Hydrogen plasma reduced potassium titanate as a high power and ultralong lifespan anode material for sodium-ion batteries

Abstract

The abundance and low cost of sodium potentially enable application of sodium ion batteries for grid-scale energy storage. Consequently, anode materials with high power, long lifespan, and safe operation are highly desired. In this work, we successfully fabricate black K₂Ti₆O₁₃ nanowires as an anode material that exhibits the desired properties. The black K₂Ti₆O₁₃ nanowires are prepared via a hydrothermal method followed by post calcination and final hydrogen plasma treatment. The black K₂Ti₆O₁₃ anode delivers a high reversible capacity of 249 mA h g⁻¹. Impressively, it could sustain 20 000 cycles without apparent capacity fade. The first-principles calculation results suggest that the electrical conductivity of K₂Ti₆O₁₃ would be improved while the sodiation energy barrier could be reduced after introducing oxygen vacancies.