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

摘要

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.