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1.
BMC Surg ; 24(1): 12, 2024 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-38172770

RESUMO

BACKGROUND: Bilateral acetabular fracture is a very rare presentation among the trauma patients, as the pattern and the degree of the forces required to fracture both acetabula is very unique. The primary purpose of this study is to report a series of adult patients presenting with post-traumatic bilateral acetabular fracture without any history of pathological or metabolic bone disease. PATIENTS AND METHODS: In this retrospective study, 18 cases of traumatic bilateral acetabular fracture were included. There was predominance of both column (four patients on left and six on right) followed by anterior column (two patients left and four on right) and posterior wall (three patients left and right). They were treated surgically through open reduction and internal fixation. All cases were followed up for at least 13 months. Matta's criteria were used for radiological evaluation on plain radiographs. Functional outcome was evaluated using the Merle d'Aubigne and postel score at final follow-up. RESULTS: No patients were lost during the follow-up period; there was one case of surgical site infection. There were three cases of postoperative osteoarthritis, one case of heterotrophic ossification, one case of persistent sciatic nerve palsy and one case of lateral femoral cutaneous nerve palsy. The radiological evaluation according to Matta's criteria revealed anatomic reduction in 12 patients, imperfect reduction in three patients while other three patients had poor reduction. According to modified Merle d'Aubigne and Postel score, 10 cases were rated as excellent, five cases as good and three cases presented fair (one case) to poor (two cases) results. CONCLUSION: We report an unusual case series of bilateral acetabular fracture successfully managed surgically with good clinical outcome. With the increasing incidence of route traffic accidents, such cases would probably be recurrent in the upcoming years.


Assuntos
Fraturas Ósseas , Fraturas do Quadril , Fraturas da Coluna Vertebral , Adulto , Humanos , Estudos Retrospectivos , Resultado do Tratamento , Fraturas Ósseas/complicações , Fraturas Ósseas/cirurgia , Acetábulo/cirurgia , Acetábulo/lesões , Fixação Interna de Fraturas/métodos
2.
Cureus ; 15(10): e47415, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-38021714

RESUMO

Surgical clip migration post-laparoscopic cholecystectomy is a rare but important complication to consider in patients presenting with biliary obstruction. Titanium surgical clips are widely used in laparoscopic surgery to ligate vessels and ducts and are particularly important in laparoscopic cholecystectomy to ligate the cystic duct. More common complications associated with clips involve dislodgement, however, there are reported cases of migration into visceral structures causing an obstruction. We describe a case that demonstrated an acute migration of surgical clips into the common bile duct (CBD) within a three-week period, which occurred 32 years after laparoscopic cholecystectomy, likely attributed to erosion. On the patient's first presentation, she had acute pancreatitis with a CT demonstrating clips in the correct position. Three weeks later, the patient presented a second time with acute cholangitis and the repeat CT demonstrated the clips in the CBD. We hypothesize that the erosion of the bile duct is due to the pressure effects from either intra-abdominal organ movements or subtle clip movements, and eventually, persistent erosion leading to intra-ductal migration of the clips with the passage of the clips along the path of least resistance into the CBD, resulting in biliary obstruction. Management included standard treatment for biliary obstruction with intravenous broad-spectrum antibiotics and endoscopic retrograde cholangiopancreatography with excellent outcomes.

