Layer-structured NbSe2 anode material for sodium-ion and potassium-ion batteries

Abstract

Layered compounds with large interlayer spacing enabling ions intercalation are promising anode materials for sodium-ion and potassium-ion batteries. Herein, we prepared the high-purity layer-structured NbSe2 sheets with compatible interlayer spacing (6.30 A) via a facile solid-state vacuum sintering. The as-prepared NbSe2 was explored as anode materials for sodium and potassium batteries for the first time. The NbSe2 exhibits excellent cycle stability and rate performance for sodium storage, which provides initial reversible capacity of 116.6 mA h g−1 and retention capacity of 98.1 mA h g−1 after 100 cycles at 100 mA g−1. A capacity of 78.6 mA h g−1 was achieved even at a high current density of 4000 mA g−1. The sodium-ion storage mechanism of NbSe2 was primitively discussed in this paper. NbSe2 also demonstrates considerable potassium storage capacity and good rate performance. The results indicate that NbSe2 may be a promising anode for sodium-ion and potassium-ion batteries as a novel anode material.