Do beta-blockers reduce negative intrusive thoughts and anxiety in cancer survivors? - An emulated trial.

BACKGROUND: High rates of negative intrusive thoughts have been reported among cancer patients. Prevalent users of beta-blocker therapy have reported lower levels of cancer related intrusive thoughts than non-user. The aim of this study is to investigate if initiation of beta-blocker therapy reduces the prevalence and severity of intrusive thoughts (co-primary endpoints) and the prevalence of anxiety, depressed mood, and low quality of life (secondary endpoints) in cancer survivors. METHODS: Data on patient-reported outcomes from three cohort studies of Swedish patients diagnosed with colon, prostate or rectal cancer were combined with data on beta-blocker prescriptions retrieved from the Swedish Prescribed Drug Register. Two randomized controlled trials were emulated. Trial 1 had follow-up 1 year after diagnosis, trial 2 had follow-up 2 years after diagnosis, baseline in both trials was 12 months before follow-up. Those who initiated beta-blocker therapy between baseline and follow-up was assigned Active group, those who did not was assigned Control group. All endpoints were analysed using Bayesian ordered logistic regression. RESULTS: Trial 1 consisted of Active group, n = 59, and Control group, n = 3936. Trial 2 consisted of Active group, n = 87, and Control group, n = 3132. The majority of participants were men, 83% in trial 1 and 94% in trial 2. The prevalence and severity of intrusive thoughts were lower in the Active group in trial 1, but no significant differences between groups were found in either trial. The prevalence of depressed mood, worse quality of life and periods of anxiety were higher in the Active group in both trials with significant differences for quality of life in trial 1 and anxiety in trial 2. CONCLUSIONS: The emulated trials demonstrated no evidence of a protective effect of beta-blocker therapy against intrusive thoughts. The Active group had reduced quality of life and elevated anxiety compared to the Control group. TRIAL REGISTRATION: The three cohort studies were registered at isrctn.com/clinicaltrials.gov (ISRCTN06393679, NCT02530593 and NCT01477229).

Digital twins and Bayesian dynamic borrowing: Two recent approaches for incorporating historical control data.

Recent years have seen an increasing interest in incorporating external control data for designing and evaluating randomized clinical trials (RCT). This may decrease costs and shorten inclusion times by reducing sample sizes. For small populations, with limited recruitment, this can be especially important. Bayesian dynamic borrowing (BDB) has been a popular choice as it claims to protect against potential prior data conflict. Digital twins (DT) has recently been proposed as another method to utilize historical data. DT, also known as PROCOVA™, is based on constructing a prognostic score from historical control data, typically using machine learning. This score is included in a pre-specified ANCOVA as the primary analysis of the RCT. The promise of this idea is power increase while guaranteeing strong type 1 error control. In this paper, we apply analytic derivations and simulations to analyze and discuss examples of these two approaches. We conclude that BDB and DT, although similar in scope, have fundamental differences which need be considered in the specific application. The inflation of the type 1 error is a serious issue for BDB, while more evidence is needed of a tangible value of DT for real RCTs.

Short-term results in a population based study indicate advantage for minimally invasive rectal cancer surgery versus open.

BACKGROUND: The aim of this study was to determine if minimally invasive surgery (MIS) for rectal cancer is non-inferior to open surgery (OPEN) regarding adequacy of cancer resection in a population based setting. METHODS: All 9,464 patients diagnosed with rectal cancer 2012-2018 who underwent curative surgery were included from the Swedish Colorectal Cancer Registry. PRIMARY OUTCOMES: Positive circumferential resection margin (CRM < 1 mm) and positive resection margin (R1). Non-inferiority margins used were 2.4% and 4%. SECONDARY OUTCOMES: 30- and 90-day mortality, clinical anastomotic leak, re-operation < 30 days, 30- and 90-day re-admission, length of stay (LOS), distal resection margin < 1 mm and < 12 resected lymph nodes. Analyses were performed by intention-to-treat using unweighted and weighted multiple regression analyses. RESULTS: The CRM was positive in 3.8% of the MIS group and 5.4% of the OPEN group, risk difference -1.6% (95% CI -1.623, -1.622). R1 was recorded in 2.8% of patients in the MIS group and in 4.4% of patients in the OPEN group, risk difference -1.6% (95% CI -1.649, -1.633). There were no differences between the groups in adjusted unweighted and weighted analyses. All analyses demonstrated decreased mortality and re-admissions at 30 and 90 days as well as shorter LOS following MIS. CONCLUSIONS: In this population based setting MIS for rectal cancer was non-inferior to OPEN regarding adequacy of cancer resection with favorable short-term outcomes.

