High Performance Li4Ti5O12/Si Composite Anodes for Li-Ion Batteries

Nanomaterials

Chunhui Chen¹  Richa Agrawal¹  Chunlei Wang² 

[1] Department of Mechanical and Materials Engineering, Florida International University, Miami, FL 33174, USA;

关键词: lithium titanate;    silicon;    rate capability;    energy capacity;    composite;   

DOI  :  10.3390/nano5031469

来源: mdpi

【 摘 要 】

Improving the energy capacity of spinel Li₄Ti₅O₁₂ (LTO) is very important to utilize it as a high-performance Li-ion battery (LIB) electrode. In this work, LTO/Si composites with different weight ratios were prepared and tested as anodes. The anodic and cathodic peaks from both LTO and silicon were apparent in the composites, indicating that each component was active upon Li⁺ insertion and extraction. The composites with higher Si contents (LTO:Si = 35:35) exhibited superior specific capacity (1004 mAh·g⁻¹) at lower current densities (0.22 A·g⁻¹) but the capacity deteriorated at higher current densities. On the other hand, the electrodes with moderate Si contents (LTO:Si = 50:20) were able to deliver stable capacity (100 mAh·g⁻¹) with good cycling performance, even at a very high current density of 7 A·g⁻¹. The improvement in specific capacity and rate performance was a direct result of the synergy between LTO and Si; the former can alleviate the stresses from volumetric changes in Si upon cycling, while Si can add to the capacity of the composite. Therefore, it has been demonstrated that the addition of Si and concentration optimization is an easy yet an effective way to produce high performance LTO-based electrodes for lithium-ion batteries.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.