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A solar cell is a device that can convert solar energy into electrical energy. The third generation of solar cells is Dye-Sensitized Solar Cells (DSSC). Typically, DSSC consists of a working electrode (semiconductive metal oxide), a photosensitizer, an electrolyte, and a counter electrode (platinum or carbon electrode). Among the components, a working electrode is one of the crucial components to control the electrochemical performance. This study examines variations in Ag composition in TiO2-Ag composites against efficiency using two materials and fabrication methods. First, using the solid-state method, TiO2-Ag composites were fabricated from Ag paste and TiO2 paste. The highest efficiency results were achieved at TiO2 N-RT + Ag 1%. The efficiency increased from 1.05% to 1.51% compared to TiO2 without Ag doping. Second, using the solvothermal method, TiO2-Ag composites were fabricated from AgNO3 and TiO2 particles. The highest efficiency results were obtained at TiO2 NP + Ag 0.75%. The efficiency increased from 0.82% to 1.07% compared to TiO2 without Ag doping. Furthermore, the material with the best efficiency was characterized using FTIR, XRD, and SEM to identify the material’s functional groups, phases, and morphology, respectively.

Li-ion secondary battery is highly recommended as a power source to highly advanced battery electric vehicles. Among various types, the lithium nickel cobalt aluminum oxide (NCA) battery is considered suitable for high energy and power application. In this study, the NCA cathode material LiNi0.89Co0.08Al0.03O2 was produced via the oxalate co-precipitation technique to reduce the overall production cost and process complexity. Oxalic acid and a small amount of sodium hydroxide were used as the precipitant and pH regulator, respectively. Homogenous and loose metal oxalate precipitate formation was confirmed by X-ray diffraction (XRD), scanning electron microscopy, and Fourier-transform infrared spectroscopy analysis. XRD patterns of the as-obtained micron-sized NCA showed a well-layered hexagonal structure. The electrochemical properties of the cathode in the full cell were thoroughly examined. The specific discharge capacity of the as-obtained NCA in NCA/LiPF6/graphite at a current rate of 20 mA/g was 142 mAh/g. The as-prepared NCA sample had capacity retention of 80% after being charged and discharged at 0.1 A/g for 101 cycles. Scaling up of NCA production process to 2 kg per batch was conducted and evaluation of NCA product quality was performed by material characterization. Based on the overall results and considering the overall process, such an approach is expected to be developed and improved for future large-scale production purposes.

The increasing use of lithium-ion batteries (LIBs) presents a serious environmental problem. These spent LIBs are suitable sources of metals for the production of LIB cathode active material. This study successfully recovered nickel, cobalt, and aluminum from spent LIB nickel cobalt aluminum oxide (NCA) and regenerated NCA cathode. The effect of the spent anode as a reducing agent was also investigated. The spent anode alone did not reduce the metals Ni and Co sufficiently. The leaching efficiency was only 34.8, 47.15, and 86.75% for Ni, Co, and Al, respectively, and these values did not increase with increasing citric acid concentration or the addition of ascorbic acid as a reducing agent. However, it increased significantly to 85, 90.12, and 100%, for Ni, Co, and Al, respectively, with the addition of 2% v/v H2O2. The ternary metal oxalate (TMO) precipitation of the leaching solution confirmed the synthesis of TMO from the precursor. The regenerated NCA synthesized from TMO had better electrochemical performances than those of new commercial NCA. It had a specific discharge capacity of 137 mA h/g and a retention capacity of 85.4% at 2 C after 50 cycles, whereas the new commercial had a specific discharge capacity of 133.4 mA h/g and a retention capacity of 82.6% at 1 C after 50 cycles.

The high sulfide ion polarization is known to cause increased ionic conductivity in the solid sulfide-type electrolytes. Three groups of sulfide-based solid-state electrolytes, namely, Li-P-S, Li6PS5X (X: Cl, Br, and I), and LixMPxSx (M: Sn, Si, and Al) were reviewed systematically from several aspects, such as conductivity, stability, and crystal structure. The advantages and disadvantages of each electrolyte were briefly considered and compared. The method of the preparation was presented with experimental and theoretical studies. The analysis that has been carried out showed that the solid electrolyte Li10GeP2S12 is superior to others with an ionic conductivity of 12 × 10−2 S cm−1. This conductivity is comparable to that of conventional liquid electrolytes. However, the availability and high price of Ge are the problems encountered. Furthermore, because sulfide-based solid electrolytes have low chemical stability in ambient humidity, their handling is restricted to inert gas environments. When solid sulfide electrolytes are hydrolyzed, structural changes occur and H2S gas is produced. The review’s objective includes presenting a complete knowledge of sulfide-solid electrolyte synthesis method, characteristics, such as conductivity, structure, and stability, as well as generating more efficient and targeted research in enhancing the performance of the chemical substance.