The Relationship between Ionic Conductivity and Solvation Structures of Localized High-Concentration Fluorinated Electrolytes for Lithium-Ion Batteries.

Localized high-concentration electrolytes (LHCEs) combine a diluent with a high-concentration electrolyte, offering promising properties. The ions, solvent, and diluent interact to form complex heterogeneous liquid structures, where high salt concentration clusters are embedded in the diluent. Optimizing LHCEs for desired electrolyte properties like high ionic conductivity, low viscosity, and effective solid electrolyte interphase (SEI) formation ability within the vast chemical and compositional design space requires deeper understanding and theoretical guidance. We investigated the structures and conductivities of LHCEs based on a fluorinated solvent with two different diluents at varying concentrations. 2,2,3,3-Tetrafluoropropyl trifluoroacetate (TFPTFA) enters the solvation cluster due to its stronger Li-ion interactions, whereas 1,1,2,2-tetrafluoroethyl 2,2,2-trifluoroethyl ether (TFETFE) enters only at extremely high diluent concentrations. The ionic conductivity increases with decreasing diluent concentrations, with a slope change during cluster percolation. Overall, TFETFE demonstrates higher effectiveness than TFPTFA, forming higher local salt concentration clusters and resulting in higher ionic conductivity.

Survival in relation to time to start of curative treatment of colon cancer: A national register-based observational noninferiority study.

AIM: There are ample discussions regarding the timing of treatment, especially in the era after Covid that caused delay to treatment. The aim of this study was to determine whether a delayed start to curative treatment, within 29-56 days after a diagnosis of colon cancer, was noninferior to starting treatment within 28 days, with regard to all-cause mortality. METHOD: This is a national register-based observational noninferiority study, with a noninferiority margin of hazard ratio (HR) 1.1, including all patients treated with curative intent for colon cancer in Sweden between 2008 and 2016. The primary outcome was all-cause mortality. Secondary outcomes were length of hospital stay, readmissions and reoperations within 1 year after surgery. Exclusion criteria were emergency surgery, disseminated disease at diagnosis, missing diagnosis date and treatment for another cancer 5 years before colon cancer diagnosis. RESULTS: A total of 20 836 individuals were included. A period of 29-56 days from diagnosis to start of curative treatment was noninferior versus starting treatment within 28 days for the primary outcome of all-cause mortality (HR 0.95, 95% CI 0.89-1.00). Starting treatment within 29-56 days was associated with a shorter length of stay (average 9.2 vs. 10 days) but a higher risk of reoperation compared to within 28 days. Post hoc analyses demonstrated that surgical modality was driving survival rather than time to treatment. Overall survival was greater after laparoscopic surgery (HR 0.78, 95% CI 0.69-0.88). CONCLUSION: For patients with colon cancer, a period of up to 56 days from diagnosis to the start of curative treatment did not lead to worse overall survival.

Two-Dimensional Siloxene Nanosheets: Impact of Morphology and Purity on Electrochemistry.

Two-dimensional (2D) siloxene (Si6O3H6) has shown promise as a negative electrode material for Li-ion batteries due to its high gravimetric capacity and superior mechanical properties under (de)lithiation compared to bulk Si. In this work, we prepare purified siloxene nanosheets through the removal of bulk Si contaminants, use ultrasonication to control the lateral size and thickness of the nanosheets, and probe the effects of the resulting morphology and purity on the electrochemistry. The thin siloxene nanosheets formed after 4 h of ultrasonication deliver an average capacity of 810 mA h/g under a 1000 mA/g rate over 200 cycles with a capacity retention of 76%. Interestingly, the purified siloxene shows lower initial capacity but superior capacity retention over extended cycling. The 2D morphology benefit is illustrated where the parent siloxene nanosheet morphology and structure were largely maintained based on operando optoelectrochemistry, in situ Raman, ex situ scanning electron microscopy, and ex situ transmission electron microscopy. Furthermore, the purified siloxene-based electrode free from crystalline Si impurity experiences the least expansion upon (de)lithiation as visualized by cross-section electron microscopy of samples recovered post-cycling.

