Scalable synthesis of graphene-wrapped Li4Ti5O12 dandelion-like microspheres for lithium-ion batteries with excellent rate capability and long-cycle life

Abstract

A three-dimensional dandelion-like Li₄Ti₅O₁₂@graphene microsphere electrode is designed by using a simple and scalable solution fabrication process. The graphene nanosheets are incorporated into the porous dandelion-like Li₄Ti₅O₁₂ microspheres homogenously, which provide a highly conductive network for electron transportation. When tested as an anode for Li-ion batteries, the dandelion-like Li₄Ti₅O₁₂@graphene composite with 3 wt% graphene exhibits excellent rate capabilities and superior cycle life between 0.01 and 3.0 V. The capacities of Li₄Ti₅O₁₂@graphene (3 wt%) reach 206 mA h g⁻¹ after 500 cycles between 0.01 and 3.0 V and 166 mA h g⁻¹ after 100 cycles between 0.7 and 3.0 V at a current density of 0.12 A g⁻¹, respectively. In addition, Li₄Ti₅O₁₂-based anode materials at lower voltage can offer a higher cell voltage and discharge capacity for lithium-ion batteries. Hence, it is significant to study the electrochemical behaviors of the Li₄Ti₅O₁₂-based anode in a wide voltage range of 0.01–3.0 V. This facile and scalable method for Li₄Ti₅O₁₂@graphene composites represents an effective strategy to develop advanced electrochemical energy storage systems with long cycle life and high rate performance.