Acta Chim. Sinica ›› 2015, Vol. 73 ›› Issue (8): 808-814.DOI: 10.6023/A15030151 Previous Articles     Next Articles

Article

高容量金属镓薄膜和粉体作为锂离子电池负极材料的自修复行为研究

罗飞a, 郑杰允a, 褚赓a, 刘柏男a, 张素林b, 李泓a, 陈立泉a   

  1. a 中国科学院物理研究所 北京 100190;
    b The Pennsylvania State University, PA 16802, USA
  • 收稿日期:2015-03-03 出版日期:2015-08-14 发布日期:2015-06-02
  • 通讯作者: 李泓, 张素林 E-mail:hli@iphy.ac.cn;suz10@psu.edu
  • 基金资助:

    项目受中国科学院战略性先导科技专项(No. XDA09010102)、国家杰出青年基金(No. 51325206)和973计划(No. 2012CB932900)资助.

Self-healing Behavior of High Capacity Metal Gallium Thin Film and Powder as Anode Material for Li-ion Battery

Luo Feia, Zheng Jieyuna, Chu Genga, Liu Bonana, Zhang Sulinb, Li Honga, Chen Liquana   

  1. a Institute of Physics, Chinese Academy of Science, Beijing 100190;
    b The Pennsylvania State University, PA 16802 USA
  • Received:2015-03-03 Online:2015-08-14 Published:2015-06-02
  • Supported by:

    Project supported by “Strategic Priority Research Program” of the Chinese Academy of Sciences (No. XDA09010102), The National Science Fund for Distinguished Young Scholars (No. 51325206) and 973 project of MOST (No. 2012CB932900).

Alloy anode materials, such as Si, Sn, have attracted much attention due to their much higher theoretical capacities than that of the commercially used graphite electrodes. However, their commercial applications are limited because of the short cycle life due to the large volume changes and non-healable fracture during electrochemical cycling. In this work, we prepared metal Ga thin film electrodes on stainless steel substrate (diameter 1.4 cm, mass load 1.5~2 mg/cm2) to study the self-healing behavior of Ga anodes. After 25 cycles, the cells were disassembled in Ar-filled glove box and the metal Ga thin film electrodes were washed by dimethyl carbonate (DMC) to remove residual LiPF6 and then dried in the vacuum chamber for more than 2 hours before SEM analysis. Based on SEM observation and crack size statistical distribution, we found that the characteristic size of the self-healing area reduced to 34 μm after 25 cycles and gradually reduced with the increasing cycles using low-melting point metal Ga film electrodes at a temperature above the melting point of Ga. Energy dispersive spectrometer (EDS) analysis showed that there was a large amount of F, O and C at the surface of metal Ga thin film electrodes, which are considered as main components of the solid electrolyte interface (SEI) layer. The formation of the SEI layer degrades the self-healing capability of Ga metal thin films because the layer may attach on the crack surfaces after full delithiation, hindering self-healing of the Ga films. Metal Ga powder electrodes (mass load 4.3 mg/cm2) were prepared by simple liquid dispersion method. The size of the Ga metal powder was 3.43 μm, which is smaller than that of effective self-healing area. Electrochemical performance showed improved durability of the metal Ga powder electrodes compared to the metal Ga thin film electrodes. After 25 cycles, the average crack size of the metal Ga powder electrodes was 1 μm based on SEM images. This shows that the self-healing ability of metal Ga in liquid electrolyte is limited. Metal Ga is expected to be used as crack healing agent in non-liquid electrolyte systems, such as the solid-state batteries.

Key words: metal gallium, anode material, Li-ion battery, self-healing