FABRICATION AND ELECTROCHEMICAL PERFORMANCE OF LiFePO4/Ga-LLZO/Li ALL-SOLID-STATE LITHIUM BUTTON CELL

An all-solid-state Lithium button cell with Ga-doped Li7La3Zr2O12 (Ga-LLZO) as solid electrolyte, LiFePO4-based as cathode, and Li metal as anode has been successfully fabricated and characterized. The solid electrolyte was first optimized to obtain a high total conductivity. Different compositions of Li7-3xGaxLa3Zr2O12, where x =0, 0.1, 0.2, and 0.3. Li7La3Zr2O12 (LLZO) were synthesized using solid-state reaction and were characterized for its structural, morphological, electrical conductivity properties. XRD patterns of all sintered samples showed that all of the major peaks can be indexed to a cubic-phased garnet LLZO. SEM images revealed a densified sintered samples with relative densities of about 90% for all samples. Among the different studied compositions, the Ga-doped LLZO with x = 0.1 achieved the highest total conductivity of about 2.03 x 10-4 Scm-1 at 25oC, with an activation energy of 0.31 eV. From this solid electrolyte, an all-solid-state Lithium battery, 2032 button cell, was fabricated using LiFePO4-based cathode and Lithium metal as the anode. Charging and discharging characteristics were performed at 1C, 0.5C, and 0.2C rates. The results showed a good retention of coloumbic efficiency even after 50 cycles of charge and discharge. The capacity retention is about 15-20% after 50 cycles. The best performance of the coin cell battery revealed an initial specific discharging capacity of about 140 mAh/g using C/5 rate.

3D localization for subcentimeter-sized devices

The vision of tracking small IoT devices runs into the reality of localization technologies---today it is difficult to continuously track objects through walls in homes and warehouses on a coin cell battery. Although Wi-Fi and ultra-wideband radios can provide tracking through walls, they do not last more than a month on small coin and button cell batteries because they consume tens of milliwatts of power. We present the first localization system that consumes microwatts of power at a mobile device and can be localized across multiple rooms in settings such as homes and hospitals. To this end, we introduce a multiband backscatter prototype that operates across 900 MHz, 2.4 GHz, and 5 GHz and can extract the backscatter phase information from signals that are below the noise floor. We build subcentimeter-sized prototypes that consume 93 μW and could last five to ten years on button cell batteries. We achieved ranges of up to 60 m away from the AP and accuracies of 2, 12, 50, and 145 cm at 1, 5, 30, and 60 m, respectively. To demonstrate the potential of our design, we deploy it in two real-world scenarios: five homes in a metropolitan area and the surgery wing of a hospital in patient pre-op and post-op rooms as well as storage facilities.

Battery-Related Injuries in Children and Adults

The aim of the current study was to analyze the circumstances behind battery injuries, including the mode of injuries experienced (e.g., a shock or consumption), as well as the battery types and products most frequently involved in battery injuries. The National Electronic Injury Surveillance System (NEISS), a probability sample of US hospitals that collects information from emergency room (ER) visits related to a consumer product, was utilized. Injury data from the NEISS database was coded to identify a) the accident mode that led to the injury, b) the battery type involved, and c) the product that was powered by the battery or charger, if available. The data revealed that battery-related injuries were most often associated with (1) children consuming button cell batteries associated with toys and other household objects, and (2) adults becoming burned when handling vehicle batteries. Surprisingly, injuries associated with rechargeable batteries were the least frequent; however, when burns occurred, they were predominantly related to e- cigarettes, as well as vehicles. Results are discussed in terms of general exposure to specific battery types and products analyzing these battery types within each age group.

Chemical Burn Injury in the Scrotal Area Caused by Button Cell Battery: A Case Report

: Here we reported a one-year-old infant with tissue damage in the scrotum area, in which a small button cell battery had been found in his diaper. Evidence suggested that the lesion was caused by contact with the leaky battery with the scrotal skin. The treatment procedure was prescribed by a dermatologist. The healing process was tracked over the examination times. After two months, the site of the lesion showed complete remission. The findings suggested that in such cases, after removing the chemical agent, blisters, and necrotic tissues, therapeutic measures should be performed similarly to the thermal burns.

Fabrication of Compositionally Gradient Anode Functional Layer for Proton Conducting Fuel Cell at Intermediate Temperatures: A Preliminary Study

In this work, an anode-supported button cell was fabricated with compositionally gradient (CG) NiO-BaCe0.54Zr0.36Y0.1O2.95 (NiO-BCZY) anode functional layer (AFL). The button cell has a configuration of NiO-BCZY (50:50) | NiO-BCZY (30:70) | NiO-BCZY (10:90) | BCZY | LSCF. All powder materials were synthesized using a sol-gel method. Firstly, NiO-BCZY anode substrate was fabricated using dry-pressing method. Next, NiO-BCZY CG-AFL and BCZY electrolyte thin film were spin-coated on the anode substrate and lastly the La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) cathode was spin-coated on the electrolyte thin film. The microstructure of the fabricated button cell with good adhesion between all the layers, thin and dense electrolyte layer, and gradient increase in density of materials from anode substrate to electrolyte were observed using Scanning Electron Microscopy (SEM). Cell’s performance in terms of resistivity was evaluated using Electrochemical Impedance Spectroscopy (EIS) and conductivity meter using four-point probe method. Values of ohmic (Ro) and polarization resistance (Rp) of the cell are 7.3 and 2.4 Ωcm2 at 700 °C, respectively. The lower resistance values obtained compared to our previous work on a conventional 3-layers BCZY-based single button cell (Ro = 9.6 and Rp = 7.8 Ωcm2 at 700 °C) confirmed the functionality of GC-AFL in enhancing the cell’s performance. This preliminary result shows that simple deposition technique of CG-AFL plays a significant role in the optimization of PCFC button cell designs and electrochemical performance.

Development of an Automatic Body Mass Index Measurement Machine

The potential occurrence of certain illnesses can be easily diagnosed through measurements of some health indicators. One of such parameters is the Body Mass Index (BMI). BMI is simply the ratio of mass (kg) of a body to the square of its height (m2). This research presents the design and construction of an automated BMI measurement machine for medical purposes. It consists of three major units: the weighing unit (5 – 200 kg); height-measuring unit (0.02 – 2 m) and the processing unit. The weighing unit is made up of load button cell and load cell amplifier while the height-measuring unit consists of ultrasonic sensor. The analog differential output voltage from load cell is connected to arduino microcontroller via a Programmable Gain Amplifier (PGA) integrated with Analogue-to-Digital Converter (ADC). The two units are connected to an open source arduino uno which computes mass-to-body ratio and sends the output results (mass, height and BMI) to the liquid crystal display (LCD). The weighing system was calibrated against a precision digital weighing system and it gave a correlation of 0.99. The height measurement was also compared with manual height measurement using a tape rule which gave a correlation of 0.97. The developed Instrument is cost effective and has high positive correlation with the standards (weighing scale and tape rule), it is therefore recommended for the measurement of weight, height and BMI. Keywords— load button cell, load cell amplifier, ultrasonic, body mass index, arduino uno