3.
Proc Natl Acad Sci U S A ; 120(41): e2310714120, 2023 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-37782794

RESUMO

The future application of Li metal batteries (LMBs) at scale demands electrolytes that endow improved performance under fast-charging and low-temperature operating conditions. Recent works indicate that desolvation kinetics of Li+ plays a crucial role in enabling such behavior. However, the modulation of this process has typically been achieved through inducing qualitative degrees of ion pairing into the system. In this work, we find that a more quantitative control of the ion pairing is crucial to minimizing the desolvation penalty at the electrified interface and thus the reversibility of the Li metal anode under kinetic strain. This effect is demonstrated in localized electrolytes based on strongly and weakly bound ether solvents that allow for the deconvolution of solvation chemistry and structure. Unexpectedly, we find that maximum degrees of ion pairing are suboptimal for ultralow temperature and high-rate operation and that reversibility is substantially improved via slight local dilution away from the saturation point. Further, we find that at the optimum degree of ion pairing for each system, weakly bound solvents still produce superior behavior. The impact of these structure and chemistry effects on charge transfer are then explicitly resolved via experimental and computational analyses. Lastly, we demonstrate that the locally optimized diethyl ether-based localized-high-concentration electrolytes supports kinetic strained operating conditions, including cycling down to -60 °C and 20-min fast charging in LMB full cells. This work demonstrates that explicit, quantitative optimization of the Li+ solvation state is necessary for developing LMB electrolytes capable of low-temperature and high-rate operation.

4.
J Glob Antimicrob Resist ; 35: 271-278, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37816434

RESUMO

OBJECTIVES: The study aims to monitor dihydroartemisinin-piperaquine (DHA-PPQ) efficacy in Plasmodium falciparum and detect molecular markers associated with its resistance. METHODS: The World Health Organization's standard protocol for therapeutic efficacy studies (TES) was performed from 2014 to 2018; integrated drug efficacy surveillance (iDES) was performed from from 2019 to July 2023. Molecular markers were detected by polymerase chain reaction. The association between gene mutations and delayed parasite clearance was analysed by multivariate logistic regression analysis. RESULTS: A total of 226 P. falciparum patients were enrolled in the TES from 2014 to 2018, and 26 patients with P. falciparum from Africa were recruited in the iDES from 2019 to July 2023. The PCR-adjusted clinical and parasitological cure rate was 93.7% (95% CI: 92.6-99.5%) in the TES and 96.2% (95% CI: 80.4-99.9%) in the iDEs. Twelve mutants and an overall 55.0% prevalence of pfK13 mutations were detected. Of them, G533S, C447R, C447S, N458Y, C469Y, and A676D were first detected out along the China-Myanmar border. Referred to the wild strain, adjusted odds ratios of treatment failure for G533S, N458Y, and P574L by 42 days were 7.54 (95% CI: 1.605-45.86), 13.68 (95% CI: 1.95-130.72), and 89.00 (95% CI: 1.98-2482.1), respectively. CONCLUSION: The efficacy of DHA-PPQ from 2014 to 2018 declined in comparison with 2003 to 2013, but it is still effective for treatment of P. falciparum malaria. Results of the iDES indicate a risk of artemisinin resistance in Africa. G533S, N458Y, and P574L are associated with delayed parasite clearance and treatment failure.


Assuntos
Antimaláricos , Malária Falciparum , Humanos , Plasmodium falciparum/genética , Antimaláricos/uso terapêutico , Antimaláricos/farmacologia , Mianmar , Prevalência , Malária Falciparum/tratamento farmacológico , China
5.
BMC Surg ; 23(1): 251, 2023 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-37612690

RESUMO

OBJECTIVES: Surgical management of comminuted patella fractures remains a major challenge for the surgeon. We developed a suture reduction (SR) technique to better preserve the comminuted patella. The study aimed to compare the suture reduction technique with conventional reduction (CR) technique in the management of comminuted patellar fractures using the modified Kirschner-wire (K-wire) tension band. METHODS: From May 2016 to September 2020, a total of 75 patients with comminuted patellar fracture were reviewed retrospectively. Among these cases, 35 patients were in the suture reduction group with a mean age of 52 years, while 40 patients were in the conventional reduction group with a mean age of 53 years. All cases were closed fractures. Comminuted patellar fractures were classified as type 34-C3 according to the AO/OTA classification. Radiographs of the knee were obtained at routine follow-up to evaluate the reduction quality and fracture union. Clinical outcomes including range of motion (ROM), visual analog scale (VAS), Lysholm, and Böstman grading scales were measured at the last follow-up. Postoperative complications were also recorded. RESULTS: The average time from injury to surgery was 5.4 days in suture reduction group and 3.7 days in conventional reduction group (p < 0.05). The surgical time of suture reduction group was less than that of conventional reduction group, but there was no significant difference (p = 0.110) regarding surgical time between the two groups. The average blood loss in suture reduction group was 42.9 ml, while the average blood loss in conventional reduction group was 69.3 ml (p < 0.001). There was no difference regarding fracture union, ROM and knee function score (Lysholm score and Böstman scale) between the two groups. The complication rates were 17.1% in suture reduction group and 12.5% in conventional reduction group respectively (p > 0.05). CONCLUSIONS: In the treatment of comminuted patellar fractures with modified K-wire tension band, the use of suture reduction technique can shorten the surgical time, reduce the surgical trauma, and obtain satisfactory results. This new surgical technique may be particularly effective in management of comminuted patellar fractures when patellectomy would otherwise be considered.


