Two-dimensional self-assembled TiSe2 micro-nanoparticles toward high-performance sodium ions storage

Abstract

Sodium-ion batteries (SIBs) are potential commercial energy storage devices. However, the inadequate long-term cycling stability and rate capability of anode materials continue to hinder the commercial application of SIBs. TiSe2 is regarded as a potential anode for SIBs owing to its high electrical conductivity and unique layered structure. Herein, a novel TiSe2 anode for sodium storage at extraordinary current has been prepared through a simple one-step solid-phase selenization method. The layered microstructure constituted of nanoparticles can not only ensure rapid ion/electron transport, but also effectively suppress the structure collapse over repeated cycles. Benefiting from the design advantages, the layered TiSe2 equips features of good structural stability, high pseudocapacitive behavior, and low impedance, thereby retaining a capacity of 76.7 mAh g−1 at an ultra-high current density of 40 A g−1 and a capacity of 155.6 mAh g−1 even after 3,000 cycles at 10 A g−1. Moreover, in situ and ex situ technologies clearly reveal the reversible reaction mechanism, also ensuring favourable electrochemical performance,