Salvage radiotherapy after radical prostatectomy: functional outcomes in the LAPPRO trial after 8-year follow-up.

OBJECTIVE: Radical prostatectomy reduces mortality among patients with localized prostate cancer, however up to 35% of patients will experience biochemical recurrence, often treated with salvage radiotherapy. The objective of the study was to investigate long-term effects of salvage radiotherapy. METHODS: A prospective, controlled, non-randomized trial at 14 Swedish center's including 4,003 patients scheduled for radical prostatectomy 2008-2011. A target trial emulation approach was used to identify eligible patients that was treated with salvage radiotherapy. The control group received no salvage radiotherapy. Outcomes were assessed by patient questionnaires on ordinal scales and statistical group comparisons were made using ordered logit regression with adjustment for baseline outcome and confounding factors. The primary endpoints were bowel, urinary and sexual function and bothering due to dysfunction at 8 years. RESULTS: Eleven percent (330/3,139) of the analyzed study population received salvage radiotherapy. Fecal leakage, leakage of mucus and hematochezia were more common after receiving salvage radiotherapy compared with the control group; 4.5% versus 2.6% odds ratio (95% confidence interval [CI]): (1.90 [1.38; 2.62]), 6.8% versus 1.5% 4.14 (2.98; 5.76) and 8.6% versus 1.2% 4.14 (2.98; 5.76), respectively. Urinary incontinence, erectile dysfunction and hematuria were more common after receiving salvage radiotherapy, 34% versus 23% 2.23 (2.65; 3.00), 65% versus 57% 1.65 (1.18; 2.29) and 16% versus 1.6% 11.17 (5.68; 21.99), respectively. CONCLUSION: Salvage radiotherapy was associated with increased risk for fecal leakage, hematochezia, urinary incontinence and hematuria. Our results emphasize the importance of selecting patients for salvage radiotherapy to avoid overtreatment and to give high quality pre-treatment information to ensure patients' preparedness for late side-effects.

Functional Outcomes of Emergency Surgery for Perforated Diverticulitis, Hinchey Grade III.

BACKGROUND: Laparoscopic lavage as a treatment for perforated diverticulitis, Hinchey III, has been found safe and feasible in randomized trials. A few studies have reported functional outcomes and quality of life as secondary outcomes. This study investigated distress associated with dysfunction of the bowel or stoma, functional outcomes, and quality of life 2-3 years after surgery in a national unselected cohort. METHODS: All patients in Sweden who underwent emergency surgery for perforated diverticulitis with purulent peritonitis (2016-2018) were invited to answer a comprehensive, study-specific questionnaire 2-3 years after the index surgery. RESULTS: Out of 499 potential patients, 226 returned the questionnaire, and 209 were included in the analysis. There was no statistically significant difference between laparoscopic lavage and resection in distress associated with dysfunction of the bowel or stoma (odds ratio [OR], 1.32 [95% CI, 0.91-1.92]; p = 0.015). Bowel dysfunction measured by the LARS score was significantly higher for the lavage group (OR, 1.65 [95% CI, 1.11-2.45]), while stoma was more frequent after resection surgery (40 vs 6%). CONCLUSIONS: Patients experienced long-term distress from bodily dysfunction after emergency surgery for perforated diverticulitis regardless of the technique used. Regular follow-up could benefit these patients. TRIAL REGISTRATION: The project was registered at ClinicalTrials.gov on 2017-11-06. Identifier: NCT03332550. Acronym: LapLav.

Short term results in a population based study indicate advantage for laparoscopic colon cancer surgery versus open.

