物理化学学报 >> 2021, Vol. 37 >> Issue (1): 2009020.doi: 10.3866/PKU.WHXB202009020

所属专题: 金属锂负极

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多孔泡沫铜和硫脲协同作用构筑无枝晶锂负极

秦金利1, 任龙涛1, 曹欣1, 赵亚军1, 许海军3,*(), 刘文1,*(), 孙晓明1,2   

  1. 1化工资源有效利用国家重点实验室,北京化工大学化学学院,北京 100029State Key Laboratory of Chemical Resource Engineering, College of Chemistry, Beijing University of Chemical Technology, Beijing 100029, China
    2北京化工大学,北京软物质科学与工程高精尖创新中心,北京 100029Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, China
    3北京化工大学数理学院,北京 100029College of Mathematics and Physics, Beijing University of Chemical Technology, Beijing 100029, China
  • 收稿日期:2020-09-04 录用日期:2020-09-30 发布日期:2020-10-21
  • 通讯作者: 许海军,刘文 E-mail:hjxu@buct.edu.cn;wenliu@mail.buct.edu.cn
  • 基金资助:
    国家自然科学基金(21771018);国家自然科学基金(21875004);北京化工大学(buctrc201901);国家自然科学基金和意大利外交与国际合作部(NSFC-MAECI 51861135202);北京市自然科学基金(2192037);国家重点研发项目(2018YFB1502401);国家重点研发项目(2018YFA0702002);英国皇家学会和牛顿基金会颁发的牛顿高级奖学金(NAF\R1\191294);学校长江学者与创新研究团队项目(IRT1205);中央高校基础研究经费;中华人民共和国财政部和教育部长期补贴机制

Porous Copper Foam Co-operation with Thiourea for Dendrite-free Lithium Metal Anode

Jinli Qin1, Longtao Ren1, Xin Cao1, Yajun Zhao1, Haijun Xu3,*(), Wen Liu1,*(), Xiaoming Sun1,2   

  • Received:2020-09-04 Accepted:2020-09-30 Published:2020-10-21
  • Contact: Haijun Xu,Wen Liu E-mail:hjxu@buct.edu.cn;wenliu@mail.buct.edu.cn
  • About author:Liu Wen. E-mail:wenliu@mail.buct.edu.cn
    Xu Haijun. E-mail:hjxu@buct.edu.cn
  • Supported by:
    the National Natural Science Foundation of China(21771018);the National Natural Science Foundation of China(21875004);the Beijing University of Chemical Technology(buctrc201901);the National Natural Science Foundation of China and Ministry of Foreign Affairs and International Cooperation, Italy(NSFC-MAECI 51861135202);the Natural Science Foundation of Beijing(2192037);the National Key Research and Development Project(2018YFB1502401);the National Key Research and Development Project(2018YFA0702002);the Royal Society and the Newton Fund through the Newton Advanced Fellowship Award(NAF\R1\191294);the Program for Changjiang Scholars and Innovation Research Team in the University(IRT1205);the Fundamental Research Funds for the Central Universities, and the Long-term Subsidy mechanism from the Ministry of Finance;the Ministry of Education of China

摘要:

锂金属作为下一代储能电池的理想负极材料一直受到极大的关注,然而锂枝晶的不可控生长和负极副反应带来的低库伦效率问题严重限制了锂金属电池的发展。这里,我们提出了一种多孔泡沫铜和硫脲协同作用的策略,利用硫脲分子的超填充作用实现锂金属在多孔泡沫铜表面的均匀沉积。在电解液中添加0.02 mol·L-1硫脲作为电解质添加剂,采用多孔泡沫铜的Li||Cu半电池在循环300圈以后,库伦效率仍保持在98%以上。此外,在5C的高倍率条件下,Li||LiFePO4全电池循环300圈以后仍有94%的容量保持率。本工作为锂金属负极保护提供了一种新的策略并且该策略也可以扩展到其他金属负极保护中,非常有利于下一代高能量密度储能电池的开发。

关键词: 锂金属负极, 硫脲, 锂枝晶, 3D框架, 多孔泡沫铜

Abstract:

With the rapid development of electric vehicles and portable electronic devices, traditional lithium-ion batteries with graphite anodes cannot satisfy demands for increased energy density. Lithium metal, with a high theoretical specific capacity (3860 mAh·g-1), low density (0.534 g·cm-3), and the lowest potential (-3.040 V vs. standard hydrogen electrode), has received much attention as an ideal anode material for next-generation energy storage devices. However, the uncontrolled growth of lithium dendrites and low Coulombic efficiency caused by negative side reactions have severely hindered the development of lithium metal batteries. Here, we propose a strategy based on the synergistic effect between a porous copper foam and thiourea, which uses the "super-filling" effect of thiourea molecules to achieve the uniform deposition of lithium metal on the surface of the porous copper foam. The unique curvature enhance coverage mechanism of thiourea molecules can accelerate Li deposition rate in grooves and achieve "super-filling" growth. The porous copper foam was obtained through simple multi-step processing. Scanning electron microscopy images showed many small pores evenly distributed on the surface; these pores acted as nucleation sites for lithium deposition. With the effect of thiourea, lithium was preferentially deposited in the small pores and then filled to the top, and finally deposited uniformly on the surface of the porous copper foam. The morphologies of the different electrodes deposited with capacities of 1, 3, and 10 mAh·cm-2 demonstrated the synergistic effect between the porous copper foam and thiourea, which can inhibit the growth of lithium dendrites. Through this strategy, stable lithium plating/stripping over 500 h was achieved at a current density of 1 mA·cm-2 with a fixed capacity of 1 mAh·cm-2 while maintaining a voltage hysteresis below 20 mV. Meanwhile, greatly enhanced Coulombic efficiency and longer cycle life times were achieved: the Li||LiFePO4 full cell maintained 94% capacity after 300 cycles at 5C. Exploiting the synergy between the electrolyte and framework provides a novel approach for fabricating advanced lithium metal batteries. This work thus details a novel strategy for lithium anode protection that may also be extended to other metal anodes, thereby facilitating the development of next-generation energy storage devices.

Key words: Lithium metal anode, Thiourea, Lithium dendrite, 3D framework, Porous copper foam

MSC2000: 

  • O646