Bio-inspired Iow-tortuosity carbon host for high-performance lithium-metal anode

• 来源期刊: 国家科学评论（英文版）
• 年，卷（期）: 2019,（2）
• 页码范围: 247-256
• 页数: 10页
• 语种: 英文
• DOI: 10.1093/nsr/nwy148

摘要

Lithium metal is one of the most promising anode materials for high-energy-density Li batteries.However,low stability caused by dendrite growth and volume change during cycling hinders its practical application.Herein,we report an ingenious design ofbio-inspired low-tortuosity carbon with tunable vertical micro-channels to be used as a host to incorporate nanosized Sn/Ni alloy nucleation sites,which can guide Li metal's plating/stripping and meanwhile accommodate the volume change.The pore sizes of the vertical channels of the carbon host can be regulated to investigate the structure-performance correlation.After compositing Li,the bio-inspired carbon host with the smallest pore size (～14 μm) of vertical channels exhibits the lowest overpotential (～ 18 mV at 1 mA cm-2),most stable tripping/plating voltage profiles,and best cycling stability (up to 500 cycles) in symmetrical cells.Notably,the carbon/Li composite anode is more rewarding than Li foil when coupled with LiFePO4 in full cells,exhibiting a much lower polarization effect,better rate capability and higher capacity retention (90.6％ after 120 cycles).This novel bio-inspired design of a low-tortuosity carbon host with nanoalloy coatings may open a new avenue for fabricating advanced Li-metal batteries with high performance.