The aim of this study was to compare LAP with OPEN regarding short-term mortality, morbidity and completeness of the cancer resection for colon cancer in a routine health care setting using population based register data. All 13,683 patients who were diagnosed 2012-2018 and underwent elective surgery for right-sided or sigmoid colon cancer were included from the Swedish Colorectal Cancer Registry and the National Patient Registry. Primary outcome was 30-day mortality. Secondary outcomes were 90-day mortality, length of hospital stay, reoperation, readmission and positive resection margin (R1). Weighted and unweighted multi regression analyses were performed. There were no difference in 30-day mortality: LAP (0.9%) and OPEN (1.3%) (OR 0.89, 95% CI 0.62-1.29, P = 0.545). The weighted analyses showed an increased 90-day mortality following OPEN, P < 0.001. Re-operations and re-admission were more frequent after OPEN and length of hospital stay was 2.9 days shorter following LAP (P < 0.001). R1 resections were significantly more common in the OPEN group in the unweighted and weighted analysis with P = 0.004 and P < 0.001 respectively. Therefore, the favourable short-term outcomes following elective LAP versus OPEN resection for colon cancer in routine health care indicate an advantage of laparoscopic surgery.

The impact of the anastomotic configuration on low anterior resection syndrome 3 years after total mesorectal excision for rectal cancer: a national cohort study.

AIM: After low anterior resection, the bowel can be anastomosed in different ways. It is not clear which configuration is optimal from a functional and complication point of view. The primary aim was to investigate the impact of the anastomotic configuration on bowel function evaluated by the low anterior resection syndrome (LARS) score. Secondarily, the impact on postoperative complications was evaluated. METHOD: All patients who had undergone low anterior resection from 2015 to 2017 were identified in the Swedish Colorectal Cancer Registry. Three years after surgery, patients were sent an extensive questionnaire and were analysed based on anastomotic configuration ('J-pouch/side-to-end anastomosis' or 'straight anastomosis'). Inverse probability weighting by propensity score was used to adjust for confounding factors. RESULTS: Among 892 patients, 574 (64%) responded, of whom 494 patients were analysed. After weighting, the anastomotic configuration had no significant impact on the LARS score (J-pouch/side-to-end OR 1.05, 95% confidence interval [CI] 0.82-1.34). The J-pouch/side-to-end anastomosis was significantly associated with overall postoperative complications (OR 1.43, 95% CI 1.06-1.95). No significant difference was seen regarding surgical complications (OR 1.14, 95% CI 0.78-1.66). CONCLUSION: This is the first study investigating the impact of the anastomotic configuration on long-term bowel function, evaluated by the LARS score, in an unselected national cohort. Our results suggested no benefit for J-pouch/side-to-end anastomosis on long-term bowel function and postoperative complication rates. The anastomotic strategy may be based upon the anatomical conditions of the patient and surgical preference.

Electron and Ion Transport in Lithium and Lithium-Ion Battery Negative and Positive Composite Electrodes.

Electrochemical energy storage systems, specifically lithium and lithium-ion batteries, are ubiquitous in contemporary society with the widespread deployment of portable electronic devices. Emerging storage applications such as integration of renewable energy generation and expanded adoption of electric vehicles present an array of functional demands. Critical to battery function are electron and ion transport as they determine the energy output of the battery under application conditions and what portion of the total energy contained in the battery can be utilized. This review considers electron and ion transport processes for active materials as well as positive and negative composite electrodes. Length and time scales over many orders of magnitude are relevant ranging from atomic arrangements of materials and short times for electron conduction to large format batteries and many years of operation. Characterization over this diversity of scales demands multiple methods to obtain a complete view of the transport processes involved. In addition, we offer a perspective on strategies for enabling rational design of electrodes, the role of continuum modeling, and the fundamental science needed for continued advancement of electrochemical energy storage systems with improved energy density, power, and lifetime.

Sick leave and predictive factors for sick leave at 12 months after breast cancer surgery in the randomized controlled physical activity trial (PhysSURG-B).