Assuntos
Fixação de Fratura , Fraturas Cominutivas , Traumatismos do Joelho , Técnicas de Sutura , Humanos , Pessoa de Meia-Idade , Fraturas Cominutivas/cirurgia , Traumatismos do Joelho/diagnóstico por imagem , Traumatismos do Joelho/cirurgia , Estudos Retrospectivos , Patela/lesões , Patela/cirurgia , Fixação de Fratura/métodos
6.
Sci Rep ; 13(1): 12570, 2023 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-37532829

RESUMO

This study aimed to evaluate the efficacy of perioperative intravenous TXA in reducing blood loss in pelvic and acetabular fracture patients managed surgically. The study included 306 consecutive patients, divided as: group I, 157 patients who did not receive perioperative infusion of TXA and group II, 149 patients who received perioperative TXA. The perioperative blood test results and complication rates were compared between the two groups. The average perioperative hematocrit was higher during the preoperative period than during the first, second and third postoperative day in both groups. In the estimated blood loss between the two groups, there was a significant difference of 1391 (± 167.49) ml in group I and 725 (± 403.31) ml in group II respectively (p = 0.02). No significant difference was seen in the total of intraoperative transfusion units as well as in the total units of blood transfused. There was a reduced level of postoperative hemoglobin (9.28 ± 17.88 g/dl in group I and 10.06 ± 27.57 g/dl in group II compared to the values obtained in preoperative investigations (10.4 ± 2.37 g/dl in group I and 11.4 ± 2.08 g/dl in group II); with a significant difference in postoperative transfusion rates (p = 0.03). Therefore, the use of TXA effectively reduces the risk of intraoperative bleeding during open management of pelvic and acetabular fractures.


Assuntos
Antifibrinolíticos , Fraturas do Quadril , Ácido Tranexâmico , Humanos , Antifibrinolíticos/uso terapêutico , Perda Sanguínea Cirúrgica/prevenção & controle , Fraturas do Quadril/cirurgia , Transfusão de Sangue , Administração Intravenosa , Estudos Retrospectivos
7.
bioRxiv ; 2023 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-37425937

RESUMO

Connections between neurons can be mapped by acquiring and analyzing electron microscopic (EM) brain images. In recent years, this approach has been applied to chunks of brains to reconstruct local connectivity maps that are highly informative, yet inadequate for understanding brain function more globally. Here, we present the first neuronal wiring diagram of a whole adult brain, containing 5×107 chemical synapses between ~130,000 neurons reconstructed from a female Drosophila melanogaster. The resource also incorporates annotations of cell classes and types, nerves, hemilineages, and predictions of neurotransmitter identities. Data products are available by download, programmatic access, and interactive browsing and made interoperable with other fly data resources. We show how to derive a projectome, a map of projections between regions, from the connectome. We demonstrate the tracing of synaptic pathways and the analysis of information flow from inputs (sensory and ascending neurons) to outputs (motor, endocrine, and descending neurons), across both hemispheres, and between the central brain and the optic lobes. Tracing from a subset of photoreceptors all the way to descending motor pathways illustrates how structure can uncover putative circuit mechanisms underlying sensorimotor behaviors. The technologies and open ecosystem of the FlyWire Consortium set the stage for future large-scale connectome projects in other species.

