A dendrite-free composite Li anode assisted by Ag nanoparticles in wood-derived carbon frame.

Using lithium metal as anode in lithium batteries has attracted great attentions due to its ultrahigh theoretical capacity of 3,860 mA h g-1. However, the uneven deposition of lithium will cause dendrites, resulting in poor cycling performance. Herein, a dendrite-free Li composite anode is developed by anchoring Ag nanoparticles in wood-derived carbon 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 the even deposition of lithium in the channels of carbon matrix due to its lithiophilicity and then avoid lithium dendrites formation. The composite anode exhibits excellent cyclic performance over 450 hours at 1 mA cm-2 and over 300 hours at 3 mA cm-2. The full cell of Ag-WDC@LFP also exhibits a smallest electrochemical polarization from 0.2 C 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 to restrain dendrites formation during lithium plating/stripping. The wood-derived composite cathode can achieve no lithium dendrites and can be applied in other storage batteries.