中文摘要：

提出利用氦渗透法优化LiFePO4材料的结晶生长过程,达到提高材料电化学性能的目的。采用磁控溅射法制备含氦LiFePO4薄膜电极,利用扫描电镜观察样品的微观形貌,发现样品表面与截面皆呈现多孔结构。用X射线衍射仪分析含氦LiFePO4薄膜电极的晶体结构。结果表明,氦渗入薄膜后显著增强了材料在29.81°的衍射峰强度,而此处正对应了锂离子在LiFePO4材料中的扩散路径（[010]方向）。这表明含氦LiFePO4薄膜中存在有利于材料脱锂/嵌锂的结晶择优生长取向,会导致薄膜电极电化学性能的提高。

英文摘要：

The changes of the crystal orientation and lattice defects have a considerable impact on the electrochemical performances of lithium ion electrodes.Here,a new method of controlling the crystal growth of the LiFePO4 films by helium permeation was developed.The helium-permeated LiFePO4 thin film cathodes were prepared by radio frequency（RF） magnetron sputtering deposition.The morphologies of the helium-permeated LiFePO4 samples characterized by scanning electron microscope（SEM）presented pore structure.The X-ray diffraction（XRD） results of the LiFePO4 thin film cathodes indicate that the permeation of helium results in a noticeable increase of peak intensity at the 29.81°,which is normal to the pathway for lithium ion conduction（the[010]direction）.It is concluded that there exists a preferential crystal growth orientation of（010） face which is in favor for the reversible insertion/de-insertion of Li ions,and therefore leading to the improvement in electrochemical performance of LiFePO4samples.