8.
Nano Lett ; 23(15): 7062-7069, 2023 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-37522917

RESUMO

Nonaqueous fluidic transport and ion solvation properties under nanoscale confinement are poorly understood, especially in ion conduction for energy storage and conversion systems. Herein, metal-organic frameworks (MOFs) and aprotic electrolytes are studied as a robust platform for molecular-level insights into electrolyte behaviors in confined spaces. By employing computer simulations, along with spectroscopic and electrochemical measurements, we demonstrate several phenomena that deviate from the bulk, including modulated solvent molecular configurations, aggregated solvation structures, and tunable transport mechanisms from quasi-solid to quasi-liquid in functionalized MOFs. Technologically, taking advantage of confinement effects may prove useful for addressing stability concerns associated with volatile organic electrolytes while simultaneously endowing ultrafast transport of solvates, resulting in improved battery performance, even at extreme temperatures. The molecular-level insights presented here further our understanding of structure-property relationships of complex fluids at the nanoscale, information that can be exploited for the predictive design of more efficient electrochemical systems.

9.
bioRxiv ; 2023 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-37425808

RESUMO

The fruit fly Drosophila melanogaster combines surprisingly sophisticated behaviour with a highly tractable nervous system. A large part of the fly's success as a model organism in modern neuroscience stems from the concentration of collaboratively generated molecular genetic and digital resources. As presented in our FlyWire companion paper 1 , this now includes the first full brain connectome of an adult animal. Here we report the systematic and hierarchical annotation of this ~130,000-neuron connectome including neuronal classes, cell types and developmental units (hemilineages). This enables any researcher to navigate this huge dataset and find systems and neurons of interest, linked to the literature through the Virtual Fly Brain database 2 . Crucially, this resource includes 4,552 cell types. 3,094 are rigorous consensus validations of cell types previously proposed in the hemibrain connectome 3 . In addition, we propose 1,458 new cell types, arising mostly from the fact that the FlyWire connectome spans the whole brain, whereas the hemibrain derives from a subvolume. Comparison of FlyWire and the hemibrain showed that cell type counts and strong connections were largely stable, but connection weights were surprisingly variable within and across animals. Further analysis defined simple heuristics for connectome interpretation: connections stronger than 10 unitary synapses or providing >1% of the input to a target cell are highly conserved. Some cell types showed increased variability across connectomes: the most common cell type in the mushroom body, required for learning and memory, is almost twice as numerous in FlyWire as the hemibrain. We find evidence for functional homeostasis through adjustments of the absolute amount of excitatory input while maintaining the excitation-inhibition ratio. Finally, and surprisingly, about one third of the cell types proposed in the hemibrain connectome could not yet be reliably identified in the FlyWire connectome. We therefore suggest that cell types should be defined to be robust to inter-individual variation, namely as groups of cells that are quantitatively more similar to cells in a different brain than to any other cell in the same brain. Joint analysis of the FlyWire and hemibrain connectomes demonstrates the viability and utility of this new definition. Our work defines a consensus cell type atlas for the fly brain and provides both an intellectual framework and open source toolchain for brain-scale comparative connectomics.