OBJECTIVE: To evaluate sick leave 12 months after breast cancer surgery, to analyze the effect of adjuvant chemotherapy and to identify predictive factors for sick leave, based on a randomized controlled trial of a non-supervised physical activity intervention (PhysSURG-B). METHODS: Sick leave days (for patients age 18-67) were collected from the Swedish Social Insurance Agency, and compared between the intervention and control arm in the trial. A random forest model was used to analyze predictive factors for sick leave, including baseline patient and tumor characteristics as well as patient-reported outcomes measuring quality of life, personality traits, pain, anxiety and depression. RESULTS: A total of 203 patients were analyzed, and when comparing intervention to control, there was no differences in sick leave days (117 vs 55 days, odds ratio 1.21; 95% CI 0.75-1.96). Adjuvant chemotherapy significantly increased days of sick leave (323 vs 42 days, odds ratio 17.3; 95% CI 9.15-34.2). Factors predicting prolonged sick leave were adjuvant chemotherapy, young age, previous mental health problems and low quality of life (measured as FACT-B score) at baseline. CONCLUSION: A non-supervised physical activity intervention had no effect on sick leave 12 months after surgery. Significantly longer sick leave was seen in patients treated by adjuvant chemotherapy. Factors predicting prolonged sick leave can be recognized at baseline and utilized when designing future interventions.

Simultaneous Elucidation of Solid and Solution Manganese Environments via Multiphase Operando Extended X-ray Absorption Fine Structure Spectroscopy in Aqueous Zn/MnO2 Batteries.

Aqueous Zn/MnO2 batteries (AZMOB) with mildly acidic electrolytes hold promise as potential green grid-level energy storage solutions for clean power generation. Mechanistic understanding is critical to advance capacity retention needed by the application but is complex due to the evolution of the cathode solid phases and the presence of dissolved manganese in the electrolyte due to a dissolution-deposition redox process. This work introduces operando multiphase extended X-ray absorption fine structure (EXAFS) analysis enabling simultaneous characterization of both aqueous and solid phases involved in the Mn redox reactions. The methodology was successfully conducted in multiple electrolytes (ZnSO4, Zn(CF3SO3)2, and Zn(CH3COO)2) revealing similar manganese coordination environments but quantitative differences in distribution of Mnn+ species in the solid and solution phases. Complementary Raman spectroscopy was utilized to identify the less crystalline Mn-containing products formed under charge at the cathodes. This was further augmented by transmission electron microscopy (TEM) to reveal the morphology and surface condition of the deposited solids. The results demonstrate an effective approach for bulk-level characterization of poorly crystalline multiphase solids while simultaneously gaining insight into the dissolved transition-metal species in solution. This work provides demonstration of a useful approach toward gaining insight into complex electrochemical mechanisms where both solid state and dissolved active materials are important contributors to redox activity.

Design principles for heterointerfacial alloying kinetics at metallic anodes in rechargeable batteries.

How surface chemistry influences reactions occurring thereupon has been a long-standing question of broad scientific and technological interest. Here, we consider the relation between the surface chemistry at interfaces and the reversibility of electrochemical transformations at rechargeable battery electrodes. Using Zn as a model system, we report that a moderate strength of chemical interaction between the deposit and the substrate-neither too weak nor too strong-enables highest reversibility and stability of the plating/stripping redox processes. Focused ion beam and electron microscopy were used to directly probe the morphology, chemistry, and crystallography of heterointerfaces of distinct natures. Analogous to the empirical Sabatier principle for chemical heterogeneous catalysis, our findings arise from competing interfacial processes. Using full batteries with stringent negative electrode-to-positive electrode capacity (N:P) ratios, we show that such knowledge provides a powerful tool for designing key materials in highly reversible battery systems based on Earth-abundant, low-cost metals such as Zn and Na.

The effect of nonsupervised physical activity before and after breast cancer surgery on quality of life: Results from a randomized controlled trial (PhysSURG-B).

