A carbon-based 3D current collector with surface protection for Li metal anode

• Published in: Nano research 2017-04, Vol.10 (4), p.1356-1365
• Main Authors: Zhang, Ying, Liu, Boyang, Hitz, Emily, Luo, Wei, Yao, Yonggang, Li, Yiju, Dai, Jiaqi, Chen, Chaoji, Wang, Yanbin, Yang, Chunpeng, Li, Hongbian, Hu, Liangbing
• Format: Article
• Language: English
• Subjects: Accumulators; Aluminum oxide; Anodes; Anodic protection; Atomic layer deposition; Atomic layer epitaxy; Atomic/Molecular Structure and Spectra; Batteries; bio-inspired, energy storage (including batteries and capacitors), defects, charge transport, synthesis (novel materials), synthesis (self-assembly), synthesis (scalable processing); Biomedicine; Biotechnology; Carbon nanotubes; Charge distribution; Chemistry and Materials Science; Collectors; Condensed Matter Physics; Cycles; Dendrites; Electrochemistry; Electrode materials; Electrodes; Electrolytes; Electrolytic cells; Hazards; Interface stability; Lithium; Materials Science; Mechanical properties; Metals; Nanotechnology; Rechargeable batteries; Redox potential; Research Article; Solid electrolytes; Specific capacity
• ISSN: 1998-0124; 1998-0000
• DOI: 10.1007/s12274-017-1461-2

Lithium metal is considered the ideal anode material for Li-ion-based batteries because it exhibits the highest specific capacity and lowest redox potential for this type of cells. However, growth of Li dendrites, unstable solid electrolyte interphases, low Coulombic efficiencies, and safety hazards have significantly hindered the practical application of metallic Li anodes. Herein, we propose a three-dimensional （3D） carbon nanotube sponge （CNTS） as a Li deposition host. The high specific surface area of the CNTS enables homogenous charge distribution for Li nucleation and minimizes the effective current density to overcome dendrite growth. An additional conformal A1203 layer on the CNTS coated by atomic layer deposition （ALD） robustly protects the Li metal electrode/electrolyte interface due to the good chemical stability and high mechanical strength of the layer. The Li@ALD-CNTS electrode exhibits stable voltage profiles with a small overpotential ranging from 16 to 30 mV over 100 h of cycling at 1.0 mA·cm^-2. Moreover, the electrodes display a dendrite-free morphology after cycling and a Coulombic efficiency of 92.4% over 80 cycles at 1.0 mA·cm^-2 in an organic carbonate electrolyte, thus demonstrating electrochemical stability superior to that of planar current collectors. Our results provide an important strategy for the rational design of current collectors to obtain stable Li metal anodes.