10.
Front Pediatr ; 11: 1169581, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37260793

RESUMO

Purpose: Fractures of the femoral neck account for less than 1% of pediatric and adolescent fractures. Due to the high incidence of complications, and the age of the patients, the choice of fixation approach remains controversial among orthopedic surgeons. This study aimed to evaluate the postoperative outcomes and complications of femoral neck fracture in adolescents with open physis, following transphyseal fixation using a combined cannulated cancellous screw and Kirschner wire fixation. Methods: Data of 19 patients aged between 12 and 19 years from January 2010 to January 2021 were retrospectively studied. The follow-up period was 1-11 years (5.83 ± 3.76 years). The variables of interest including demographic and clinical variables [age, BMI, gender, side of injury, fracture classification, operation time, time to surgery, and length of hospital stay (LOS)], postoperative outcomes, and complications (fracture healing time, nonunion, coxa vara, osteoarthritis, avascular necrosis, screw loosening, and femoral shortening) were analyzed. The assessment of the hip function was done on the final follow-up using the Ratliff scoring system. Results: There was a male predominance of 76%; the mean age was 16.14 ± 1.57 years and the most frequent mechanism of injury was fall from a height. Delbet type II and III were the most encountered. The mean intraoperative time was 54.71 ± 7.85 min, the LOS was 8.34 ± 1.81days, and the time to surgery was 2.60 ± 1.16 days; the fracture healing time was 3.31 ± 1.04 months. The postoperative complications encountered were coxa vara osteoarthritis, spontaneous dislocation, and neck shortening. Clinical assessment revealed good results in 89% of patients and fair results in 11% of patients. Conclusion: Transphyseal fixation using cannulated cancellous screw combined with Kirschner wire in our patients provided acceptable results. Thus, this approach can be a viable alternative in the management of adolescent femoral neck fracture with open physis.

11.
Front Surg ; 10: 1164032, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37206352

RESUMO

Purpose: The management of floating knee injuries is still controversial and challenging for trauma specialists. This study aims to evaluate the incidence of the floating knee in lower limb trauma, analyzing the challenges in its management, and factors affecting clinical outcomes. Methods: In this mono-center retrospective study, 36 consecutive patients were included. All individuals were diagnosed with an ipsilateral fracture of the femur and tibia, managed surgically according to their fracture pattern (Fraser classification), and the severity of the injury. The timing for each operation was determined based on the general condition of the patient and the local physiological condition of soft tissues. The patients' clinical outcomes were finally evaluated based on their Karlstrom and Olerud scores and were categorized as excellent, good, acceptable, fair, or poor. Results: In this study, the mean follow-up period was 51.39 ± 16.02 months (11-130 months). Incidence of the floating knee was 2.32% in all lower limb traumas. From this number, 16 patients suffered from floating knee injury in the left lower extremity, and 18 in the right lower limb, while in 2 patients the condition was bilateral. The most common injury mechanism was road traffic accidents, accounting for 28 (77.78%) cases. The outcome was as follows; Excellent to good results in 22 (61.11%) cases, acceptable results in 2 (5.56%) cases, and fair to poor results in 12 (33.33%) cases according to the Karlström-Olerud scoring system. The most frequent early complications were wound infection and deep venous thrombosis in 5 (13.88%) of the cases. The most common late complication was common peroneal nerve palsy recorded in 2 (5.56%) cases. Conclusion: The presence of important concomitant injuries to the floating knee together with poor soft tissue conditions constituted important factors influencing possible management options and may have led to poorer clinical outcomes.

12.
BMC Musculoskelet Disord ; 24(1): 70, 2023 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-36703126

RESUMO

BACKGROUND: The fractures of femoral neck account for 50% among hip fractures with around 3%-10% occurring in younger population of below 65 years. The newly introduced FNS as management approach appears to be a potential alternative to the traditional CCS. The aim of this study was to compare the clinical efficacy and outcome of the femoral neck system (FNS) and the cannulated cancellous screw (CCS) in the treatment of femoral neck fractures in adult below 65 years of age. METHODS: Data of 114 patients between 18-65 years, admitted in our department for femoral neck fracture from January 2019 to March 2021 were retrospectively studied and ranged into two groups based on the surgical methods: FNS group (56 patients) and CCS group (58 patients). The variables of interest including demographic and clinical variables (age, gender, fracture mechanism, injury side and classification), perioperative parameters(operation time, intraoperative bleeding, incision length and hospitalization time), postoperative outcomes and complications (fracture healing time, nonunion rate, femoral neck avascular necrosis, aseptic screw loosening and the Harris Hip Score), were analyzed and compared between the two groups. RESULTS: All 114 patients presented satisfactory reduction and were followed-up for a period of 12 to 36 months (mean 27 ± 2.07 months); there were no significant differences between both groups in terms of age, gender, fracture classification, side of injury, mechanism of injury, the operative time, intraoperative blood loss and the hospital length of stay. However, the fracture healing time between FNS group and CCS group was statistically significant (p < 0.05), respectively 2.86 ± 0.77 and 5.10 ± 0.81 months. The significant differences were also found in terms of numbers of fluoroscopies 8.34 ± 1.38 Vs 17.72 ± 2.19, the HHS 87.80 ± 1.92 Vs 84.28 ± 2.24, postoperative complications 8 (14.28%) Vs 26 (44.82) respectively in FNS and CCS group. CONCLUSION: FNS presented satisfactory outcomes had significantly lower complications rate, therefore, can be one of the alternatives for internal implantation devices in treatment of femoral neck fracture in non-geriatric population.


