Acta Chimica Sinica ›› 2022, Vol. 80 ›› Issue (9): 1264-1268.DOI: 10.6023/A22040144 Previous Articles     Next Articles



梁世硕a,b, 康树森b,*(), 杨东a, 胡建华a   

  1. a 聚合物分子工程国家重点实验室 复旦大学高分子科学系 上海 200438
    b 欣旺达电动汽车电池有限公司 深圳 518107
  • 投稿日期:2022-04-01 发布日期:2022-05-22
  • 通讯作者: 康树森
  • 基金资助:
    国家自然科学基金(51773042); 国家自然科学基金(51973040)

Interficial Engineering of Lithium Metal Anode for Sulfide Solid State Batteries

Shishuo Lianga,b, Shusen Kangb(), Dong Yanga, Jianhua Hua   

  1. a State Key Laboratory of Molecular Engineering of Polymers and Department of Macromolecular Science, Fudan University, Shanghai 200438, China
    b Sunwoda Electric Vehicle Battery Company, Shenzhen 518107, China
  • Received:2022-04-01 Published:2022-05-22
  • Contact: Shusen Kang
  • Supported by:
    National Natural Science Foundation of China(51773042); National Natural Science Foundation of China(51973040)

Lithium metal anode is recognized as the “Holy Grail” electrode because of its high specific capacity (3860 mAh/g) and low reduction potential (–3.04 V vs. standard hydrogen electrode), which is meaningful for batteries systems. Remarkable improvement of ionic conductivity of sulfide electrolyte exceeding 10 mS/cm at room temperature has opened up the opportunity to realized the commercialization of lithium metal anode. However, the practical implement of Li anode in solid-state batteries is hundered by the poor cycle stability and the low energy efficiency stemming from the unstable interfaces due to the ultrahigh reactivity of lithium metal. At the anode interface, the lithium dendrite growth and solid electrolytes (SE) reduction by lithium metal are serious challenges for lithium metal anode. To suppress the interfacial reactions and lithium dendrite formation at the sulfide electrolyte/Li metal anode interface, various strategies have been implemented by researchers, such as in situ formed robust SEI (solid electrolyte interface), surface modification and SE modification, etc. In this article, we focus on the artificial solid electrolyte interface (ASEI) to strengthening the Li metal and solid electrolyte interface. We fabricate the uniform LiF-rich ASEI using CF3(CF2)3OCH3 by heating at a temperature of 150 ℃ for 6 h. LiF layer at the interface between Li and sulfide electroyte could prevent Li dendrite growth. Compared to the Li/sulfide electrolyte interface, the Li/LiF/sulfide electrolyte interface is more stable. The symmetrical cell LiF@Li//Li6PS5Cl//LiF@Li (LiF@Li//LPSCl//LiF@Li) does not short-circuit after 40 cycles at the current density of 0.1 mAh/cm2 with a lower polarization potential. A solid-state battery LiNbO2@LiCoO2//LPSCl//LiF@Li (LNO@LCO//LPSCl//LiF@Li) employing LiF coated Li metal as anode shows a high reversible discharge capacity of 138.4 mAh/g at 0.05 C and retains 110.9 mAh/g after 50 cycles. This interficial engineering for lithium metal and sulfide solid electrolyte provides new opportunity to commercialize the Li metal batteries.

Key words: interfacial engineering, sulfide solid electrolyte, LiF artificial solid electrolyte interface, lithium metal anode, solid-state battery