Carbon-coated Li₄Ti₅O₁₂–TiO₂ microspheres as anode materials for lithium ion batteries

ABSTRACT

While spinel Li₄Ti₅O₁₂ has attracted great attention owing to its excellent cycling stability and safety as anode materials of lithium ion batteries, there is still a challenge to produce high-performance Li₄Ti₅O₁₂ with a cost-effective and scalable process. Herein, we developed a facile one-pot strategy for scalable synthesis of carbon-coated Li₄Ti₅O₁₂–TiO₂ microspheres. The novel material not only delivered a high capacity of 162.5 mA h g⁻¹ after 100 cycles at 0.5 C but also exhibited excellent rate capability and cycling stability. The capacity of up to 146.6 mA h g⁻¹ was retained after 350 cycles at 5 C, and no obvious capacity reduction was found during cycles. The superior electrochemical performance can be attributed primarily to the uniform carbon layer outside and the high density of grain boundary in the compact microspheres, resulting in enhanced electrical conductivity and more channels for lithium ion insertion/extraction reaction.

KEYWORDS:

• Li₄Ti₅O₁₂
• anode
• carbon coating
• grain boundary

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The authors thank the financial supports by National Natural Science Foundation of China (#11472080), the Natural Science Foundation of Jiangsu Province of China (#BK20141336), the Fundamental Research Funds for the Central Universities (#3212006401) and Jiangsu Key Laboratory for Advanced Metallic Materials (#BM2007204) and State Key Laboratory for Mechanical Behavior of Materials (#20141603).