Gas Evolution Kinetics in Overlithiated Positive Electrodes and its Impact on Electrode Design

Abstract Increasing lithium contents within the lattice of positive electrode materials is projected in pursuit of high‐energy‐density batteries. However, it intensifies the release of lattice oxygen and subsequent gas evolution during operations. This poses significant challenges for managing internal pressure of batteries, particularly in terms of the management of gas evolution in composite electrodes—an area that remains largely unexplored. Conventional assumptions postulate that the total gas evolution is estimated by multiplying the total particle count by the quantities of gas products from an individual particle. Contrarily, this investigation on overlithiated materials—a system known to release the lattice oxygen—demonstrates that loading densities and inter‐particle spacing in electrodes significantly govern gas evolution rates, leading to distinct extents of gas formation despite of an equivalent quantity of released lattice oxygen. Remarkably, this study discoveres that O2 and CO2 evolution rates are proportional to 1O2 concentration by the factor of second and first‐order, respectively. This indicates an exceptionally greater change in the evolution rate of O2 compared to CO2 depending on local 1O2 concentration. These insights pave new routes for more sophisticated approaches to manage gas evolution within high‐energy‐density batteries

Development of Artificial Neural Network System to Recommend Process Conditions of Injection Molding for Various Geometries

This study combines an artificial neural network (ANN) and a random search to develop a system to recommend process conditions for injection molding. Both simulation and experimental results are collected using a mixed sampling method that combines Taguchi and random sampling. The dataset consists of 3600 simulations and 476 experiments from 36 different molds. Each datum has five process and 15 geometry features as input and one weight feature as output. Hyper‐parameter tuning is conducted to find the optimal ANN model. Then, transfer learning is introduced, which allows the use of simultaneous experimental and simulation data to reduce the error. The final prediction model has a root mean‐square error of 0.846. To develop a recommender system, random search is conducted using the trained ANN forward model. As a result, the weight‐prediction model based on simulated data has a relative error (RE) of 0.73%, and the weight prediction using the transfer model has an RE of 0.662%. A user interface system is also developed, which can be used directly with the injection‐molding machine. This method enables the setting of process conditions that yield parts having weights close to the target, by considering only the geometry and target weight.11Yothe

Thin Metallic Heat Sink for Interfacial Thermal Management in Biointegrated Optoelectronic Devices

The applications of modern optoelectronic devices have been extended, and they now provide practical means for seamless real-time monitoring of blood flow dynamics, by being integrated with flexible and stretchable wearable sensor platform technology. However, thermal management of these devices remains limited by undesired thermal energy originating from the heating of the light-emitting diode. Specifically, the surface temperature of the optoelectronic device becomes very high compared to that of the adjacent biological tissue, causing challenges in skin–optoelectronics integration and functional deterioration of the light source. In this study, an optoelectronic module that integrates the light-emitting diode, photodetector, and a thin metallic heat sink element for sustainable in situ thermal management is developed. Experimental and computational analysis results indicate that the proposed optoelectronic device has excellent heat dissipation capabilities for thermally safe long-term usability, due to the high thermal conductivity of the device and film-type geometrical design of the embedded heat sink for skin application. The proposed optoelectronic device architecture with metallic heat sink offers an ideal option for blood flow monitoring by providing both mechanical and thermal compatibility with biological tissue suitable for long-term clinical applications. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim1

Polymeric DNase-I nanozymes targeting neutrophil extracellular traps for the treatment of bowel inflammation

Abstract Inflammatory bowel disease (IBD), including Crohn’s disease and ulcerative colitis, is a family of chronic disorders along the gastrointestinal tract. Because of its idiopathic nature, IBD does not have a fundamental cure; current available therapies for IBD are limited to prolonged doses of immunomodulatory agents. While these treatments may reduce inflammation, limited therapeutic efficacy, inconsistency across patients, and adverse side effects from aggressive medications remain as major drawbacks. Recently, excessive production and accumulation of neutrophil extracellular traps (NETs) also known as NETosis have been identified to exacerbate inflammatory responses and induce further tissue damage in IBD. Such discovery invited many researchers to investigate NETs as a potential therapeutic target. DNase-I is a natural agent that can effectively destroy NETs and, therefore, potentially reduce NETs-induced inflammations even without the use of aggressive drugs. However, low stability and rapid clearance of DNase-I remain as major limitations for further therapeutic applications. In this research, polymeric nanozymes were fabricated to increase the delivery and therapeutic efficacy of DNase-I. DNase-I was immobilized on the surface of polymeric nanoparticles to maintain its enzymatic properties while extending its activity in the colon. Delivery of DNase-I using this platform allowed enhanced stability and prolonged activity of DNase-I with minimal toxicity. When administered to animal models of IBD, DNase-I nanozymes successfully alleviated various pathophysiological symptoms of IBD. More importantly, DNase-I nanozyme administration successfully attenuated neutrophil infiltration and NETosis in the colon compared to free DNase-I or mesalamine