirements for the sulfide solid electrolytes and active materials are provided along through simple experimental demonstrations. Potential future research directions in the development of commercially viable sulfide ASSLBs are suggested.

Critical Role of Cations in Lithium Sites on Extended Electrochemical Reversibility of Co-Rich Layered Oxide

Only a very limited amount of the high theoretical energy density of LiCoO₂ as a cathode material has been realized, due to its irreversible deterioration when more than 0.6 mol of lithium ions are extracted. In this study, new insights into the origin of such low electrochemical reversibility, namely the structural collapse caused by electrostatic repulsion between oxygen ions during the charge process are suggested. By incorporating the partial cation migration of LiNiO₂ , which produces a screen effect of cations in the 3b-Li site, the phase distortion of LiCoO₂ is successfully delayed which in turn expands its electrochemical reversibility. This study elucidates the relationship between the structural reversibility and electrochemical behavior of layered cathode materials and enables new design of Co-rich layered materials for cathodes with high energy density.

Characteristics and costs of multidrug-resistant tuberculosis in-patient care in the United States, 2005-2007

OBJECTIVE

A population-based study of 135 multidrug-resistant tuberculosis (MDR-TB) patients reported to the Centers for Disease Control and Prevention (CDC) during 2005-2007 found 73% were hospitalized. We analyzed factors associated with hospitalization.

METHODS

We assessed statistically significant multivariable associations with US in-patient TB diagnosis, frequency of hospitalization, length of hospital stay, and in-patient direct costs to the health care system.

RESULTS

Of 98 hospitalized patients, 83 (85%) were foreign-born. Blacks, diabetics, or smokers were more likely, and patients with disseminated disease less likely, to receive their TB diagnosis while hospitalized. Patients aged ⩾65 years, those with the acquired immune-deficiency syndrome (AIDS), or with private insurance, were hospitalized more frequently. Excluding deaths, length of stay was greater for patients aged ⩾65 years, those with extensively drug-resistant TB (XDR-TB), those residing in Texas, those with AIDS, those who were unemployed, or those who had TB resistant to all first-line medications vs. others. Average hospitalization cost per XDR-TB patient (US$285 000) was 3.5 times that per MDR-TB patient (US$81 000), in 2010 dollars. Hospitalization episode costs for MDR-TB rank third highest and those for XDR-TB highest among the principal diagnoses.

CONCLUSIONS

Hospitalization was common and remains a critical care component for patients who were older, had comorbidities, or required complex management due to XDR-TB. MDR-TB in-patient costs are among the highest for any disease.

High-Performance Heterostructured Cathodes for Lithium-Ion Batteries with a Ni-Rich Layered Oxide Core and a Li-Rich Layered Oxide Shell

The Ni-rich layered oxides with a Ni content of >0.5 are drawing much attention recently to increase the energy density of lithium-ion batteries. However, the Ni-rich layered oxides suffer from aggressive reaction of the cathode surface with the organic electrolyte at the higher operating voltages, resulting in consequent impedance rise and capacity fade. To overcome this difficulty, we present here a heterostructure composed of a Ni-rich LiNi0.7Co0.15Mn0.15O2 core and a Li-rich Li1.2-x Ni0.2Mn0.6O2 shell, incorporating the advantageous features of the structural stability of the core and chemical stability of the shell. With a unique chemical treatment for the activation of the Li2MnO3 phase of the shell, a high capacity is realized with the Li-rich shell material. Aberration-corrected scanning transmission electron microscopy (STEM) provides direct evidence for the formation of surface Li-rich shell layer. As a result, the heterostructure exhibits a high capacity retention of 98% and a discharge-voltage retention of 97% during 100 cycles with a discharge capacity of 190 mA h g-1 (at 2.0-4.5 V under C/3 rate, 1C = 200 mA g-1).

Considering Critical Factors of Li-rich Cathode and Si Anode Materials for Practical Li-ion Cell Applications

In order to keep pace with increasing energy demands for advanced electronic devices and to achieve commercialization of electric vehicles and energy-storage systems, improvements in high-energy battery technologies are required. Among the various types of batteries, lithium ion batteries (LIBs) are among the most well-developed and commercialized of energy-storage systems. LIBs with Si anodes and Li-rich cathodes are one of the most promising alternative electrode materials for next-generation, high-energy batteries. Si and Li-rich materials exhibit high reversible capacities of <2000 mAh g(-1) and >240 mAh g(-1) , respectively. However, both materials have intrinsic drawbacks and practical limitations that prevent them from being utilized directly as active materials in high-energy LIBs. Examples for Li-rich materials include phase distortion during cycling and side reactions caused by the electrolyte at the surface, and for Si, large volume changes during cycling and low conductivity are observed. Recent progress and important approaches adopted for overcoming and alleviating these drawbacks are described in this article. A perspective on these matters is suggested and the requirements for each material are delineated, in addition to introducing a full-cell prototype utilizing a Li-rich cathode and Si anode.

Carbon-Coated Core-Shell Fe-Cu Nanoparticles as Highly Active and Durable Electrocatalysts for a Zn-Air Battery

Understanding the interaction between a catalyst and oxygen has been a key step in designing better electrocatalysts for the oxygen reduction reaction (ORR) as well as applying them in metal-air batteries and fuel cells. Alloying has been studied to finely tune the catalysts' electronic structures to afford proper binding affinities for oxygen. Herein, we synthesized a noble-metal-free and nanosized transition metal CuFe alloy encapsulated with a graphitic carbon shell as a highly efficient and durable electrocatalyst for the ORR in alkaline solution. Theoretical models and experimental results demonstrated that the CuFe alloy has a more moderate binding strength for oxygen molecules as well as the final product, OH(-), thus facilitating the oxygen reduction process. Furthermore, the nitrogen-doped graphitic carbon-coated layer, formed catalytically under the influence of iron, affords enhanced charge transfer during the oxygen reduction process and superior durability. These benefits were successfully confirmed by realizing the catalyst application in a mechanically rechargeable Zn-air battery.

Superior long-term energy retention and volumetric energy density for Li-rich cathode materials

Li-rich materials are considered the most promising for Li-ion battery cathodes, as high energy densities can be achieved. However, because an activation method is lacking for large particles, small particles must be used with large surface areas, a critical drawback that leads to poor long-term energy retention and low volumetric energy densities. Here we propose a new material engineering concept to overcome these difficulties. Our material is designed with 10 μm-sized secondary particles composed of submicron scaled flake-shaped primary particles that decrease the surface area without sacrificing rate capability. A novel activation method then overcomes the previous limits of Li-rich materials with large particles. As a result, we attained high average voltage and capacity retention in turn yielding excellent energy retention of 93% during 600 cycles. This novel and unique approach may furthermore open the door to new material engineering methods for high-performance cathode materials.