Compact 3D Copper with Uniform Porous Structure Derived by Electrochemical Dealloying as Dendrite‐Free Lithium Metal Anode Current Collector

• Published in: Advanced energy materials 2018-07, Vol.8 (19), p.n/a
• Main Authors: Zhao, Heng, Lei, Danni, He, Yan‐Bing, Yuan, Yifei, Yun, Qinbai, Ni, Bin, Lv, Wei, Li, Baohua, Yang, Quan‐Hong, Kang, Feiyu, Lu, Jun
• Format: Article
• Language: English
• Subjects: 3D porous copper; Anode effect; Batteries; compact structures; Copper; Current density; Cu–Zn alloys; Dealloying; Dendritic structure; Deposition; Electrical resistivity; Electrochemical etching; Electrolytic cells; ENERGY STORAGE; Engraving; Hazards; Li metal batteries; Lithium; Mechanical properties; Solid electrolytes; Stripping; Zinc
• ISSN: 1614-6832; 1614-6840
• DOI: 10.1002/aenm.201800266

The development of lithium (Li) metal anodes Li metal batteries faces huge challenges such as uncontrolled Li dendrite growth and large volume change during Li plating/stripping, resulting in severe capacity decay and high safety hazards. A 3D porous copper (Cu) current collector as a host for Li deposition can effectively settle these problems. However, constructing a uniform and compact 3D porous Cu structure is still an enormous challenge. Herein, an electrochemical etching method for Cu–Zinc (Zn) alloy is reported to precisely engrave a 3D Cu structure with uniform, smooth, and compact porous network. Such a continuous structure endows 3D Cu excellent mechanical properties and high electrical conductivity. The uniform and smooth pores with a large internal surface area ensures well dispersed current density for homogeneous Li metal deposition and accommodation. A smooth and stable solid electrolyte interphase is formed and meanwhile Li dendrites and dead Li are effectively suppressed. The Li metal anode conceived 3D Cu current collector can stably cycle for 400 h under an Li plating/stripping capacity of 1 mA h cm−2 and a current density of 1 mA cm−2. The Li@3D Cu||LiFePO4 full cells present excellent cycling and rate performances. The electrochemical dealloying is a robust method to construct 3D Cu current collectors for dendrite‐free Li metal anodes. The electrochemical etching method is presented to prepare 3D Cu with a uniform and compact porous network. As current collector of Li metal anode, the 3D Cu with large internal surface area and enhanced mechanical properties can effectively accommodate Li metal and suppress Li dendrite growth to achieve a high performance in a Li–metal battery.