sodium-ion batteries

Sodium trititanate, Na2Ti3O7, is considered to be a promising material for the negative electrode of reliable sodium-ion batteries. The advantages of Na2Ti3O7 include suitable electrode potential and cycling stability. However, this material is characterized by the limited specific capacity and low electronic conductivity. The current work is devoted to modification of Na2Ti3O7 by combining it with the high-capacity α-Fe2O3 phase.

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.

The critical analysis of literature of last 15 years, concerning solid polymer electrolytes with Na⁺-ion-conductivity is presented. True polymer electrolytes as well as gel-polymer electrolytes based on polyethylene oxide, polyacrylonitrile, polyvinyl alcohol, polyvinyl chloride, polyvinyl pyrrolidone, PVdF–HFP, PMMA, Nafion are reviewed. Special attention is paid for temperature dependence of conductivity.