Dendrite-Free Composite Li Anode Assisted by Ag Nanoparticles in a Wood-Derived Carbon Frame

ACS Appl Mater Interfaces. 2019 May 22;11(20):18361-18367. doi: 10.1021/acsami.9b01694. Epub 2019 May 8.

Abstract

Using lithium metal as anode in lithium batteries has attracted great attention due to its ultrahigh theoretical capacity of 3860 mA h g-1. However, the uneven deposition of lithium will cause dendrites, resulting in a poor cycling performance. Herein, a dendrite-free Li composite anode is developed by anchoring Ag nanoparticles in a wood-derived carbon (WDC) frame. The composite anode is integrally formed and has enough room for Li deposition due to the aligned open channels preserved from natural wood, which can decrease anode volume change greatly during cycling. The Ag nanoparticles, serving as seeds of lithium deposition, can help in the even deposition of lithium in the channels of carbon matrix due to their lithiophilicity and then avoid lithium dendrite formation. The composite anode exhibits excellent cyclic performance over 450 h at 1 mA cm-2 and over 300 h at 3 mA cm-2. The full cell of Ag-WDC@LFP also exhibits the smallest electrochemical polarization from 0.2 to 5 C, and a stable specific capacity and a high Coulombic efficiency at 1 C after a long time cycle. These results indicate that Ag nanoparticles play an important role in restraining dendrite formation during lithium plating/stripping. The wood-derived composite cathode can achieve no lithium dendrite formation and can be applied in other storage batteries.

Keywords: Ag nanoseeds; dendrites; lithiophilicity; lithium anode; wood-derived carbon.