Challenges for Safe Electrolytes Applied in Lithium-Ion Cells-A Review

The aspect of safety in electronic devices has turned out to be a huge challenge for the world of science. Thus far, satisfactory power and energy densities, efficiency, and cell capacities have been achieved. Unfortunately, the explosiveness and thermal runaway of the cells prevents them from being used in demanding applications such as electric cars at higher temperatures. The main aim of this review is to highlight different electrolytes used in lithium-ion cells as well as the flammability aspect. In the paper, the authors present liquid inorganic electrolytes, composite polymer-ceramic electrolytes, ionic liquids (IL), polymeric ionic liquids, polymer electrolytes (solvent-free polymer electrolytes (SPEs), gel polymer electrolytes (GPEs), and composite polymer electrolytes (CPEs)), and different flame retardants used to prevent the thermal runaway and combustion of lithium-ion batteries (LIBs). Additionally, various flame tests used for electrolytes in LIBs have been adopted. Aside from a detailed description of the electrolytes consumed in LIBs. Last section in this work discusses hydrogen as a source of fuel cell operation and its practical application as a global trend that supports green chemistry.

Modern Nanocomposites and Hybrids as Electrode Materials Used in Energy Carriers

Over the past decades, the application of new hybrid materials in energy storage systems has seen significant development. The efforts have been made to improve electrochemical performance, cyclic stability, and cell life. To achieve this, attempts have been made to modify existing electrode materials. This was achieved by using nano-scale materials. A reduction of size enabled an obtainment of changes of conductivity, efficient energy storage and/or conversion (better kinetics), emergence of superparamagnetism, and the enhancement of optical properties, resulting in better electrochemical performance. The design of hybrid heterostructures enabled taking full advantage of each component, synergistic effect, and interaction between components, resulting in better cycle stability and conductivity. Nowadays, nanocomposite has ended up one of the foremost prevalent materials with potential applications in batteries, flexible cells, fuel cells, photovoltaic cells, and photocatalysis. The main goal of this review is to highlight a new progress of different hybrid materials, nanocomposites (also polymeric) used in lithium-ion (LIBs) and sodium-ion (NIBs) cells, solar cells, supercapacitors, and fuel cells and their electrochemical performance.

Kinetics and Thermodynamics of Thermal Degradation of Different Starches and Estimation the OH Group and H2O Content on the Surface by TG/DTG-DTA

The main aim of this study is to estimate the kinetic and thermodynamic parameters of thermal decomposition of starches by the Coats-Redfern method. This procedure is a commonly used thermogravimetric analysis/difference thermal gravimetry/differental thermal analysis (TG/DTG-DTA) kinetic method for single rate form. The study also shows a proposed method for reactive hydroxyl groups content on the starch surface determination, and values were in range of 960.21-1078.76 mg OH per 1 g of starch. Thermal processing revealed the thermophysical properties of biomass for the kinetics of decomposition estimation. Activation energies reached the values in range of approximately 66.5-167 kJ·mol-1. This research also enables the determination of the temperature conditions required for becoming the desired form of material. Therefore, it is necessary to achieve the requested compact porous structure in an activation process, because in the native state, the polymer exhibits limited applications as a result of thermal decomposition, low shear stress, retrogradation, and syneresis, hence the low solubility in organic solvents. Thermodynamic parameters and reactive hydroxyl groups in this article review are innovative and have not yet been found in the literature.