Kim Jae-Geun, Park Min-Sik, Hwang Soo Min, Heo Yoon-Uk, Liao Ting, Sun Ziqi, Park Jong Hwan, Kim Ki Jae, Jeong Goojin, Kim Young-Jun, Kim Jung Ho, Dou Shi Xue
Institute for Superconducting and Electronic Materials, University of Wollongong, Innovation Campus, North Wollongong, NSW 2500 (Australia).
ChemSusChem. 2014 May;7(5):1451-7. doi: 10.1002/cssc.201301393. Epub 2014 Apr 2.
One-dimensional nanomaterials have short Li(+) diffusion paths and promising structural stability, which results in a long cycle life during Li(+) insertion and extraction processes in lithium rechargeable batteries. In this study, we fabricated one-dimensional spinel Li4Ti5O12 (LTO) nanofibers using an electrospinning technique and studied the Zr(4+) doping effect on the lattice, electronic structure, and resultant electrochemical properties of Li-ion batteries (LIBs). Accommodating a small fraction of Zr(4+) ions in the Ti(4+) sites of the LTO structure gave rise to enhanced LIB performance, which was due to structural distortion through an increase in the average lattice constant and thereby enlarged Li(+) diffusion paths rather than changes to the electronic structure. Insulating ZrO2 nanoparticles present between the LTO grains due to the low Zr(4+) solubility had a negative effect on the Li(+) extraction capacity, however. These results could provide key design elements for LTO anodes based on atomic level insights that can pave the way to an optimal protocol to achieve particular functionalities.
一维纳米材料具有较短的锂离子扩散路径和良好的结构稳定性，这使得其在锂可充电电池的锂嵌入和脱出过程中具有较长的循环寿命。在本研究中，我们采用静电纺丝技术制备了一维尖晶石Li4Ti5O12（LTO）纳米纤维，并研究了Zr(4+)掺杂对锂离子电池（LIBs）的晶格、电子结构以及由此产生的电化学性能的影响。在LTO结构的Ti(4+)位点中容纳少量的Zr(4+)离子可提高LIB的性能，这是由于平均晶格常数增加导致结构畸变，从而扩大了锂离子扩散路径，而非电子结构发生变化。然而，由于Zr(4+)溶解度低，LTO晶粒之间存在绝缘的ZrO2纳米颗粒，这对锂离子脱出容量有负面影响。这些结果基于原子水平的见解可为LTO负极提供关键设计要素，从而为实现特定功能的最佳方案铺平道路。
