Applied Mathematics and Mechanics (English Edition) ›› 2020, Vol. 41 ›› Issue (4): 533-542.doi: https://doi.org/10.1007/s10483-020-2596-5

• 论文 •    下一篇

Atomic-scale simulations for lithium dendrite growth driven by strain gradient

Gao XU1, Feng HAO2, Jiawang HONG3, Daining FANG1,4   

  1. 1. State Key Laboratory for Turbulence and Complex Systems & Center for Applied Physics and Technology, College of Engineering, Peking University, Beijing 100871, China;
    2. Department of Engineering Mechanics, Shandong University, Jinan 250100, China;
    3. School of Aerospace Engineering, Beijing Institute of Technology, Beijing 100081, China;
    4. Institute of Advanced Structure Technology, Beijing Institute of Technology, Beijing 100081, China
  • 收稿日期:2020-01-06 修回日期:2020-01-20 出版日期:2020-04-01 发布日期:2020-03-26
  • 通讯作者: Jiawang HONG E-mail:hongjw@bit.edu.cn
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Nos. 11572040 and 11521202) and the National Key Research and Development Program of China (No. 2016YFB0700600)

Atomic-scale simulations for lithium dendrite growth driven by strain gradient

Gao XU1, Feng HAO2, Jiawang HONG3, Daining FANG1,4   

  1. 1. State Key Laboratory for Turbulence and Complex Systems & Center for Applied Physics and Technology, College of Engineering, Peking University, Beijing 100871, China;
    2. Department of Engineering Mechanics, Shandong University, Jinan 250100, China;
    3. School of Aerospace Engineering, Beijing Institute of Technology, Beijing 100081, China;
    4. Institute of Advanced Structure Technology, Beijing Institute of Technology, Beijing 100081, China
  • Received:2020-01-06 Revised:2020-01-20 Online:2020-04-01 Published:2020-03-26
  • Contact: Jiawang HONG E-mail:hongjw@bit.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Nos. 11572040 and 11521202) and the National Key Research and Development Program of China (No. 2016YFB0700600)

摘要: Dendrite formation is a major obstacle, e.g., capacity loss and short circuit, to the next-generation high-energy-density lithium (Li)-metal batteries. The development of successful Li dendrite mitigation strategies is impeded by an insufficient understanding in Li dendrite growth mechanisms. The Li-plating-induced internal stress in Li-metal and its effects on dendrite growth have been widely studied, but the underlying microcosmic mechanism is elusive. In the present study, the role of the plating-induced stress in dendrite formation is analyzed through first-principles calculations and ab initio molecular dynamic (AIMD) simulations. It is shown that the deposited Li forms a stable atomic nanofilm structure on the copper (Cu) substrate, and the adsorption energy of Li atoms increases from the Li-Cu interface to the deposited Li surface, leading to more aggregated Li atoms at the interface. Compared with the pristine Li-metal, the deposited Li in the early stage becomes compacted and suffers the in-plane compressive stress. Interestingly, there is a giant strain gradient distribution from the Li-Cu interface to the deposited Li surface, making the deposited atoms adjacent to the Cu surface tend to press upwards with perturbation and causing the dendrite growth. This provides an insight into the atomicscale origin of Li dendrite growth, and may be useful for suppressing the Li dendrite in Li-metal-based rechargeable batteries.

关键词: lithium (Li)-metal-based battery, Li dendrite, strain gradient, depositing

Abstract: Dendrite formation is a major obstacle, e.g., capacity loss and short circuit, to the next-generation high-energy-density lithium (Li)-metal batteries. The development of successful Li dendrite mitigation strategies is impeded by an insufficient understanding in Li dendrite growth mechanisms. The Li-plating-induced internal stress in Li-metal and its effects on dendrite growth have been widely studied, but the underlying microcosmic mechanism is elusive. In the present study, the role of the plating-induced stress in dendrite formation is analyzed through first-principles calculations and ab initio molecular dynamic (AIMD) simulations. It is shown that the deposited Li forms a stable atomic nanofilm structure on the copper (Cu) substrate, and the adsorption energy of Li atoms increases from the Li-Cu interface to the deposited Li surface, leading to more aggregated Li atoms at the interface. Compared with the pristine Li-metal, the deposited Li in the early stage becomes compacted and suffers the in-plane compressive stress. Interestingly, there is a giant strain gradient distribution from the Li-Cu interface to the deposited Li surface, making the deposited atoms adjacent to the Cu surface tend to press upwards with perturbation and causing the dendrite growth. This provides an insight into the atomicscale origin of Li dendrite growth, and may be useful for suppressing the Li dendrite in Li-metal-based rechargeable batteries.

Key words: lithium (Li)-metal-based battery, Li dendrite, strain gradient, depositing

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