Energy storage is an extremely important problem today. Among the most efficient batteries, lithiumion occupy a special place. Lithium is the most active known reducing agent. It has a huge energy storage resource. 1 kg of lithium is capable of storing 3860 ampere-hours. However, lithium-ion batteries have almost reached their limits and are characterized by a high cost, which raises the question of the further development of such technologies based on the so-called post-lithium-ion batteries. This paper provides an overview of post-lithium-ion batteries such as lithium-oxygen batteries, sodium-ion batteries, lithiumsulfur batteries and their comparison with known lithium-ion batteries. The commercialization of postlithium-ion batteries is also discussed.
The performance of sodium-ion batteries largely depends on the presence and properties of passive films formed on the electrode/electrolyte interfaces. Passive films on negative electrodes inevitably result from the reduction in electrolyte components (solvent and salt anion). They have the properties of a solid electrolyte with sodium ion conductivity and are insulators in terms of electronic conductivity. Usually, they are called SEI—solid electrolyte interphase. The formation of SEI is associated with the consumption of a certain charge, which is an irreversible capacity. Passive films on the surface of positive electrodes (CEI—cathode electrolyte interphase) arise as a result of electrolyte oxidation. The present review summarizes the literature of the recent 15 years concerning the effects of electrode nature (hard carbon, other carbon materials, various metals, oxides, chalcogenides, etc.), electrolyte composition, and other factors on composition and properties of SEIs in sodium-ion batteries. Literary data on CEIs are reviewed as well, although their volume is inferior to that of data on SEIs.
Nanostructure composites Ge-Co-P with brutto-composition CoGe2P0.1, or CoGe2@GeP were manufactured via electrolysis of aqueous electrolyte. Such composites are able to reversible insertion of lithium and sodium with specific capacities up to 855 and 425 mAh/g, respectively. The main advantage of the composites consists in their excellent cycleability.