A Fast Approach to Obtain Layered Transition-Metal Cathode Material for Rechargeable Batteries

Li-ion batteries as a support for future transportation have the advantages of high storage capacity, a long life cycle, and the fact that they are less dangerous than current battery materials. Li-ion battery components, especially the cathode, are the intercalation places for lithium, which plays an important role in battery performance. This study aims to obtain the LiNixMnyCozO2 (NMC) cathode material using a simple flash coprecipitation method. As precipitation agents and pH regulators, oxalic acid and ammonia are widely available and inexpensive. The composition of the NMC mole ratio was varied, with values of 333, 424, 442, 523, 532, 622, and 811. As a comprehensive study of NMC, lithium transition-metal oxide (LMO, LCO, and LNO) is also provided. The crystal structure, functional groups, morphology, elemental composition and material behavior of the particles were all investigated during the heating process. The galvanostatic charge–discharge analysis was tested with cylindrical cells and using mesocarbon microbeads/graphite as the anode. Cells were tested at 2.7–4.25 V at 0.5 C. Based on the analysis results, NMC with a mole ratio of 622 showed the best characteristicd and electrochemical performance. After 100 cycles, the discharged capacity reaches 153.60 mAh/g with 70.9% capacity retention.

Forest fire detection system using wireless sensor networks and machine learning

Forest fires have become a major threat around the world, causing many negative impacts on human habitats and forest ecosystems. Climatic changes and the greenhouse effect are some of the consequences of such destruction. Interestingly, a higher percentage of forest fires occur due to human activities. Therefore, to minimize the destruction caused by forest fires, there is a need to detect forest fires at their initial stage. This paper proposes a system and methodology that can be used to detect forest fires at the initial stage using a wireless sensor network. Furthermore, to acquire more accurate fire detection, a machine learning regression model is proposed. Because of the primary power supply provided by rechargeable batteries with a secondary solar power supply, a solution is readily implementable as a standalone system for prolonged periods. Moreover, in-depth attention is given to sensor node design and node placement requirements in harsh forest environments and to minimize the damage and harmful effects caused by wild animals, weather conditions, etc. to the system. Numerous trials conducted in real tropical forest sites found that the proposed system is effective in alerting forest fires with lower latency than the existing systems.

Review—Nanomaterials Green Synthesis for High-Performance Secondary Rechargeable Batteries: Approaches, Challenges, and Perspectives

Significant climate change and variable fossil energy prices are forcing us to minimize fossil fuel consumption and develop innovative energy conversion and storage systems capable of reducing carbon dioxide emissions. Batteries are the most common form of alternative energy systems, and cathode materials are critical for their performance. Their low-rate performance and short lifespan severely hamper the efficiency of cathode materials. The adoption of nanotechnology is essential to improve the cathode life cycle and maintain capacity. Conventional synthetic techniques face serious problems in producing complex nanomaterials with precise design, high efficiency, and long life. Recent efforts have been made to utilize bio-inspired materials in a variety of applications, emphasizing the importance of biomimetics due to their unique advantages and excellent properties. This review examines the synthesis mechanism, properties, and advances of bioinspired materials in the production of nanomaterials in order to pave the way for the future study of rechargeable batteries. Subsequently, the solutions and problems encountered by cathode materials in the main categories of secondary rechargeable batteries are addressed. The aim of this study is to alert scientists toward this promising development trend in bio-inspired battery materials.

Coupling of 3D Porous Hosts for Li Metal Battery Anodes with Viscous Polymer Electrolytes

As the energy storage markets demand increased capacity of rechargeable batteries, Li metal anodes have regained major attention due to their high theoretical specific capacity. However, Li anodes tend to have dendritic growth and constant electrolyte consumption upon cycling, which lead to safety concerns, low Coulombic efficiency, and short cycle life of the battery. In this work, both conductive and non-conductive 3D porous hosts were coupled with a viscous (melt) polymer electrolyte. The cross-section of the hosts showed good contact between porous hosts and the melt polymer electrolyte before and after extensive cycling, indicating that the viscous electrolyte successfully refilled the space upon Li stripping. Upon deep Li deposition/stripping cycling (5 mAh cm-2), the non-conductive host with the viscous electrolyte successfully cycled, while conductive host allowed rapid short circuiting. Post-mortem cross-sectional imaging showed that the Li deposition was confined to the top layers of the host. COMSOL simulations indicated that current density was higher and more restricted to the top of the conductive host with the polymer electrolyte than the liquid electrolyte. This resulted in quicker short circuiting of the polymer electrolyte cell during deep cycling. Thus, the non-conductive 3D host is preferred for coupling with the melt polymer electrolyte.

Lithium-Ion-Conducting Ceramics-Coated Separator for Stable Operation of Lithium Metal-Based Rechargeable Batteries

Lithium metal anode is regarded as the ultimate negative electrode material due to its high theoretical capacity and low electrochemical potential. However, the significantly high reactivity of Li metal limits the practical application of Li metal batteries. To improve the stability of the interface between Li metal and an electrolyte, a facile and scalable blade coating method was used to cover the commercial polyethylene membrane separator with an inorganic/organic composite solid electrolyte layer containing lithium-ion-conducting ceramic fillers. The coated separator suppressed the interfacial resistance between the Li metal and the electrolyte and consequently prolonged the cycling stability of deposition/dissolution processes in Li/Li symmetric cells. Furthermore, the effect of the coating layer on the discharge/charge cycling performance of lithium-oxygen batteries was investigated.

Overview of the Recent Progress of Suppressing the Dendritic Growth on Lithium Metal Anode for Rechargeable Batteries

The lithium metal has been considered as a competitive material for anode on the high-energy storage battery because of its various advantages, such as high capacity, low density, and the lowest electrochemical potential. However, the uncontrolled dendritic growth on the anode surface could cause the short circuit, even explosion of the battery. Therefore, strategies about how to effectively inhibit the formation of dendrites is of great importance. This paper will first give a brief introduction on the growth of dendrites. The attention is then focused on the recent advancements to suppress the dendrite growth of lithium metal, such as the optimization of electrolyte, application of artificial solid electrolyte interphase (SEI), and the modification of lithium anode. The future research directions will be presented at the end.