BACKGROUND AND OBJECTIVE: The PhysSURG-B trial of prehabilitation before breast cancer surgery randomized patients to a nonsupervised physical activity or a control group. The effects of the intervention on short- and long-term quality of life (QoL) were examined, with a subgroup analysis of patients receiving adjuvant chemotherapy. METHODS: Female patients planned for surgery were randomly assigned to either an intervention of 30 min of self-administered physical aerobic activity daily 2 weeks before and 4 weeks after surgery or control. QoL was assessed with questionnaires at baseline, 4 weeks and 12 months postoperatively using the instruments FACT-B, RAND-36, and EQ-VAS. RESULTS: Of 354 included participants at 12 months after surgery, 287 were available for analysis. FACT- B scores at 4 weeks and 12 months showed no differences between intervention compared to control, odds ratio (OR) of 0.975 (95% confidence interval (CI) 0.636-1.495) and 0.883 (95% CI 0.581-1.342), respectively. There was no difference in EQ-VAS comparing intervention to control at 4 weeks and 12 months, respectively, OR 1.163 (95% CI 0.760-1.779) and 0.817 (95% CI 0.559-1.300). RAND-36 domains "role limitations due to physical health" and "pain" showed a decrease at 4 weeks in both groups, returning toward baseline at 12 months follow-up. The subgroup who received adjuvant chemotherapy had significantly lower QoL measured using FACT-B at 12 months compared to patients not receiving chemotherapy (OR 0.475; 95% CI 0.300-0.753). CONCLUSIONS: An intervention of non-supervised physical activity before and after surgery for breast cancer showed no effect on short or long-term QoL, compared to control. TRIAL REGISTRATION: ClinicalTrials.gov registration number: NCT02560662.

Learning curve for robot-assisted laparoscopic radical prostatectomy in a large prospective multicentre study.

OBJECTIVE: Differences in outcome after radical prostatectomy for prostate cancer can partly be explained by intersurgeon differences, where degree of experience is one important aspect. This study aims to define the learning curve of robot-assisted laparoscopic prostatectomy (RALP) regarding oncological and functional outcomes. MATERIALS AND METHODS: Out of 4003 enrolled patients in the LAPPRO trial, 3583 met the inclusion criteria, of whom 885 were operated on by an open technique. In total, 2672 patients with clinically localized prostate cancer from seven Swedish centres were operated on by RALP and followed for 8 years (LAPPRO trial). Oncological outcomes were pathology-reported surgical margins and biochemical recurrence at 8 years. Functional outcomes included patient-reported urinary incontinence and erectile dysfunction at 3, 12 and 24 months. Experience was surgeon-reported experience before and during the study. The relationship between surgeon experience and functional outcomes and surgical margin status was analysed by mixed-effects logistic regression. Biochemical recurrence was analysed by Cox regression, with robust standard errors. RESULTS: The learning curve for positive surgical margins was relatively flat, with rates of 21% for surgeons who had performed 0-74 cases and 24% for surgeons with > 300 cases. Biochemical recurrence at 4 years was 11% (0-74 cases) and 13% (> 300 cases). Incontinence was stable over the learning curve, but erectile function improved at 2 years, from 38% (0-74 cases) to 53% (> 300 cases). CONCLUSIONS: Analysis of the learning curve for surgeons performing RALP showed that erectile function improved with increasing number of procedures, which was not the case for oncological outcomes.

Multimodal electrochemistry coupled microcalorimetric and X-ray probing of the capacity fade mechanisms of Nickel rich NMC - progress and outlook.

Lithium nickel manganese cobalt oxide (NMC) is a commercially successful Li-ion battery cathode due to its high energy density; however, its delivered capacity must be intentionally limited to achieve capacity retention over extended cycling. To design next-generation NMC batteries with longer life and higher capacity the origins of high potential capacity fade must be understood. Operando hard X-ray characterization techniques are critical for this endeavor as they allow the acquisition of information about the evolution of structure, oxidation state, and coordination environment of NMC as the material (de)lithiates in a functional battery. This perspective outlines recent developments in the elucidation of capacity fade mechanisms in NMC through hard X-ray probes, surface sensitive soft X-ray characterization, and isothermal microcalorimetry. A case study on the effect of charging potential on NMC811 over extended cycling is presented to illustrate the benefits of these approaches. The results showed that charging to 4.7 V leads to higher delivered capacity, but much greater fade as compared to charging to 4.3 V. Operando XRD and SEM results indicated that particle fracture from increased structural distortions at >4.3 V was a contributor to capacity fade. Operando hard XAS revealed significant Ni and Co redox during cycling as well as a Jahn-Teller distortion at the discharged state (Ni3+); however, minimal differences were observed between the cells charged to 4.3 and 4.7 V. Additional XAS analyses using soft X-rays revealed significant surface reconstruction after cycling to 4.7 V, revealing another contribution to fade. Operando isothermal microcalorimetry (IMC) indicated that the high voltage charge to 4.7 V resulted in a doubling of the heat dissipation when compared to charging to 4.3 V. A lowered chemical-to-electrical energy conversion efficiency due to thermal energy waste was observed, providing a complementary characterization of electrochemical degradation. The work demonstrates the utility of multi-modal X-ray and microcalorimetric approaches to understand the causes of capacity fade in lithium-ion batteries with Ni-rich NMC.

