Acta Chimica Sinica ›› 2020, Vol. 78 ›› Issue (12): 1434-1440.DOI: 10.6023/A20070290 Previous Articles     Next Articles



于越a,b, 张新波a,b   

  1. a 中国科学院长春应用化学研究所 稀土资源利用国家重点实验室 长春 130022;
    b 中国科学技术大学 合肥 230026
  • 投稿日期:2020-07-18 发布日期:2020-10-15
  • 通讯作者: 张新波
  • 基金资助:

Porous Metal-Organic Frameworks Lithium Metal Anode Protection Layer towards Long Life Li-O2 Batteries

Yu Yuea,b, Zhang Xinboa,b   

  1. a State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China;
    b University of Science and Technology of China, Hefei 230026, China
  • Received:2020-07-18 Published:2020-10-15
  • Supported by:
    Project supported by the National Key R&D Program of China (No. 2016YFB0100103), the Technology and Industry for National Defence of the People’s Republic of China (No. JCKY2016130B010), and the National Natural Science Foundation of China (Nos. 21725103, 21771013).

Among the numerous successors of Li-ion batteries, Li-O2 cells become promising candidates because of their higher theoretical energy density (3500 Wh·kg-1). However, the uncontrolled dendrite growth and serious corrosion issues of lithium metal anode are major bottlenecks for practical application of Li-O2 batteries. To solve the above challenges, herein, we prepared metal-organic frameworks materials (MOF-801) with high specific surface area and abundant pores as a protection layer on lithium metal anode in Li-O2 batteries. In this manuscript, pure and cubic-shaped MOF-801 materials are successfully synthesized and the high specific surface area (762.9 m2·g-1) is confirmed. And MOF-801 is verified stable enough as a protection layer towards lithium metal anode and tetraethylene glycol dimethyl ether (TEGDME) 1 mol·L-1 LiCF3SO3 electrolyte system. Due to the rich pore structures and high specific surface area, MOF-801 can assist to form uniform Li+ flux and dendrite-free lithium deposition morphology can be confirmed in the scanning electron microscope images, which can avoid the short circuit even fire disaster from the uncontrollable dendrite growth. Besides, the shield effect as well as the water capture function of MOF-801 protection layer can also effectively prevent serious side reactions from the shuttle effect of the contaminants (H2O, O2 and strong oxidizing species). Consequently, this strategy enables stable electrode/electrolyte interface and achieves 800 h plating/stripping cycles under a low overpotential of 0.023 V. In contrast, the batteries without protection can only run for 254 h with the overpotential as high as 5 V at last. The electrochemical impedance spectroscopy results also verify that the much lower impedance of the lithium metal anode after protection. When applied in practical Li-O2 batteries with a fixed capacity of 1000 mAh·g-1 at a current density of 500 mA·g-1, stable and long-life cycle performance (170 cycles) has been realized in the Li-O2 batteries with MOF-801 protection layer, which is 2.88 times longer than those without protection. The batteries with MOF-801 protection layer also deliver a high discharge specific capacity of 8935 mAh·g-1. This unique protection layer design strategy illustrates fresh insight towards protection strategy in alkali metal anode batteries.

Key words: Li-O2 battery, lithium metal anode, metal-organic frameworks, dendrite suppression, lithium corrosion