Nonporous TiO2@C microsphere with a highly integrated structure for high volumetric lithium storage and enhance initial coulombic efficiency

Abstract

Abstract To enhance the volumetric energy density and initial coulombic efficiency (ICE) of titanium oxide (TiO2) as anode electrode material for lithium-ion batteries (LIB), this study employed a surface-confined in-situ inter-growth mechanism to prepare a TiO2 embedded carbon microsphere composite. The results revealed that the composite exhibited a highly integrated structure of TiO2 with oxygen vacancies and carbon, along with an exceptionally small specific surface area of 11.52 m2/g. Due to its unique microstructure, the composite demonstrated remarkable lithium storage properties, including a high ICE of 75%, a notable capacity of 426.8 mAh/g after 200 cycles at 0.2 A/g, superior rate performance of 210.1 mAh/g at 5 A/g, and an outstanding cycle life, with a capacity decay rate of only 0.003% per cycle over 2000 cycles. Furthermore, electrochemical kinetic studies further validated the advantages of this microstructure.

Keywords

• Lithium-ion batteries
• TiO2
• Coulombic efficiency
• Oxygen vacancies