Pomegranate-inspired Zn2Ti3O8/TiO2@C nanospheres with pseudocapacitive effect for ultra-stable lithium-ion batteries

As a new-type anode material for lithium-ion batteries, Zn2Ti3O8 has attracted enormous attention because of the low cost, excellent safety, and high theoretical capacity of 466 mAh g-1. However, the practical capacity and cycling stability are always suppressed by poor intrinsic conductivity, sluggish reaction kinetics, and serious volume change during electrochemical reaction. To tackle the aforementioned issues, a facile and scalable strategy is developed to prepare pomegranate-inspired nanospheres, in which ultrafine Zn2Ti3O8/TiO2 nanoparticles are embedded in a hierarchical carbon framework (Zn2Ti3O8/TiO2@C). The nanoscale spherical structure constructed by ultrafine nanoparticles enables to reduce Li+ diffusion distance, relieve volume expansion, and induce additional pseudocapacitive effect. The favorable dispersion of ultrafine Zn2Ti3O8/TiO2 nanoparticles in the conductive carbon framework prevents the agglomeration of the active nanoparticles, guaranteeing a rapid electron transfer path. Benefiting from these unique structural properties, the as-prepared Zn2Ti3O8/TiO2@C electrode exhibits a high capacity of 380 mAh g-1 at 100 mA g-1 and remarkable cycling life up to 1800 cycles even at 1000 mA g-1. Therefore, this work will provide beneficial enlightenment for novel material structure design and accelerate the application of Zn2Ti3O8 in lithium-ion batteries.

Automated summary

A novel strategy was developed to prepare pomegranate-inspired nanospheres in which ultrafine Zn2Ti3O8/TiO2 nanoparticles are embedded in a hierarchical carbon framework (Zn2Ti3O8/TiO2@C). This structure effectively reduces Li+ diffusion distance, relieves volume expansion, and induces additional pseudocapacitive effect, leading to a high capacity and remarkable cycling life of the Zn2Ti3O8/TiO2@C electrode. This work provides beneficial enlightenment for novel material structure design and accelerates the application of Zn2Ti3O8 in lithium-ion batteries.