Assuntos
Fraturas do Colo Femoral , Colo do Fêmur , Adulto , Humanos , Estudos Retrospectivos , Fixação Interna de Fraturas/efeitos adversos , Fraturas do Colo Femoral/cirurgia , Resultado do Tratamento , Parafusos Ósseos
13.
Adv Mater ; 35(3): e2207932, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36284477

RESUMO

Lithium fluorinated-carbon (Li/CFx ) is one of the most promising chemistries for high-energy-density primary energy-storage systems in applications where rechargeability is not required. Though Li/CFx demonstrates high energy density (>2100 Wh kg-1 ) under ambient conditions, achieving such a high energy density when exposed to subzero temperatures remains a challenge, particularly under high current density. Here, a liquefied gas electrolyte with an anion-pair solvation structure based on dimethyl ether with a low melting point (-141 °C) and low viscosity (0.12 mPa s, 20 °C), leading to high ionic conductivity (>3.5 mS cm-1 ) between -70 and 60 °C is reported. Besides that, through systematic X-ray photoelectron spectroscopy integrated with transmission electron microscopy characterizations, the interface of CFx is evaluated for low-temperature performance. The fast transport and anion-pairing solvation structure of the electrolyte are concluded to bring about reduced charge-transfer resistance at low temperatures, which results in significantly enhanced performance of Li/CFx cells (1690 Wh kg-1 , -60 °C based on active materials). Utilizing 50 mg cm-2 loading electrodes, the Li/CFx still displays 1530 Wh kg-1 at -60 °C. This work provides insights into the electrolyte design that may overcome the operational limits of batteries in extreme environments.

14.
Proc Natl Acad Sci U S A ; 119(28): e2200392119, 2022 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-35787034

RESUMO

All-climate temperature operation capability and increased energy density have been recognized as two crucial targets, but they are rarely achieved together in rechargeable lithium (Li) batteries. Herein, we demonstrate an electrolyte system by using monodentate dibutyl ether with both low melting and high boiling points as the sole solvent. Its weak solvation endows an aggregate solvation structure and low solubility toward polysulfide species in a relatively low electrolyte concentration (2 mol L-1). These features were found to be vital in avoiding dendrite growth and enabling Li metal Coulombic efficiencies of 99.0%, 98.2%, and 98.7% at 23 °C, -40 °C, and 50 °C, respectively. Pouch cells employing thin Li metal (50 µm) and high-loading sulfurized polyacrylonitrile (3.3 mAh cm-2) cathodes (negative-to-positive capacity ratio = 2) output 87.5% and 115.9% of their room temperature capacity at -40 °C and 50 °C, respectively. This work provides solvent-based design criteria for a wide temperature range Li-sulfur pouch cells.

15.
Sci Adv ; 8(7): eabm7723, 2022 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-35179957

RESUMO

Variations in neuronal connectivity occur widely in nervous systems from invertebrates to mammals. Yet, it is unclear how neuronal variability originates, to what extent and at what time scales it exists, and what functional consequences it might carry. To assess inter- and intraindividual neuronal variability, it would be ideal to analyze the same identified neuron across different brain hemispheres and individuals. Here, using genetic labeling and electron microscopy connectomics, we show that an identified inhibitory olfactory local interneuron, TC-LN, exhibits extraordinary variability in its glomerular innervation patterns. Moreover, TC-LN's innervation of the VL2a glomerulus, which processes food signals and modulates mating behavior, is sexually dimorphic, is influenced by female's courtship experience, and correlates with food intake in mated females. Mating also affects output connectivity of TC-LN to specific local interneurons. We propose that mating-associated variability of TC-LNs regulates how food odor is interpreted by an inhibitory network to modulate feeding.

