Robust Expandable Carbon Nanotube Scaffold for Ultrahigh‐Capacity Lithium‐Metal Anodes

• Published in: Advanced materials (Weinheim) Vol. 30; no. 32; pp. e1800884 - n/a
• Main Authors: Sun, Zhaowei, Jin, Song, Jin, Hongchang, Du, Zhenzhen, Zhu, Yanwu, Cao, Anyuan, Ji, Hengxing, Wan, Li‐Jun
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 09.08.2018
• Subjects: Anodes; Carbon; carbon nanotube paper; Carbon nanotubes; Dendritic structure; Electrochemical analysis; Electrode materials; Electrodes; Gravimetry; Lithium; lithium‐metal anodes; Materials science; Nanotubes; Rechargeable batteries; robust structure; Robustness; Scaffolds; ultrahigh capacity; carbon nanotube paper; ultrahigh capacity; robust structure; lithium-metal anodes
• ISSN: 0935-9648; 1521-4095; 1521-4095
• DOI: 10.1002/adma.201800884

There has been a renewed interest in using lithium (Li) metal as an anode material for rechargeable batteries owing to its high theoretical capacity of 3860 mA h g−1. Despite extensive research, modifications to effectively inhibit Li dendrite growth still result in decreased Li loading and Li utilization. As a result, real capacities are often lower than values expected, if the total mass of the electrode is taken into consideration. Herein, a lightweight yet mechanically robust carbon nanotube (CNT) paper is demonstrated as a freestanding framework to accommodate Li metal with a Li mass fraction of 80.7 wt%. The highly conductive network made of sp2‐hybridized carbon effectively inhibits formation of Li dendrites and affords a favorable coulombic efficiency of >97.5%. Moreover, the Li/CNT electrode retains practical areal and gravimetric capacities of 10 mA h cm−2 and 2830 mA h g−1 (vs the mass of electrode), respectively, with 90.9% Li utilization for 1000 cycles at a current density of 10 mA cm−2. It is demonstrated that the robust and expandable nature is a distinguishing feature of the CNT paper as compared to other 3D scaffolds, and is a key factor that leads to the improved electrochemical performance of the Li/CNT anodes. A lightweight yet mechanically robust carbon‐nanotube paper is reported as a free‐standing current collector to accommodate lithium (Li) metal with a Li mass fraction of 80.7 wt%, which demonstrates reversible areal and gravimetric capacities of 10 mA h cm−2 and 2830 mA h g−1 electrode, respectively, at 10 mA cm−2 for 1000 cycles with Li utilization of 90.9%.