lithium-ion batteries

The use of solid polymer electrolytes is a novel and promising approach for enhancing the safety of lithium-ion and sodium-ion batteries. A number of publications on manufacturing electrolytes with lithium-ion and sodium-ion conductivity based on Nafion-like polymers have appeared in recent decade. The present mini-review analyses various methods of the synthesis of such electrolytes and their properties, as well as the information on laboratory lithium-ion and sodium-ion batteries using such electrolytes.

A brief analysis of the current situation in the development of lithium-ion batteries in Russia and all over the world has been carried out. The conclusion is made that Russia produces only a basis point of lithium-ion batteries in the world. It is predicted that Russian production of lithium-ion batteries may increase up to 0.2% in the world by 2030.

The flash point tester PE-TVZ was modernized. The sample volume was reduced from 70 to 5 ml. Mixing of the condensed and gas-vapor phases was done simultaneously. The mercury thermometer was replaced by an electronic one. The correctness of the flash point measurement by the modernized device was tested on the samples with the flash point in the range of 25–170°C.

The reversible insertion of lithium into electrodes based on amorphous boron has been studied. The reversible capacity upon the lithium insertion has been found to be about 750 mA⋅h/g. The most efficient in terms of specific capacity are the electrodes containing graphene as a conductive additive.

On basis of analysis of literature data as well as of own experimental results we suggest some regularity for degradation of silicon electrodes upon cycling. It was shown that an electrode capacity Q at n-th cycle can be calculated from equation Q = Q₀ exp(kn+?n²/2), where Q₀ is initial capacity value, k и ? are empiric constants.

DOI: https://doi.org/10.18500/1608-4039-2017-17-2-61-88

The critical analysis of literature of last 15 years, concerning features of low-temperature behavior of lithium-ion batteries is presented. Some generalized approaches to the problem as well as the role of main polarization components at low temperatures; features of functioning of negative and positive electrodes are reviewed. Some low-temperature electrolytes are reviewed as well.

DOI: https://doi.org/10.18500/1608-4039-2017-17-1-19-28

The review of cathode materials for lithium-ion batteries is presented, the analysis of advantages and application prospects of cathode materials on the basis of lithiated transition metals oxides is carried out. A method of heterovalent modification by ions of highly negative elements, lanthanum and its analogues for improving the electrochemical indices and stability of lithium manganese spinel is proposed. The effectiveness of fullerene, lithium fluoride, fullerenes halogen derivatives as modifying additive for MnO₂ cathode materials has been noticed.

The current situation in technology and developments in the field of polymer binders for composite electrodes of lithium electrochemical systems are discussed. A wide range of synthetic and natural polymers used for this purpose is considered. Emphasis is placed on commercially available materials, which form aqueous solutions or dispersions. The advantages of multifunctional polymer binders are demonstrated.

The second part of the review describes the prospects of using alternative polymer binders for composite electrodes of lithium electrochemical systems. Possible options having been taken into account, the most popular commercially-available synthetic polymers with functional group (the ones forming aqueous solutions or dispersions predominantly) and water-soluble polymers of natural origin are considered. The versatility of such materials is their distinctive feature.