Surface lithiophilicity modification with triazole to realize dendrite-free lithium metal anode

A large nucleation overpotential on most metal substrates can cause uneven nucleation of Li, causing inhomogeneous Li deposition, leading to tip effects and gradually evolve into dendrites and dead Li. Surface lithiophilicity modification is conducive to promoting Li nucleation, thus avoid the generation of dendrites and form uniform Li deposition. Herein, 3-mercapto-1,2,4-triazole (MT) is used to modify the surface of Cu foil to form lithiophilic modification layer decorated Cu electrode (MT/Cu). Due to the lone pair of electrons on N and S in the MT molecules, Li+ can be easily absorbed, thus realizing uniform and dendrite-free deposition, and improving cycling stability. After plating/stripping cycles for asymmetric cell, an average Coulombic efficiency up to 99.76 % can be achieved. When the Li-loaded composite anode (Li/MT/Cu) is matched with LiFePO4 cathode, the full cell possesses a capacity retention rate of 98.3 % after 200 cycles at 1 C, and the Coulombic efficiency throughout the process maintains over 99 %. This method of surface lithiophilicity modification is simple and effective, which can provide new ideas for the composition and modification of Li metal anodes.