50 Years of Image Analysis

Lithium-ion batteries (LIBs), with relatively high energy density and power density, have been considered as a vital energy source in our daily life, especially in electric vehicles. However, energy density and safety related to thermal runaways are the main concerns for their further applications. In order to deeply understand the development of high energy density and safe LIBs, we comprehensively review the safety features of LIBs and the failure mechanisms of cathodes, anodes, separators and electrolyte. The corresponding solutions for designing safer components are systematically proposed. Additionally, the in situ or operando techniques, such as microscopy and spectrum analysis, the fiber Bragg grating sensor and the gas sensor, are summarized to monitor the internal conditions of LIBs in real time. The main purpose of this review is to provide some general guidelines for the design of safe and high energy density batteries from the views of both material and cell levels. Safety of lithium-ion batteries (LIBs) with high energy density becomes more and more important in the future for EVs development. The safety issues of the LIBs are complicated, related to both materials and the cell level. To ensure the safety of LIBs, in-depth understanding of the safety features, precise design of the battery materials and real-time monitoring/detection of the cells should be systematically considered. Here, we specifically summarize the safety features of the LIBs from the aspects of their voltage and temperature tolerance, the failure mechanism of the LIB materials and corresponding improved methods. We further review the in situ or operando techniques to real-time monitor the internal conditions of LIBs.

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Building Safe Lithium-Ion Batteries for Electric Vehicles: A Review

Multiferroic heterostructures can be synthesized by integrating monolithic ferroelectric and magnetic materials, with interfacial coupling between electric polarization and magnetization, through the exchange of elastic, electric, and magnetic energy. Although the nature of the interfaces remains to be unraveled, such cross coupling can be utilized to manipulate the magnetization (or polarization) with an electric (or magnetic) field, known as a converse (or direct) magnetoelectric effect. It can be exploited to significantly improve the performance of or/and add new functionalities to many existing or emerging devices such as memory devices, tunable microwave devices, sensors, etc. The exciting technological potential, along with the rich physical phenomena at the interface, has sparked intensive research on multiferroic heterostructures for more than a decade. Here, we summarize the most recent progresses in the fundamental principles and potential applications of the interface-based magnetoelectric effect in multiferroic heterostructures, and present our perspectives on some key issues that require further study in order to realize their practical device applications.

Multiferroic Heterostructures Integrating Ferroelectric and Magnetic Materials.

Wearables as medical technologies are becoming an integral part of personal analytics, measuring physical status, recording physiological parameters, or informing schedule for medication. These continuously evolving technology platforms do not only promise to help people pursue a healthier life style, but also provide continuous medical data for actively tracking metabolic status, diagnosis, and treatment. Advances in the miniaturization of flexible electronics, electrochemical biosensors, microfluidics, and artificial intelligence algorithms have led to wearable devices that can generate real-time medical data within the Internet of things. These flexible devices can be configured to make conformal contact with epidermal, ocular, intracochlear, and dental interfaces to collect biochemical or electrophysiological signals. This article discusses consumer trends in wearable electronics, commercial and emerging devices, and fabrication methods. It also reviews real-time monitoring of vital signs using biosensors, stimuli-responsive materials for drug delivery, and closed-loop theranostic systems. It covers future challenges in augmented, virtual, and mixed reality, communication modes, energy management, displays, conformity, and data safety. The development of patient-oriented wearable technologies and their incorporation in randomized clinical trials will facilitate the design of safe and effective approaches.

/pdf/wearables-in-medicine-5azfm8fp5w.pdf

Wearables in Medicine

Particle-reinforced metal matrix nanocomposites fabricated by selective laser melting : a state of the art review

In-situ temperature measurement in lithium ion battery by transferable flexible thin film thermocouples

Insertable thin film thermocouples for in situ transient temperature monitoring in ultrasonic metal welding of battery tabs

Procеss physіcs undеrstаndіng, rеаl tіmе monіtorіng аnd control of vаrіous mаnufаcturіng processes, such аs bаttеry mаnufаcturіng, аrе crucіаl for product quаlіty аssurаncе. Whіlе ultrаsonіc wеldіng hаs bееn usеd for joining bаttеries in еlеctrіc vеhіclеs, the welding physics and process attributes, such as the heat generation and heat flow during the joining process, іs stіll not wеll understood lеаdіng to tіmе-consumіng trіаl-аnd-еrror bаsеd procеss optіmіzаtіon. Thіs study іs to іnvеstіgаtе thеrmаl phеnomеnа (і.е. transient tеmpеrаturе аnd hеаt flux) by using mіcro thіn fіlm thеrmocouplе (TFTC) аnd thіn fіlm thеrmopіlе (TFTP) аrrаys (referred to as micro sensors in this report) аt thе vеry vіcіnіty of thе ultrаsonіc wеldіng spot. Micro sеnsors were first fаbrіcаtеd on the buss bаrs. A series of experiments were then conducted to investigate the dynamic heat generation during the welding process. Expеrіmеntаl rеsults showеd that TFTCs еnаblеd thе sеnsіng of trаnsіеnt tеmpеrаturеs wіth much hіghеr spаtіаl аnd tеmporаl rеsolutіons thаn convеntіonаl thеrmocouplеs. It was further found that the TFTPs were more sensitive to thе trаnsіеnt heat generation process during welding thаn TFTCs. Morе sіgnіfіcаntly, the hеаt flux chаngе rаtе was found to be able to provіdе better іnsіght for the process. It provided evidence indicating thаt thе ultrаsonіc welding procеss іnvolvеs thrее dіstіnct stаgеs, і.е., frіctіon hеаtіng, plаstіc work аnd dіffusіon bondіng stаgеs. Thе hеаt flux chаngе rаtе thus hаs sіgnіfіcаnt potеntіаl to identify the in-situ welding quality, in the context of welding procеss monіtorіng аnd control of ultrаsonіc wеldіng procеss. The weld samples were examed using scanning electron microscopy (SEM) and energy dispersive X-ray spectropy (EDS) to study the material interactions at the bonding interface as a function of weld time, and have successfully validated the proposed three-stage welding theory. As a case study, TFTCs were fabricated on Si wafers for sensor insertion units, which were successfully inserted into a pre-machined slot in the welding anvil as a temperature sensing device. Dynamic temperature rises during welding were successfully measured with excellent repeatability.

Transient Temperature and Heat Flux Measurement in Ultrasonic Joining of Battery Tabs Using Thin-Film Microsensors

Fundamental Study on Laser Interactions With Nanoparticles-Reinforced Metals—Part II: Effect of Nanoparticles on Surface Tension, Viscosity, and Laser Melting

Jingzhou Zhao

Papers

In-situ temperature measurement in lithium ion battery by transferable flexible thin film thermocouples

Insertable thin film thermocouples for in situ transient temperature monitoring in ultrasonic metal welding of battery tabs

Transient Temperature and Heat Flux Measurement in Ultrasonic Joining of Battery Tabs Using Thin-Film Microsensors

Fundamental Study on Laser Interactions With Nanoparticles-Reinforced Metals—Part II: Effect of Nanoparticles on Surface Tension, Viscosity, and Laser Melting

Phase control in immiscible Zn-Bi alloy by tungsten nanoparticles