17.
Nat Commun ; 12(1): 3395, 2021 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-34099643

RESUMO

Confining molecules in the nanoscale environment can lead to dramatic changes of their physical and chemical properties, which opens possibilities for new applications. There is a growing interest in liquefied gas electrolytes for electrochemical devices operating at low temperatures due to their low melting point. However, their high vapor pressure still poses potential safety concerns for practical usages. Herein, we report facile capillary condensation of gas electrolyte by strong confinement in sub-nanometer pores of metal-organic framework (MOF). By designing MOF-polymer membranes (MPMs) that present dense and continuous micropore (~0.8 nm) networks, we show significant uptake of hydrofluorocarbon molecules in MOF pores at pressure lower than the bulk counterpart. This unique property enables lithium/fluorinated graphite batteries with MPM-based electrolytes to deliver a significantly higher capacity than those with commercial separator membranes (~500 mAh g-1 vs. <0.03 mAh g-1) at -40 °C under reduced pressure of the electrolyte.

18.
Nat Energy ; 20212021.
Artigo em Inglês | MEDLINE | ID: mdl-33717504

RESUMO

Lithium metal batteries (LMBs) hold the promise to pushing cell level energy densities beyond 300 Wh kg-1 while operating at ultra-low temperatures (< -30°C). Batteries capable of both charging and discharging at these temperature extremes are highly desirable due to their inherent reduction of external warming requirements. Here we demonstrate that the local solvation structure of the electrolyte defines the charge-transfer behavior at ultra-low temperature, which is crucial for achieving high Li metal coulombic efficiency (CE) and avoiding dendritic growth. These insights were applied to Li metal full cells, where a high-loading 3.5 mAh cm-2 sulfurized polyacrylonitrile (SPAN) cathode was paired with a one-fold excess Li metal anode. The cell retained 84 % and 76 % of its room temperature capacity when cycled at -40 and -60 °C, respectively, which presented stable performance over 50 cycles. This work provides design criteria for ultra-low temperature LMB electrolytes, and represents a defining step for the performance of low-temperature batteries.

19.
Chem Commun (Camb) ; 56(64): 9114-9117, 2020 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-32666984

RESUMO

A novel lithium bis(fluorosulfonyl)imide in a methyl propionate/fluoroethylene carbonate (LiFSI MP/FEC) electrolyte was designed for high compatibility with the Li metal and sulfurized polyacrylonitrile (SPAN). The resulting Li||SPAN cells can charge and discharge at -20 °C and -40 °C with over 91% and 78% room temperature capacity retention.

20.
Angew Chem Int Ed Engl ; 58(52): 18892-18897, 2019 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-31654444

RESUMO

Improving the extremely low temperature operation of rechargeable batteries is vital to the operation of electronics in extreme environments, where systems capable of high-rate discharge are in short supply. Herein, we demonstrate the holistic design of dual-graphite batteries, which circumvent the sluggish ion-desolvation process found in typical lithium-ion batteries during discharge. These batteries were enabled by a novel electrolyte, which simultaneously provides high electrochemical stability and ionic conductivity at low temperature. The dual-graphite cells, when compared to industry-type graphite ∥ LiCoO2 full-cells demonstrated an 11 times increased capacity retention at -60 °C for a 10 C discharge rate, indicative of the superior kinetics of the "dual-ion" storage mechanism. These trends are further supported by galvanostatic intermittent titration technique (GITT) and electrochemical impedance spectroscopy (EIS) measurements at reduced temperature. This work provides a new design strategy for extreme low-temperature batteries.

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