Direct synthesis of carbon-coated Li4Ti5O12 mesoporous nanoparticles for high-rate lithium-ion batteries

作者：Guan, Xiangfeng^*; Chen, Xiaomei; Li, Guangshe; Zang, Yipeng; Lin, Haifeng; Luo, Dong; Li, Liping

来源：RSC Advances, 2013, 3(9): 3088-3094.

DOI：10.1039/c2ra21321d

• ONE-STEP SYNTHESIS
• ANODE MATERIAL
• ELECTROCHEMICAL PERFORMANCE
• ELECTRODE
• ROUTE

The carbon-coated Li4Ti5O12 mesoporous nanoparticles were directly synthesized by a facile solvothermal method with a subsequent N-2 treatment. The resultant Li4Ti5O12 did not show any by-products of TiN or TiC, but a unique mesoporous structure and particle dimension of about 20 nm. Confined to the surface thin layer <5 nm of this mesoporous structure was carbon species, which amounts to 0.98 wt%, much less than that when using conventional carbon-coating method. Systematic electrochemical tests on these mesoporous nanoparticles demonstrated an excellent cycling performance with Coulombic efficiencies being all higher than 99% after the initial cycle. Further, when cycled at a high rate of 10 C, these mesoporous nanoparticles delivered an initial discharge capacity of 137 mAh g(-1) and maintained a high reversible capacity of 107 mAh g(-1) after 1600 cycles, which is apparently much higher than that of 67 mAh g(-1) for the first discharge capacity of non-mesoporous Li4Ti5O12. The improved electrochemical performances of Li4Ti5O12 can be attributed to the mesoporous structure and thin carbon coating on Li4Ti5O12 nanoparticles, which facilitates electron and lithium-ion diffusion.

• 出版日期2013
• 单位中国科学院福建物质结构研究所