Ni0.05Ti1.95Nb10O29: an advanced anode material for high-performance lithium-ion storage

Abstract

Ti₂Nb₁₀O₂₉ (TNO) has garnered significant research attention due to its high specific capacity and excellent safety features, positioning it as a promising anode material for lithium-ion batteries (LIBs). Nevertheless, its rate capability is significantly hampered by poor electronic and ionic conductivity. In this paper, Ni²⁺ doping has been first applied to address these issues. A series of Ni²⁺ doped TNO (Ni_x-TNO (x = 0.03, 0.05, 0.07) electrode materials have been prepared to unveil the effects of Ni²⁺ content. The experimental results unveil that Ni²⁺ doping maintains the Wadsley-Roth shear structure of TNO while augmenting the single-cell volume and introducing additional oxygen vacancies in TNO. This generates a wider diffusion path and more active sites for lithium ions (Li⁺). Besides, the introduction of Ni²⁺ can alter the conductive field distribution of TNO, giving rise to a much higher electronic conductivity of Ni_x-TNO. Among the synthesized Ni_x-TNO, Ni_0.05-TNO shows the best electrochemical performance, demonstrating a reversible capacity of 306 mAh g^–1 with a Coulombic efficiency of 91.46% in the first cycle at 0.1 C and 146.19 mAh g^–1 at 10 C after 500 cycles.