Gel polymer electrolyte (GPE) membranes of polyvinylidene fluoride-based polymer matrix of different filler types such as nano-clay, ZnO, and SiO2 extracted from fly ash is produced using the non-solvent induced phase separation method. Moreover, the electrochemical properties, electrode compatibility, and the batteries performance are investigated using these gel electrolyte membranes. It is observed that gel electrolytes with nano-clay filler exhibited more stable ionic conductivity and charge–discharge performance than those containing ZnO and SiO2 extracted from fly ash. A maximum ionic conductivity of 5.62 × 10–3 S cm−1 was obtained with the addition of 8 wt% nano-clay filler at room temperature. The LiFePO4 performance assembled with these membranes is examined using coin cells (LiFePO4/GPE/graphite). After 50 cycles with a rate of 0.2 C, the battery with a different filler retained 97.7% of its initial capacity. It should be noted that this type of filler influences the electrolyte absorption, electrochemical properties, and performance of the LiFePO4.

Batteries are a very efficient energy source used in an all-digital environment that adapts to today’s human mobility. The lithium-ion battery is one of the batteries used in various household appliances. There are some problems caused by the anode in terms of utility. This is due to high electrochemical reactivity, which can reduce battery performance. One of the innovations in lithium-ion batteries is anode-free Li-ion battery (AFLB). The working mechanism of this battery is the same as the previous Li-ion battery, but with a smaller anode capacity, so that it can reduce the volume (large) of the battery. The problem that arises is the growth of dendrites that interferes with the battery’s running mechanism, so it needs to be evaluated for its growth. The way that can be done is to modify the copper foil by adding Cu. The innovation of this research is to modify Cu-foil by adding Cu from cable waste. The research method used is leaching Cu from cable waste, followed by reducing Cu powder to form a modified Cu. This study’s data collection techniques include empirical research derived from previous studies and instrumental analysis using SEM, FTIR, and electrochemical performance tests. Electrochemical testing using a cylindrical battery with a current of 1 C (1 C = 430 mA g−1) and a voltage of 2.6–4.3 V obtained ALFB and ALFB Cu-modification batteries with a discharge capacity of 70 and 123 mA h g−1, respectively.

The objective of this study is to design a temperature measurement system based on a non-contact method using a sensor camera from a webcam. The material being measured is nickel wire given an electrical current of 4.5 A-6.5 A with an interval of 0.5 A. The temperature measurement is based upon the measurement of the average pixel value distribution of infrared (IR) electromagnetic waves emitted by the measured material, i.e.: the nickel wire. The IR waves are passed through a diffraction grating and then captured by the sensor camera consisting of red, green, and blue layers. Calculation of the temperature is conducted by way of Planckian distribution as a model for the average pixel value distribution in the IR regions producing Wien's displacement law. Results show that the IR wavelength at maximum average pixel value shifts to a shorter wavelength as the nickel wire is heated in accordance with Wien's displacement law. Moreover, the Wien's constant is recovered for the temperature calculation of the red and green layers, which shows the best model for the non-contact measurement system. However, the temperature measurement still contains a systematic error that shifts the calculated temperature in contrast to the true temperature. This systematic error may be reduced by adjusting the measurement system set-up.

LiFePO4/C cathode material is largely used in Li-ion batteries due to its low toxicity, nonhazardous and high stability features. A facile and simple approach is proposed in LiFePO4/C production using low-cost materials. The effect of carbon addition during the formation of LiFePO4/C was investigated. Based on the XRD and FTIR analyses, olivine-structured LiFePO4/C cathode material was successfully obtained via methanol-based rheological method. The SEM result showed that the material has micron-sized polyhedral shape. The electrochemical performance tests were conducted in an 18,650-type cylindrical battery. The charge–discharge performances were tested at a voltage range of 2.2–3.65 V using charge and discharge rate of 1C. Based on the charge–discharge test, LiFePO4 with 30% carbon addition has the highest specific capacity of 121 mA h/g with excellent cycle and rate performance as a result of successful carbon compositing in LiFePO4 material. This approach is promising to be adapted for mass production of LiFePO4/C.