The Dopamine Assisted Synthesis of MoO3/Carbon Electrodes With Enhanced Capacitance in Aqueous Electrolyte.

A capacitance increase phenomenon is observed for MoO3 electrodes synthesized via a sol-gel process in the presence of dopamine hydrochloride (Dopa HCl) as compared to α-MoO3 electrodes in 5M ZnCl2 aqueous electrolyte. The synthesis approach is based on a hydrogen peroxide-initiated sol-gel reaction to which the Dopa HCl is added. The powder precursor (Dopa)xMoOy, is isolated from the metastable gel using freeze-drying. Hydrothermal treatment (HT) of the precursor results in the formation of MoO3 accompanied by carbonization of the organic molecules; designated as HT-MoO3/C. HT of the precipitate formed in the absence of dopamine in the reaction produced α-MoO3, which was used as a reference material in this study (α-MoO3-ref). Scanning electron microscopy (SEM) images show a nanobelt morphology for both HT-MoO3/C and α-MoO3-ref powders, but with distinct differences in the shape of the nanobelts. The presence of carbonaceous content in the structure of HT-MoO3/C is confirmed by FTIR and Raman spectroscopy measurements. X-ray diffraction (XRD) and Rietveld refinement analysis demonstrate the presence of α-MoO3 and h-MoO3 phases in the structure of HT-MoO3/C. The increased specific capacitance delivered by the HT-MoO3/C electrode as compared to the α-MoO3-ref electrode in 5M ZnCl2 electrolyte in a -0.25-0.70 V vs. Ag/AgCl potential window triggered a more detailed study in an expanded potential window. In the 5M ZnCl2 electrolyte at a scan rate of 2 mV s-1, the HT-MoO3/C electrode shows a second cycle capacitance of 347.6 F g-1. The higher electrochemical performance of the HT-MoO3/C electrode can be attributed to the presence of carbon in its structure, which can facilitate electron transport. Our study provides a new route for further development of metal oxides for energy storage applications.

Interfacial Reactivity of Silicon Electrodes: Impact of Electrolyte Solvent and Presence of Conductive Carbon.

Silicon (Si) is a promising high-capacity material for lithium-ion batteries; however, its limited reversibility hinders commercial adoption. Approaches such as particle and crystallite size reduction, introduction of conductive carbon, and use of different electrolyte solvents have been explored to overcome these electrochemical limitations. Herein, operando isothermal microcalorimetry (IMC) is used to probe the influence of silicon particle size, electrode composition, and electrolyte additives fluoroethylene carbonate and vinylene carbonate on the heat flow during silicon lithiation. The IMC data are complemented by X-ray photoelectron and Raman spectroscopies to elucidate differences in solid electrolyte interphase (SEI) composition. Nanosized (∼50 nm, n-Si) and micrometer-sized (∼4 µm, µ-Si) silicon electrodes are formulated with and without amorphous carbon and electrochemically lithiated in ethylene carbonate (EC), fluoroethylene carbonate (FEC), or vinylene carbonate (VC) based electrolytes. Notably, n-Si electrodes generate 53-61% more normalized heat relative to their µ-Si counterparts, consistent with increased surface area and electrode/electrolyte reactivity. Introduction of amorphous carbon significantly alters the heat flow profile where multiple exothermic peaks and increased normalized heat dissipation are observed for all electrolyte types. Notably, the VC-containing electrolyte demonstrates the greatest normalized heat dissipation of the electrode compositions tested showing as much as a 50% increase compared to the EC or FEC counterparts. The results are relevant to the understanding of silicon negative electrode function in the presence of electrolyte additives and provide insight relative to silicon containing cell reactivity and safety.